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2014

Contractional Tectonics: Investigations of OngoingConstruction of the Himalaya Fold-thrust Belt andthe Trishear Model of Fault-propagation FoldingHongjiao YuLouisiana State University and Agricultural and Mechanical College, hyu9@lsu.edu

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Recommended CitationYu, Hongjiao, "Contractional Tectonics: Investigations of Ongoing Construction of the Himalaya Fold-thrust Belt and the TrishearModel of Fault-propagation Folding" (2014). LSU Doctoral Dissertations. 2683.https://digitalcommons.lsu.edu/gradschool_dissertations/2683

CONTRACTIONAL TECTONICS: INVESTIGATIONS OF ONGOING

CONSTRUCTION OF THE HIMALAYAN FOLD-THRUST BELT AND THE

TRISHEAR MODEL OF FAULT-PROPAGATION FOLDING

A Dissertation

Submitted to the Graduate Faculty of the

Louisiana State University and

Agricultural and Mechanical College

in partial fulfillment of the

requirements for the degree of

Doctor of Philosophy

in

The Department of Geology and Geophysics

by

Hongjiao Yu

B.S., China University of Petroleum, 2006

M.S., Peking University, 2009

August 2014

ii

ACKNOWLEDGMENTS

I have had a wonderful five-year adventure in the Department of Geology and

Geophysics at Louisiana State University. I owe a lot of gratitude to many people and I would

not have been able to complete my PhD research without the support and help from them.

This dissertation is dedicated to my advisor, Dr. Alex Webb, who set priorities and

motivation for my graduate studies. His constant encouragement, guidance, advice, enthusiasm

to geology, and rigorous requirements have inspired me to make progress and helped me

complete my thesis work with happiness and tears.

I also appreciate the support and inspiration I've received from my committee members

and other faculty at LSU: Dr. Gary Byerly, Dr. Barb Dutrow, Dr. Darrell Henry, and Dr. Peter

Clift for their generous time and effort in guiding and reviewing my Ph.D. work.

The thermochronologic data in this dissertation was conducted in Geologie, Technische

Universitat Bergakademie Freiberg in Germany for about 9 months. I am grateful to Dr.

Raymond jonckheere for his insight and patience to advance my knowledge of Fission track

technique. I benefited a lot from discussion with Dr. Lothar Ratschbacher and I also want to

thank him for arranging my trip in Germany. I extend my thankfulness to Bastian Wauschkuhn,

Yang Zhao for their helpful advice on fission track sample preparation and data analysis.

I would like to thank Dr. Kyle Larson for analyzing quartz c-axis fabrics, Rick Young for

making thin sections, and Kyle Barber for rock cutting.

I want to extend my appreciation to my fellow graduate students Dennis Donaldson,

Cindy Colόn, and Chase Billeaudeau in the Structural Geology group. Their helps and

discussions have been always encouraging me to move forward.

iii

Finally, I would like to express my gratefulness to my Husband Dian He and my parents

in law. I owe a great debt of gratitude to my parents. Without their sacrifices and support, I

would have not even started this journey abroad yet.

The Himalayan research was supported by the start-up grant from Louisiana State

University and the Louisiana Board of Regents grant to Dr. Webb, the AAPG and GSA graduate

student research grants to Hongjiao Yu.

The Uncompahgre Uplift research is my intern project in Shell Oil Company. I would

like to thank J.P. Brandenburg, David Wolf, Steve Naruk, David Kirschner, and Michael Gross

for their guidance and discussions when I was interning at Shell.

iv

TABLE OF CONTENTS

ACKNOWLEDGMENTS…………………………………………………………………...……ii

ABSTRACT………………………………………………..…………………………………….vi

CHAPTER 1

INTRODUCTION…………………………………………………………………..…………….1

1.1 The Himalayan Fold-thrust Belt ………..………………………………………………….1

1.2 The Uncompahgre Uplift …..………………………………………………………………3

CHAPTER 2

EXTRUSION VERSUS DUPLEXING MODELS OF HIMALAYAN MOUNTAIN BUILDING:

DISCOVERY OF THE PABBAR THRUST, NW INDIAN HIMALAYA …………...........……5

2.1 Introduction…………………………………………………………………….…...………5

2.2 Geology of the Northwest Indian Himalaya ……………………………………………...11

2.2.1 Stratigraphic Diversity……….………………………………….……………………12

2.2.2 Tectonic framework....……………………..…………………………….…………...14

2.3 Methods……………………………………………………………………………………17

2.3.1 Field Mapping………………………………………………..……………………….17

2.3.2 Microstructural Analysis ………………...……………………….…………………..17

2.4 Results of Structural Geology Mapping ……...…………………………………………..18

2.4.1 Field Observations …………………………………………………………………...21

2.4.1.1 Tharoch Transect.………………………………..………………………………21

2.4.1.2 Lower Pabbar Transect …………………..……......…………………………….26

2.4.1.3 Tons River Transect…..…..……………………………………………….……..28

2.4.2 Quartz Microstructures ………………………………….………………...…………30

2.5 Discussion …………………………………...……………………………………………31

2.5.1 Kinematic Evolution of the Tons Thrust, Pabbar Thrust and Berinag Thrust……......32

2.5.2 Along-strike Variations of Thrust Geometries and Stratigraphic Correlation…...…...33

2.6 Conclusions………………………………………………………………………………..38

CHAPTER 3

KINEMATIC EVOLUTION OF HIMALAYAN OROGEN CONSTRAINED BY NEW

FISSION TRACK ANALYSIS IN NW INDIA…..…………………………….……………….41

3.1 Introduction……………………………………………………………………………......41

3.2 Methods: Apatite and Zircon Fission Track Analysis………….…………………………42

3.3 Results………………………………………………………………………………..........46

3.3.1 Fission Track Analysis…………………………………………………………..........46

3.3.2 Interpretation…….………….…………………………………………………….......49

3.4 Balanced Palinspastic Reconstruction Across the NW Indian Himalaya…………………51

3.4.1 Restoration ca. 28 Ma……………..……………………………………………….....54

3.4.2 Restoration ca. 20 Ma……………..……………………………………………….....54

3.4.3 Restoration ca. 13 Ma……………..……………………………………………….....54

3.4.4 Restoration ca. 8.1 Ma…………….……………………………………………….....55

3.4.5 Restoration ca. 5.2 Ma…………….……………………………………………….....55

v

3.5 Discussion: Extrusion vs. Duplexing Models of Himalayan Mountain Building……...…56

3.6 Conclusions……...….……………………………………………………………………..58

CHAPTER 4

KINEMATIC TRISHEAR MODEL OF FAULT-PROPAGATION FOLDING TO PREDICT

DEFORMATION BANDS, COLORADO NATIONAL MONUMENT, NW UNCOMPAHGRE

UPLIFT, USA……………………………………………………………………………………59

4.1 Introduction………………………………………………………………………………..59

4.2 Geology Background……….…...……………………………………………………..….62

4.2.1 Tectonic History of the Uncompahgre Uplift………………………………………...62

4.2.2 Major Stratigraphy…...…………...…………………………………………………..65

4.2.3 Major Faults in CNM, Uncompahgre Uplift…….……………………………………66

4.3 Methods and Data……………………………………………………………………..67

4.3.1 Method: Kinematic Trishear Model of Fault-propagation Folding……………...…...67

4.3.2 Data: Characteristics of Deformation Bands in CNM………..………………………68

4.4 Results……………………………..……………………………………………………....69

4.4.1 Balance Reconstruction………….………………….……………………………......69

4.4.1.1 Cross Section Reconstruction along the East Kodels Canyon...………..………..70

4.4.1.2 Cross Section Reconstruction along the North Canyon…..…………..………..71

4.4.1.3 Cross Section Reconstruction along the East Canyon…..…………….………..71

4.4.2 Strain Calculation………...……………………………..…………………….……....75

4.5 Discussion………….…………...…………………………………………………………77

4.6 Conclusions……………………………………………………………………..…………79

CHAPTER 5

SUMMARY AND CONCLUSIONS………..…………………………………………………..81

5.1 Growth of the Himalayan Fold-thrust belt Dominated Duplexing Processes…...….……..81

5.2 Kinematic Trishear Fault-propagation Folding Model to Predict Deformation Bands…...83

REFERENCES………..………………………………………………………………………....85

APPENDIX A:

APATITE FISSSION TRACK DATA.……………………………………………...…………108

APPENDIX B:

ZIRCON FISSSION TRACK DATA...……………………………………………...…………114

PLATE 1:

SEQUENTIAL CROSS-SECTION RESTORATION ACROSS THE NW INDIAN

HIMALAYA………………………….……………………………………………...…………127

VITA……………………………………………………………………………………………128

vi

ABSTRACT

This dissertation focuses on the kinematic evolution of contractional tectonics: the

Himalayan fold-thrust belt along the collisional orogenic belts, and growth of the basement-

cored monoclines in Colorado Plateau.

Ongoing Himalayan growth is generally thought to be dominated by duplexing and/or

extrusion processes. Duplexing models highlight accretion of material from the subducting plate

to the over-riding orogenic wedge, whereas extrusion models focus on up-dip translation of a

block bounded by out-of-sequence faults. Here, a primary outstanding question involves the

uncertain relationship of the Berinag thrust and the Tons thrust, structures with displacements

of >80 km and >40 km, respectively. The uncertainty allows the complete range of duplexing

and extrusion processes for the integrated kinematic history since the Middle Miocene.

To address this issue, field mapping, kinematic analysis, and analysis of quartz

recrystallization textures were performed. Our results reveal a new discovery: a ~ 450 m thick

top-to-southwest shear zone, termed the Pabbar thrust. The Pabbar thrust placed the Outer Lesser

Himalayan Sequence (the Tons thrust hanging wall) directly on the Berinag Group (the Berinag

thrust hanging wall). This discovery requires that the Pabbar thrust developed first, followed by

footwall accretion of the Berinag-Tons thrust sheet, operating as a single structure. The Berinag

thrust and Tons thrust are in fact the same structure. Low temperature thermochronological data,

and a line-length balanced palinspastic reconstruction across the NW Indian Himalaya place

robust constraint on Himalayan mountain building process: (1) Late Oligocene–Middle Miocene

emplacement of the Great Himalayan Crystalline Complex (GHC) and juxtaposing of the THS

atop the Lesser Himalayan Sequence (LHS). (2) Middle–Late Miocene accretion of the Berinag-

vii

Tons thrust sheet; and (3) subsequent growth via a hinterland-dipping upper crustal duplexing

and an antiformal stack of mid-crustal horses developed simultaneously.

Trishear provides an alternative model of fault-propagation. It is successfully applied to

create balanced cross sections for the monoclines in Uncompahgre Uplift. Forward modeling of

strains around the fault tip zone demonstrates excellent agreement with field-based strain

calculated from deformation bands, and can explain distribution and orientation of deformation

bands in eolian sandstone.

1

CHAPTER 1

INTRODUCTION

1.1 The Himalayan Fold-thrust Belt

The Himalaya is an excellent natural laboratory for studying growth of fold-thrust belts

because it is active, has rapid convergence along a ~2500 km long arc, and is impacted by the

powerful climatic system of the Asian monsoon (e.g., Hodges, 2000; Avouac, 2003; 2008; Yin,

2006). This system has received intense study over the last decade, which has produced

numerous hypotheses and discoveries of interactions between climatic, erosional, and tectonic

processes (e.g., Beaumont et al., 2001; 2004; Hodges et al., 2001; Zeitler et al., 2001, Burbank et

al., 2003; Vance et al., 2003; Bookhagen et al., 2005a; 2005b; Grujic et al., 2006; Montgomery

and Stolar, 2006; Dupont-Nivet et al., 2007; Rahl et al., 2007; Clift et al., 2008; Jessup et al.,

2008; Robl et al., 2008; Royden et al., 2008; Wobus et al., 2008; Boos and Kuang, 2010;

Armstrong and Allen, 2011; Iaffaldano et al., 2011). However, first-order aspects of the

kinematics of ongoing mountain-building remain uncertain, which is generally thought to be

dominated by duplexing and/or extrusion processes. Duplexing models are dominated by

accretion of material from the downgoing plate to the over-riding wedge, with only minor out-of-

sequence deformation. Extrusion models highlight southward extrusion of a fault-bounded block,

with an out-of-sequence thrusting below and a normal faulting above.

Exploration is largely focused on a ~20-50 km wide orogen-parallel band of rapid uplift

and exhumation, marked by a steep topographic rise, that first appears ~70-100 km north of the

range front. Extensive efforts to understand the kinematic development across this zone include

structural balancing (e.g., DeCelles et al., 2001; Robinson et al., 2006; Robinson, 2008;

McQuarrie et al., 2008; Mitra et al., 2010; Yin et al., 2010; Long et al., 2011), thermochronology

2

(e.g., Wobus et al., 2003; Thiede et al., 2004; 2005; 2009; Huntington et al., 2006; Blythe et al.,

2007; Deeken et al., 2011), thermobarometry coupled to geochronology (e.g., Harrison et al.,

1997; Catlos et al., 2001; 2004; Robinson et al., 2003; Bollinger et al., 2004), and

thermokinematic and mechanical modeling (e.g., Godard et al., 2006; Godard and Burbank, 2011;

Wobus et al., 2006; Whipp et al., 2007; Herman et al., 2010). The proposed out-of-sequence

thrust faulting coincides with trace of the Munsiary thrust. The hanging wall of the proposed out-

of-sequence coincides in map view with the proposed duplexing region along a mid-crust ramp

in a ~20-50 km wide. Detailed thermokinematic modeling of thermochronometric data from this

zone has failed to rule out either duplexing or out-of-sequence models (Wobus et al., 2006;

Whipp et al., 2007; Herman et al., 2010).

Analog (sandbox) and numerical simulations of fold-thrust belt evolution highlight the

importance of strength heterogeneities and erosion (Konstantinovskaia and Malavieille, 2005;

2011; Bonnet et al., 2007; Stockmal et al., 2007). Experiments with multiple decollements,

erosion and syntectonic sedimentation results in the development of an hinterland antiformal

stacking underlying a zone of maximum exhumation, and hinterland dipping duplex by upper

crustal foot accretion or imbricated stacks by frontal accretion towards the foreland

(Konstantinovskaia and Malavieille, 2005; Naylor et al., 2005; Bonnet et al., 2007; Stockmal et

al., 2007; Malavieille, 2010).

The proposed study will investigate the kinematics of ongoing mountain building, in

particular the development of the rapid exhumation zone, by integrated geological research

across the NW Indian Himalaya. Our work is composed of three components: (1) structural and

kinematic mapping combined with microstructural investigations to address key questions about

the regional structure; (2) apatite and zircon fission track thermochronology to address the

3

important regional gap in such data, to the south of the zone of rapid uplift; (3) interpretation of

data from the first two research components via balanced palinspastic reconstruction.

1.2 The Uncompahgre Uplift

The Uncompahgre uplift is one of several NW-SE trending anticlines in the Colorado

plateau. This area experienced three major tectonic events: 1) Proterozoic extension generated

the basement-penetrating normal faults (e.g., Marshak and Paulsen, 1996; Karlstrom and

Humphreys, 1998; Marshak et al., 2000; Timmons et al., 2001; Whitmeyer and Karlstrom,2007);

2) The Late Paleozoic Ancestral Rockies orogeny (320-245 Ma) created a series of basins and

basement-core uplifts by crustal shortening on high-angle reverse and thrust faults (e.g., Kluth

and Coney, 1981; Bally et al., 1989; Ye et al., 1996); and 3) The Late Cretaceous to middle

Eocene (~70-50 Ma) Laramide Orogeny generated a series of highly asymmetrical, fault-cored

anticlines via reactivation of inherited Precambrian basement faults (e.g., Stearns and Jamison,

1977; Brewer et al., 1982; Allmendinger et al., 1982; Heyman, 1983; Heyman et al., 1986;

Brown, 1988, 1993; Blackstone, 1993; Huntoon, 1993; Schmidt et al., 1993; Foos, 1999;

Marshak et al., 2000; Erslev et al., 2001; Bump and Davis, 2003; Bump, 2004; Erslev and

Koenig, 2009; Brandenburg et al., 2012). This study focuses on the Laramide monoclines

because classic deformation bands in eolian sandstone are associated with the growth of those

fault-core monoclines (e.g., Jamison 1979; Jamison and Stearns, 1982). Those basement-cored

monoclines are thought to be developed by fault-propagation folding (e.g., Erslev, 1991; Erslev

and Rogers, 1993; Kellogg et al., 1995; Erslev and Selvig, 1997; Tindall and Davis, 1999;

Brandenburg et al., 2012). The traditional kink-band based fault-propagation folding features

angular fold hinges, uniform dips and constant thickness of fold limbs due to homogeneous

strain as a result of layer-parallel shear, and fixed fault propagation/slip ratio (P/S = 2) (e.g.,

4

Suppe, 1983; Suppe and Medwedeff, 1990). Those characteristics of kink-band based fault-

propagation folding failed to explain inclined Precambrian basement-Mesozoic rock contact,

curved fold hinges and thickening and thinning of fold limbs. Previous workers in this area

propose that multiple faults spread from the main thrust can create a triangular shape of

basement rocks that allow the rotation of the contact (e.g., Scott et al., 2001). However, there is

no geophysical data to support the existence of this kind of main thrust.

Trishear provides an alternative model of fault-propagation folding characterized by

heterogeneous strain generated by inclined shear in a triangular zone above the fault tip, which

commonly exhibits curved hinges, broad crested anticlines, non-uniform dips, and changing

thickness of fold limbs (e.g., Erslev, 1991; Allmendinger, 1998; Hardy and Allmendinger, 2011;

He et al., 2014 in review). Trishear model has already been applied to other monoclines in the

Colorado Plateau to successfully explain the geological features there (e.g., Erslev and Selvig,

1997; Cristallini and Allmendinger, 2001; Bump, 2003; Cristallini et al., 2004; Brandenburg et

al., 2012).

In this study, the trishear model is applied to reconstruct the basement-cored monocline

growth in Uncompahgre uplift along three balanced cross sections. The best-fit parameters are

determined for fault movement from reconstruction, which are used later for forward trishear

modeling of the target fault movement to calculate corresponding maximum shortening strain.

The modelling strain demonstrates excellent agreement with field-based strain calculated from

deformation bands, and can explain distribution and orientation of deformation bands in eolian

sandstone. The correlation may have significant implications with regard to better constraining

on the fluid pathways around faults because of low permeability of deformation bands.

5

CHAPTER 2

EXTRUSION VERSUS DUPLEXING MODELS OF HIMALAYAN

MOUNTAIN BUILDING: DISCOVERY OF THE PABBAR THRUST, NW

INDIAN HIMALAYA

2.1 Introduction

Knowledge of ongoing orogenic growth processes along the Himalayan front of the

India-Asia collision has expanded considerably in recent years. Along- and across-strike

variations in large-scale kinematics have revealed the importance of river erosion and radial

expansion in focusing deformation (Montgomery and Stolar, 2006; Murphy et al., 2009), and the

range continues to serve as a primary testing ground for climate-erosion-tectonic interaction

models (e.g., Grujic et al., 2006; Adlakha et al., 2013; Thiede and Ehlers, 2013; Scherler et al.,

2014). It has been demonstrated that climate-driven changes in orogenic topography can produce

resolvable changes in plate kinematics (Iaffaldano et al., 2011). Many of these discoveries

provide a new three-dimensional understanding of the orogenic evolution. Nevertheless, ongoing

Himalayan growth is primarily controlled by essentially two-dimensional arc-perpendicular

shortening. This shortening is generally thought to be dominated by duplexing and/or extrusion

processes.

Duplexing models are dominated by accretion of material from the downgoing plate to

the over-riding wedge, with only minor out-of-sequence deformation (e.g., Schelling and Arita,

1991; Robinson et al., 2003; Bollinger et al., 2004; Konstantinovskaia and Malavieille, 2005;

Herman et al., 2010; Grandin et al., 2012). Duplexing may occur through any or all of three

processes: frontal accretion involving forward propagation of the frontal thrust (e.g., Schelling

and Arita, 1991), expansion of the orogen via incremental accretion along the basal shear zone

(e.g., Searle et al., 2008), and discrete accretion of km-to-10 km-scale thrust horses along ramps

6

of the Himalayan sole thrust (Figure 2.1A, 2.1B, 2.1C) (e.g., Robinson et al., 2003; Bollinger et

al., 2004; Robinson, 2008; Webb, 2013). Extrusion models also involve such accretion, but

explain a zone of rapid exhumation and steep physiography across the Himalayan hinterland via

southward extrusion of a fault-bound block, with major out-of-sequence thrust faulting below

and normal faulting above (Figure 2.1D) (e.g., Harrison et al., 1997; Hodges et al., 2001; Wobus

et al., 2005; Whipp et al., 2007; McDermott et al., 2013). The only duplexing process that can

Figure 2.1 Simplified kinematic models for ongoing growth of the Himalayan fold-thrust belt.

(A) Frontal accretion through forward-propagation of a basal thrust (e.g., Schelling and Arita,

1991). (B) Out-of-sequence faulting (e.g., Harrison et al., 1997). (C) Discrete duplexing of thrust

horses from the downgoing plate to the fold-thrust belt (e.g., Bollinger et al., 2004). (D)

Expansion of the orogen via incremental accretion along the basal shear zone (e.g., Searle et al.,

2008).

7

explain this rapid exhumation zone is enhanced accretion along ramps (Figure 2.1C), which can

produce rapid uplift via antiformal stacking (Bollinger et al., 2004; Konstantinovskaia and

Malavieille, 2005, McQuarrie et al., 2014).

These models may be tested by reconstructing Himalayan fold-thrust belt growth since

the Middle Miocene, because it is generally thought that the deformation modes of this period

are broadly consistent with ongoing processes (Lyon-Caen and Molnar, 1985; DeCelles et al.,

2001; Hodges et al., 2001; Robinson et al., 2003; Bollinger et al., 2004; Yin, 2006). Orogenic

growth over the last ~15-10 Ma has been mostly achieved by accretion and deformation of the

Lesser Himalayan Sequence (LHS), a package of rocks which dominates the southern half of the

Himalaya (Gansser, 1964). Therefore, we set out to reconstruct the deformation of the LHS in a

key region, the northwest Indian Himalaya (Figure 2.2). This region provides a specific

advantage: it preserves the most diverse LHS stratigraphy of the range (e.g., Valdiya, 1980;

Célérier et al., 2009a; McKenzie et al., 2011; Webb et al., 2011a), and thus offers the best

opportunity to construct a high resolution understanding of regional structural geometry.

Recent investigations of the northwest Indian Himalaya have significantly advanced our

knowledge of the Lesser Himalayan structural development here (Célérier et al., 2009a; 2009b;

McKenzie et al., 2011; Webb et al., 2011a; Webb, 2013). Most work has increasingly suggested

a dominant role for duplexing processes (e.g, cf. Thiede et al., 2004 vs. Thiede and Ehlers, 2013),

but our knowledge of basic structural geometry remains too fragmentary to resolve the issue. A

primary outstanding question involves the relationship of the Berinag thrust and the Tons thrust,

structures with displacements of >80 km and >40 km, respectively (Figure 2.2). These thrusts are

adjacent, yet have no known intersection, and this uncertainty allows that the complete range of

8

Figure 2.2 (A) Regional geological map of the central northwestern Indian and west Nepal

Himalaya. Main sources are Bhargava (1976), Valdiya (1980), Jain and Anand (1988), Singh and

Thakur (2001), Robinson et al. (2006), Célérier et al. (2009), Webb et al. (2011a), and our

observation. In west Nepal Himalaya, the Ramgarh thrust, placing the Paleoproterozoic rocks

(Ranimata-Kushma Formation) of the Lesser Himalaya upon younger Lesser Himalaya rocks or

foreland basin deposits, is labeled as the Berinag thrust since their hanging wall rocks have

identical lithology, age (~1.8 Ga), and metamorphic grade (e.g., Miller et al., 2000; DeCelles et

al., 2001; Pearson and DeCelles, 2005; Richards et al., 2005; Célérier et al., 2009a). Recent

detrital zircon U-Pb dating of hanging wall rocks of the Ramgarh thrust (south of the Almora

klippe) mentioned by Valdiya (1980) in northwest Indian Himalaya indicates the same age as the

Outer LHS (~800Ma) (Célérier et al., 2009a), therefore we interpreted it as a minor local thrust

duplicating the Outer LHS rocks in our map. Cross section A-A’ is show in Figure2.2 B; Field

observation shows the Deoban-Damtha Groups were highly deformed at 100-m scale (Webb et.

al., 2011a). Here the Deoban-Damtha groups developed a hinterland-dipping duplex via discrete

horses at ~km scale without considering the internal deformation, so the surface dip data is not

fully consistent with the cross section construction. As discussed in Webb (2013), a mushward

duplex is another possibility, with similar areal and line length balance results. Positions of

Figure 2.4 and figure 2.5 are outlined in black boxes in Figure 2.2 A.

9

A

B

10

extrusion and duplexing processes discussed above provide viable models for their integrated

kinematic history (Figure 2.3) (Webb et al., 2011a).

Figure 2.3 Possible geometric and kinematic relationships of Tons and Berinag thrusts, proposed

by Webb et al. 2011. (A) The Tons thrust terminates along the Berinag thrust; (B) the Berinag

thrust terminates along the Tons thrust; (C) the Berinag thrust and Tons thrust are a single

structure, such that the distinct hanging wall rocks are separated by a depositional contact.

Map relationships suggest that the Berinag and Tons thrusts must intersect in the region

of the upper Tons River Valley (Webb et al., 2011a). We performed field mapping, kinematic

analysis, and analysis of quartz recrystallization textures here to determine the relationship of

these two structures. We found that the hanging walls of the two faults are divided by a third

structure, which we term the Pabbar thrust. This discovery 1) requires that discrete duplexing

processes dominated growth of the LHS in northwest India and 2) resolves a major stratigraphic

continuity problem across the India – west Nepal border.

11

2.2 Geology of the Northwest Indian Himalaya

The Himalaya has a simple architecture that persists throughout the northwest Indian

Himalaya: it is dominated by three units that are largely defined by their structural positions.

From north to south, these are the Tethyan Himalayan Sequence (THS), the Greater Himalayan

Crystalline complex (GHC), and the LHS (e.g., Heim and Gansser, 1939; Gansser, 1964; Le Fort,

1975; Burg et al., 1984; Burchfiel et al., 1992). Protoliths for all three units are pre-collisional

strata of the northern portions of the Indian craton (e.g., Gansser, 1964; Myrow et al., 2003; Yin

2006; McKenzie et al., 2011; Webb et al., 2013; McQuarrie et al., 2014). The units have been

long recognized as a dominantly north-dipping, three-layer stack partitioned by two faults, the

South Tibet detachment (STD) above and the MCT below (e.g., Le Fort, 1996; Hodges, 2000;

Yin and Harrison, 2000; DeCelles et al., 2001). In recent years, this understanding has been

modified due to detection of a branch line joining the STD with the MCT across the southern

Himalaya (Yin, 2006; Webb et al., 2007; 2011a; 2011b; Kellett and Grujic, 2012). It is thus

demonstrated that the Tethyan Himalayan Sequence is juxtaposed atop the Greater Himalayan

Crystalline complex along the STD in the northern Himalaya, whereas in the southern Himalaya

the Tethyan Himalayan Sequence occurs directly atop the LHS along the MCT. The Greater

Himalayan Crystalline complex is bounded by the STD above and the MCT below, and by the

merger of these faults in the southern Himalaya. The LHS is restricted to the MCT footwall, and

it is locally intercalated along depositional contacts and thrust faults with deformed Cenozoic

foreland basin strata (e.g., West, 1939; Valdiya, 1980). These latter rocks are termed the Sub-

Himalayan Sequence, and these are separated from the undeformed foreland along the

discontinuously exposed Main Frontal thrust, i.e., the leading surface expression of the

Himalayan sole thrust (e.g., Lavé and Avouac, 2000).

12

2.2.1 Stratigraphic Diversity

The stratigraphic diversity that distinguishes the southern portions of the northwest

Indian Himalaya consists of intercalated Sub-Himalayan strata and four fault-bound LHS

stratigraphic packages: the Neoproterozoic–Cambrian Outer Lesser Himalayan Sequence (Outer

LHS), the Paleoproterozoic–Neoproterozoic Damtha and Deoban Groups, the Paleoproterozoic

Berinag Group, and the Paleoproterozoic Munsiari Group (Figure 2.2; Table 2.1) (Auden, 1934;

Valdiya, 1980; Célérier et al., 2009a; Webb et al 2011a). Most of these units have along-strike

equivalents along the length of the arc, but Outer LHS exposure is limited to the northwest

Indian Himalaya (Table 2.1).

Previous work in this area correlates part of the Outer LHS with the Berinag Group (e.g.,

Valdiya, 1980; Srivastava and Mitra, 1994). However, subsequent detrital zircon geochronology

and other geochemical data invalidate this inference because the sequences have distinct age

differences of ~1 Gyr (e.g., Ahmad et al., 2000; Richards et al., 2005; McKenzie et al., 2011;

Webb et al., 2011a). Field observations can also commonly distinguish these two units (e.g.,

Célérier et al., 2009a). The Berinag Group is dominated by thick bedded, medium-to-coarse

grained, greenschist-facies (sericitic) quartzite of white to green color. In contrast, previously-

correlated quartzite in the Outer LHS (i.e., of the Shimla Group) (Table 2.1) is medium-to-thick

bedded, fine-to-medium grained, with varying degrees of metamorphism ranging up to

greenschist facies, and of white to grey-brown color.

The Damtha Group is a thick succession of purple, white, brown graywackes succeeded

by fine-to medium grained quartzite (e.g., Rupke, 1974; Valdiya, 1980). The overlying Deoban

Group is an extensive succession of stromatolite-bearing grey, white, and pink dolomite and

limestone (e.g., Rupke, 1974; Valdiya, 1980; Raha and Sastry, 1982; Srivastava and Mitra, 1994;

13

14

Srivastava and Kumar, 2003; Tewari, 2003). The Munsiari Group is dominated by two gneissic

lithologies: ~1.85 Ga Wangtu augen gneiss and the Paleoproterozoic Jeori metasedimentary

gneiss, which includes garnet-, kyanite-, and sillimanite-bearing metapelitic rocks (Vannay and

Grasemann, 1998; Jain et al., 2000; Miller et al., 2000; Chambers et al., 2008).

At the western and northern limits of our study area, LHS rocks are overlain by Tethyan

Himalayan Sequence and Greater Himalayan Crystalline complex rocks along the MCT. Tethyan

Himalayan Sequence rocks here are psammitic and pelitic Neoproterozoic metasedimentary

rocks, intruded by early Paleozoic granitoids, metamorphosed at upper greenschist- to

amphibolite-facies conditions (e.g., Epard et al., 1995; Vannay and Grasemann, 1998; Wiesmayr

and Grasemann, 2002; Leger et al., 2013). The GHC is dominated by similar protoliths that have

been metamorphosed at amphibolite-facies conditions (e.g., Frank et al., 1977; Vannay and

Grasemann, 1998; Manikavasagam et al., 1999). Discontinuous slivers of ~1.85 Ga mylonitic

augen gneiss up to ~1.5 km thick occur within the MCT shear zone itself and are termed the

Baragaon gneiss (Trivedi et al., 1984; Miller et al., 2000; Webb et al., 2011a). These rocks are

correlative to the Wangtu gneiss and fit within the broader designation of “Ulleri” augen gneiss,

as described by Kohn et al. (2010).

2.2.2 Tectonic Framework

The major faults of the MCT footwall in northwestern India include, from northeast to

southwest, (1) the Munsiari thrust, (2) the Berinag thrust, and (3) the Krol-Tons thrust system

(e.g., Auden, 1934; Valdiya, 1980; Célérier et al., 2009a). These thrusts accommodated top-SW

motion and can be generally characterized by dominant hanging wall stratigraphy: the Munsiari

thrust underlies the Munsiari Group, the Berinag thrust underlies the Berinag Group, and the

15

Krol-Tons thrust system underlies the Outer LHS. Across the region these structures are folded

into numerous ~10 km-scale windows and klippen.

The Munsiari thrust can be traced along most of the central Himalaya (e.g., Sharma, 1977;

Valdiya, 1980; Jain and Anand, 1988; Upreti, 1999; Yin, 2006; Célérier et al., 2009a, 2009b),

and is referred to MCT-I in central Nepal (Bordet et al., 1972; Arita, 1983). Thermochronologic

data sets along the length of this thrust suggest it was active in the Late Miocene or later (e.g.,

Harrison et al., 1998; Catlos et al., 2004; Vannay et al., 2004). Two local kinematic models are

proposed for development of this thrust: 1) it is an out-of-sequence thrust that accounts for ≥10

km of exhumation of the LHS (e.g., Harrison et al., 1997; Thiede et al., 2004); 2) it underlies an

underplated thrust sheet within the LHS duplexing (e.g., Robinson et al., 2003; Bollinger et al.,

2004; 2006; Yin, 2006) and any out-of-sequence heave is late and minor (≤3 km) (Webb, 2013).

The Berinag thrust is cut by the Munsiari thrust. The southern exposure of the thrust - in

the Munsiari thrust footwall - places the Berinag Group over the Deoban and Damtha Groups,

whereas the northern thrust exposure - in the Munsiari thrust hanging wall - places the Berinag

Group over the Wangtu gneiss (Valdiya, 1980; Srivastava and Mitra, 1994; Vannay and

Grasemann, 1998; Vannay et al., 2004; Célérier et al., 2009a; Webb et al., 2011a). Minimum

displacement along the Berinag thrust is 80 km, as estimated from across-strike thrust exposures

placing older atop younger rocks (Figure 2.2).

The Krol thrust underlies the Outer LHS along the southern flank of these rocks, whereas

the Tons thrust is the name used to describe the underlying thrust farther north (e.g., Srikantia

and Sharma, 1976; Valdiya, 1980; Célérier et al., 2009a). These may be generally considered the

same structure, with the proviso that a variety of subsequent, cross-cutting structures may

juxtapose Outer LHS rocks against Sub-Himalayan Sequence rocks to the south and yet be

16

termed the “Krol thrust” (or “Main Boundary thrust”) in literature (e.g., Meigs et al., 1995). Such

later structures would not correlate with the Tons thrust. The footwall of the Tons thrust is

dominated by Deoban and Damtha Group rocks which are locally depositionally overlain by

rocks of the Singtali and/or Subathu Formations (Pilgrim and West, 1928; Jain, 1972; Bhargava,

1976; Valdiya, 1980). Because the Singtali and Subathu Formations locally form the immediate

Tons thrust footwall and these units are Cretaceous and Paleogene, respectively, the Tons thrust

must be a Cenozoic structure. Minimum displacement along the Tons thrust is 40 km, as

determined from across-strike exposure (Figure 2.2). Célérier et al (2009a) proposed that the

Tons thrust accommodated south-directed motion during the Eocene–Oligocene, earlier than

MCT movement, such that the later MCT would represent a massive out-of-sequence structure

cutting across the earlier Tons thrust. Alternatively, it may represent a thrust horse accreted to

the over-riding plate during the mid- to late- Miocene (Webb et al., 2011a; Webb, 2013).

Preliminary thermochronologic work (Yu et al., in prep.) favors the second hypothesis.

Both the Berinag and Tons thrust faults have discontinuous lenses of Ulleri

Paleoproterzoic granitic gneisses (~1.85 Ga) exposed along them, ranging in scale up to km

thicknesses (Figure 2.2) (Valdiya, 1980; Célérier et al., 2009a). These exposures are generally

analogous to the correlative Baragaon gneiss exposures along the MCT zone (Trivedi et al., 1984;

Miller et al.2000; Webb et al., 2011a). These relationships require either that both Berinag and

Tons thrust hanging wall rocks were deposited on Ulleri gneiss or both thrust systems accreted

slivers of this rock during translation.

The interaction of the Berinag thrust and the Tons thrust is uncertain in terms of both

geometry and kinematics. Three proposed geometries of these two thrusts are: (A) the Tons

thrust terminates along the Berinag thrust; (B) the Berinag thrust terminates along the Tons thrust;

17

(C) the Berinag thrust and Tons thrust are a single structure (Figure 2.3) (Webb et al., 2011a).

The first two geometries can be accomplished by either out-of-sequence faulting or duplexing. In

the third case, the different rocks of the Berinag and Tons thrust hanging walls are separated

along a depositional contact. In the following, we show that the Berinag thrust terminates along

the Tons thrust, and their hanging walls are separated by a third structure, which we term the

Pabbar thrust.

2.3 Methods

2.3.1 Field Mapping

We conducted mapping and sampling in the Tons valley along three local rivers, listed

from west to east: the Tharoch river, the lower Pabbar river, and the upper Tons river (Figure

2.4 and Figure 2.5). Lithology and deformation features of major structures were documented in

the field.

2.3.2 Microstructural Analysis

Microstructures resulting from dynamic deformation of quartz were used to semi-

quantitatively to constrain regional deformation temperature. Three quartz grain-boundary

recrystallization regimes have been defined in both experimental and natural quartz samples to

generally correlate with deformation temperature, although other factors such as strain rate and

inclusion populations can also modulate these effects (e.g., Hirth and Tullis, 1992; Stipp et al.,

2002): bulging recrystallization (BLG, 280-380 °C); subgrain rotation recrystallization (SGR,

380-500 °C), and grain boundary migration (GBM, >500 °C). The SGR regime can be further

sub-divided into SGR-I (380-450 °C) and SGR-II (450-500 °C) (Figure 2.6).

18

Figure 2.4 Local geological map and equal area stereoplots along the lower Pabbar River area in

the Tons valley and its cross section A-A’. The thick dashed line indicates the leading edge of

the Berinag Group. The map pattern shows the Tons hanging wall directly overlaying the

Berinag hanging wall along a thrust contact, the Pabbar thrust. Thrust symbols are same in as in

the figure 2.2 Locations of field photographs and microphotographs are annotated.

2.4 Results of Structural Geology Mapping

Map relationships indicate that the Berinag and Tons thrusts must intersect in the region

of the upper Tons River Valley (Webb et al., 2011a). We conducted mapping and sampling in

the Tons valley along three local rivers, listed from west to east: the Tharoch river, the lower

Pabbar river, and the upper Tons river (Figure 2.4 and Figure 2.5). Previous work in the Tons

19

Figure 2.5 Geological map and cross section C-C’ along the upper Tons River area based on the

map from Jain and Anand (1988) and our own observations. The map pattern and cross section

show that the Berinag thrust was truncated by the out-of-sequence Munsiari thrusting. Black

color structural data are from this study; white color structural data are taken from Jain and

Anand (1988), and were used for cross section construction. Locations of field photographs and

microphotographs are annotated.

20

valley established the position of MCT shear zone and the Munsiari thrust zone (e.g. Bhargava,

1976; Srikantia and Bhargava 1988; Jain and Anand, 1988).

Figure 2.6 Characteristic microstructures of three dynamic recrystallization mechanisms of

quartz in the study area. (a) Bulging recrystallization (BLG) (280-380°C). Inhomogeneously,

slightly flattened detrital grains exhibit irregular and patchy undulatory extinction. The grain

boundaries appear diffuse. Very fine recrystallized grains occur locally along the grain

boundaries. Proportion of recrystallized grains (%) is <15%. (b) Subgrain rotation

recrystallization (SGR-I) (380-450°C). Homogeneously elongated porphyroclasts exhibit

irregular and patchy undulatory extinction. Subgrains are very obvious. Grain boundaries are

relative straight. Recrystallized grains and remnant detrital grains commonly develop "core and

mantle” structures. The proportion of recrystallized grains is 15-60%. (c) SGR-II, the proportion

of recrystallized grains is 60-90%. In the center of the photo, the relict detrital grain is still

visible. (d) Grain boundary migration recrystallization (GBM) (>500°C). Almost no relict

porphyroclasts can be found. The grain boundaries are lobate and grain contacts are

interfingering. Irregular grain sizes, shapes and boundaries due to the increased grain boundary

migration.

21

2.4.1 Field Observations

2.4.1.1 Tharoch Transect

The transect extends across Deoban Group, Outer LHS, THS/Haimanta rocks which dip

10~30° to the north-northeast, crossing the Tons thrust and MCT from south to north (Figure

2.4). The Tons thrust here is marked by the up section lithological change from the Deoban

Group carbonate to the Outer LHS rocks near the south end of this transect. The thrust contact

itself is not exposed, although it can be determined within ~50 m in the field. Deoban Group

here includes massive bluish grey limestone and pink to greenish grey dolomite. Bedding

thicknesses range from ~30 to ~200 cm. The Tons thrust hanging wall section is ~2 km thick.

From south to north, lithological changes of the Outer LHS are: carbonaceous shale/slate to

medium-size quartzite (30-50 cm) of brown color interbedded with carbonaceous shale/slate

(~400 m), to chlorite phyllite with boudinage quartzite (~1200 m), to quartzite-rich chlorite

phyllite (~400 m). Structural style is distinct across the buried Tons thrust: Folds with

wavelength and amplitude of tens of meters and brittle faults are common in the footwall,

whereas south-southwest-verging, tight to open folds with wavelengths ranging from a few

millimeters to a few meters were commonly observed in the hanging wall Outer LHS rocks

(Figure 2.7A, 2.7B). At north end of this transect, the MCT is a ~800 m thick shear zone (also

see Bhargava, 1976). Quartzite-rich garnet mica schists of Haimanta Group in the upper~600 m

of the shear zone are dominated by top-SW S-C fabrics and sigma-type porphyroclasts (Figure

2.8A). In the lower ~200 m of the shear zone, mylonitized biotite-quartz-schists of the Outer

LHS are characterized by strong foliations and southwest-northeast directed lineations defined

by biotite.

22

Figure 2.7 Field photographs of the Tons, Berinag, and Pabbar thrusts and their hanging wall. (A)

SW verging asymmetric fold of the Outer Lesser Himalayan rock in the Tons hanging wall,

indicating top-to-SW shearing. (B) SWt verging asymmetric folds of the Outer Lesser

Himalayan rock near the Tons thrust, indicating top-to-SW shearing. (C) S-C fabric in the

Berinag quartzite. (D) Deformed quartz veins developed in Berinag quartzite of the Pabbar thrust

footwall, indicating top-to-SW shearing. (E) Sheath fold of the OLH rock, within the Pabbar

thrust zone, with its hinge line parallel with local stretching lineation indicating strong NE-SW

directed shearing. (F) Sheath folds by strongly deformed OLH rock within the Pabbar thrust zone,

with hinges dipping to NE. (G) NE-SW directed stretching lineation of quartz within the Pabbar

thrust zone. (H) The Tons thrust exposed near the structural window along the Pabbar transect. (I)

The Overturned Berinag thrust (the overturned limb of the anticline in cross section B-B’

exposed near the structural window along the Pabbar transect. (J) Asymmetric folds of the

Berinag group near the Berinag thrust, indicating top-to-SW shearing. (K) The Munsiari thrust

exposed in the upper Tons River. (L) slickenfibers on the foliation surface indicating SW

directed brittle thrust within the Munsiari thrust zone (M) Schuppen zone of quartzite within the

Munsiari thrust zone.

23

24

Figure 2.7 continued

25

Figure 2.7 continued

26

2.4.1.2 Lower Pabbar Transect

A ductile shear zone was mapped along this transect, separating Outer LHS hanging wall

above from Berinag Group footwall below. We term this structure the Pabbar thrust. From south

to north, this transect extends across the Berinag thrust, the Pabbar thrust, and a structural

window formed by folding of the Pabbar thrust, the Berinag thrust and the Tons thrust at the

northern end of this transect.

Figure 2.8 Photomicrographs of deformation fabrics associated with the Tons, Berinag and

Pabbar thrusts. All thin sections are cut perpendicular to foliation and parallel to lineation. (A)

Sample HY112311-1: σ-type garnet porphyroclast within the MCT zone along the Tharoch River,

indicating top-to-SW shearing. (B) Sample Yu91118-06 in the footwall of Pabbar thrust: Berinag

quartzite with σ-quartz porphyroclast indicating top-to-SW shearing. (C) Sample HY112811-02

within the Pabbar thrust zone: mylonitized Berinag quartzite bearing feldspar fish with strain

shadow indicating top-to-SWvshearing. (D) Sample HY112611-07 within the Pabbar thrust zone:

mylonite of OLH sequence with S-C fabrics, indicating top-to-SW shearing. (E) Sample

HY112611-05 in the hanging wall of the Pabbar thrust: OLH quartzite with S-C structure shown

by two groups of mica foliations, indicating top-to-SW shearing. (F) Sample HY110312-01

within the Pabbar thrust zone: S-C structure defined by mica foliation-C and deformed quartz-S,

indicating top-to-W shearing.

27

Near the junction of the Tons River and the Pabbar River at southern end of the transect,

the Berinag thrust separates Berinag Group quartzite above from the Deoban Group carbonate

below. The thrust contact itself is buried within a ~600 m gap in exposure. Deoban Group

carbonate is dark-gray limestone with bedding thickness of ~30-50 cm; no foliation is observed.

Berinag quartzite is fine-medium grain, white, and sericitic quartzite with original bedding

thickness of 0.2-2 m. Foliation is defined by chlorite, muscovite, and biotite. Weak northeast-

trending stretching lineations defined by mica were observed in the Berinag quartzite near the

buried contact (Figure 2.4). The Berinag thrust hanging wall section is ~ 2 km thick. S-C fabrics

(Figure 2.7C), deformed quartz veins (Figure 2.7D) and σ-quartz (Figure 2.8B) are pervasive in

the upper ~600 m.

At the northern limit of this Berinag section, the ~450 m ductile shear zone of the Pabbar

thrust separates Outer LHS above from Berinag Group below. In the lower ~300 m of the shear

zone, white and light-green Berinag quartzite with 2-3mm large grains (pinkish/ colorless)

surrounded by ~0.02-0.05 mm fine grains is strongly mylonitized, dominated by Sigma-type

porphyroclasts and S-C fabrics. All observed shear fabrics indicate strong top-to-southwest sense

of motion. The large grains are remnant detrital grains which escaped incomplete dynamic

recrystallization of quartz and feldspar (3-5% of mode) (Figure 2.8C). In the upper ~150 m of the

shear zone, Outer LHS rocks are fine-grain, grey quartzite with original bedding thickness of

~20-30 cm interbedded with dark-grey phyllite. Those rocks are dominated by mylonitic fabrics

(Figure 2.8D) including sheath folds of cm to m scale (Figure 2.7E, 2.7F). Northeast trending

stretching lineations defined by strongly deformed quartz are parallel to the long axes of sheath

folds (Figure 2.4, Figure 2.7G).

28

The Outer LHS rocks immediately overlying the Pabbar shear zone are medium-to-coarse

grained, grey quartzite with foliations defined by biotite and chlorite. S-C fabrics expressed by

two orientations of the mica are common throughout the Pabbar thrust hanging wall section

(Figure 2.8E). The Pabbar thrust hanging wall section is ~3.5 km thick.

Near the northern end of this transect, the Tons thrust, the Pabbar thrust and the Berinag

thrust occur folded in an overturned km-scale anticline, creating a structural window that exposes

Deoban Group carbonate (Figure 2.4). The shear zone of the Pabbar thrust is exposed here again

(Figure 2.8F), intersecting with the Berinag thrust and the Tons thrust near the west termination

of the window. The Tons thrust is exposed in the northern limb of the anticline (Figure 2.7H).

The Outer LHS in the hanging wall is fine-to-medium grained, white /brown quartzite with

foliations and southwest trending stretching lineations defined by mica. Deoban Group in the

footwall includes dark-grey limestone with bedding thickness of 10-30 cm, and no foliation

development. The Berinag thrust is exposed in the southern overturned limb of the anticline

(Figure 2.7I). Berinag Group quartzite near the contact is of brown and dark-green color, with 2-

4 mm large grains (light blue) surrounded by ~0.02-0.05 mm fine grains, and is strongly

mylonitized. Foliation is defined by chlorite and biotite. Northeast trending lineations defined by

mica are common. Deoban Group carbonate in the Berinag thrust footwall here shares the same

lithological and structural features with the Tons thrust footwall. At the east side of the window,

the Pabbar thrust intersects with the MCT.

2.4.1.3 Tons River Transect

This ~35 km long transect extends across Deoban Group, Berinag Group, and Munsiari

Group rocks from southwest to northeast (Figure 2.4, Figure 2.5). These rocks dominantly dip

moderately to the northeast. The structural geometry involves three main elements. First,

29

although the immediate hanging wall of the Berinag thrust consistently comprises the Berinag

Group, the footwall varies from Deoban Group rocks in the southwest to Munsiari Group rocks

in the northeast. Second, the Berinag thrust occurs in both the footwall and hanging wall of the

Munsiari thrust. Third, all structures are warped via open folds.

At the southwest end of this transect, the Berinag thrust places the Berinag group

quartzite atop the Deoban Group carbonate. The thrust contact itself is buried in a ~500 m

covered span. Metamorphic grade and deformation styles exhibited by the Deoban and the

Berinag Group rocks here match observations from the southern end of the Pabbar transect.

Asymmetric folds in the Berinag Group indicate top-to-southwest shear (Figure 2.7J). The

Berinag thrust hanging wall section is about 2 km thick, and is exposed along ~14 km of the

transect. Several km-scale open folds are developed along this transect, resulting in local

exposures of Deoban carbonate.

Farther to the northeast, the Berinag Group rocks are underthrust along the Munsiari

thrust below a package of the Berinag and the Munsiari Group rocks divided by the Berinag

thrust. The southern limits of the Berinag and Munsiari Group rocks in the Munsiari thrust

hanging wall form a fault-cutoff (Figure 2.5). The Berinag Group rocks in the hanging wall

consist of fine-grained, white & light-green quartzite with 1-2 mm large remnant detrital grains,

whereas the Munsiari Group rocks consist of augen gneiss and granitic schist with ~20 cm long

feldspar. The Munsiari Group is exposed as footwall of Berinag thrust and hanging wall of

Munsiari thrust along ~ 20 km of the transect; this Munsiari Group section is ~4 km thick.

The Munsiari thrust is folded in a km-scale syncline-anticline pair, and its footwall

Berinag Group rocks are exposed in the anticline core (Figure 2.5; Figure 2.7K). The Munsiari

thrust is exposed here as a 1–2-km-thick top-to-the-south / top-to-the-south-southwest shear zone.

30

It features S-C mylonitic fabrics in the Munsiari Group rocks which are overprinted by a >50-m-

thick schuppen zone along the Munsiari Group - Berinag Group lithologic contact. The schuppen

zone features south-southwest–directed Riedel shears, cataclasite, and slickenfibers and is

comprised of 2 to15 m thick horses of quartzite and granitic gneiss (Figure 2.7L, 2.7M). Jain and

Anand (1988) report the northernmost exposure of the Berinag thrust just beneath the MCT as a

ductile shear zone which emplaced the Berinag Group atop the Munsiari Group. The thickness of

the Berinag Group there is 300-500 m.

The observed structural repetition of the Berinag thrust along the Munsiari thrust requires

a specific kinematic evolution along the Tons transect. The Berinag thrust developed first,

juxtaposing Berinag Group atop Deoban Group in the southwest and Munsiari Group in the

northeast. Next, out-of-sequence thrusting along the Munsiari thrust repeats the Berinag thrust.

The out-of-sequence thrusting heave is 4-5 km (Figure 2.5). The late warping of all other

structures by open folding is likely due to continued duplexing and/or motion over bends in the

Himalayan sole thrust.

2.4.2 Quartz Microstructures

BLG quartz microstructure dominates in the Tons hanging wall rocks along Tharoch

transect, except for the sample immediately below the MCT, which displays SGR fabrics (Figure

2.9). Other quartzite samples display inhomogeneously flattened detrital grains (0.3-0.8mm) with

very fine recrystallized grains (≤ 0.05mm) locally along grain boundaries. The above observation

indicates that deformation across the Tons thrust hanging wall occurred below ~380°C.

SGR-II quartz microstructure dominates the Berinag, Pabbar, and Tons thrust hanging

walls along the lower Pabbar and Tons river transects (Figure 2.9). GBM recrystallization occurs

only along and immediately above the Pabbar shear zone: here 80-90% of detrital grains were

31

recrystallized. Grain boundaries are lobate and interfingering. These observations indicate that

deformation along the Pabbar thrust hanging wall occurred at >500 °C.

Figure 2.9 Results of quartz recrystallization mechanisms study annotated in the simplified

Local geological map in the Tons valley. Thrust symbols are same in as in the figure 2.2.

2.5 Discussion

Our mapping in the northwestern Indian Himalaya documents a new discovery: a ~ 450

m thick top-to-southwest shear zone, termed the Pabbar thrust, in the NW Indian Himalaya. The

Pabbar thrust placed the Outer Lesser Himalayan Sequence (the Tons thrust hanging wall)

directly on the Berinag Group (the Berinag thrust hanging wall). The shear zone is characterized

by sheath folds, S-C fabrics and mylonitic fabrics, all with top-to-the-southwest shear sense.

Quartz microstructures in the study area indicate that deformation along the Pabbar thrust and its

immediate hanging wall occurred above ~500°C, deformation across most of the Berinag Group

occurred between 400-450 ° C and deformation across most of the Outer LHS occurred below

~380°C. Additional mapping indicates that the Munsiari thrust duplicates the Berinag thrust and

its hanging wall and footwall rocks by out-of-sequence faulting, but the heave of out-of-sequence

32

faulting is limited to ~5km. Below we discuss the kinematic evolution of the Tons thrust, the

Pabbar thrust and the Berinag thrust; along-strike variations in thrust geometries and deformed

stratigraphy; and implications for kinematic evolution of the Himalayan fold-thrust belt.

2.5.1 Kinematic Evolution of the Tons Thrust, Pabbar Thrust and Berinag Thrust

The Pabbar thrust separates the Outer LHS above from the Berinag Group below (Figure

2.4). This map geometry can be accomplished via two kinematic processes: out-of-sequence

faulting of the Pabbar thrust across the Berinag thrust, or accretion of the Berinag thrust sheet to

the Pabber thrust hanging wall (Figure 2.3B). In the first case, the Berinag thrust should slip first.

In this model, the Pabbar thrust and the Tons thrust are a single structure. In the second case, the

Pabbar thrust developed first, followed by accretion of the Berinag sheet. Continued motion

along the new sole thrust toward the foreland becomes the Berinag and Tons thrusts, operating as

a single structure.

Our field mapping documented that mylonitic structural fabrics developed in both

hanging wall and footwall of the Pabbar thrust, whereas foliations developed in hanging wall of

the Berinag thrust and the Tons thrust but not in footwalls of these structures. This distinction

indicates that the Pabbar thrust developed as a ductile shear zone whereas brittle deformation

along the Berinag and Tons thrusts overprints ductile deformation of their hanging wall rocks.

Given the spatial proximity of these structures - e.g., mapping presented in Figure 2.4 documents

their intersection - the brittle overprinting relationship indicates that motion along the Berinag

and Tons thrusts postdates motion along the Pabbar thrust. Quartz microstructure study shows

that deformation across the Pabbar thrust occurred at the higher temperature (> 500°C) than that

across hanging wall of the Berinag (400-500°C) and Tons thrust (< 380°C). Therefore the field

observations and quartz microstructures indicate the Pabbar thrust developed earlier and hotter

33

(i.e., deeper) than the Berinag and Tons thrusts. These findings are inconsistent with an out-of-

sequence evolution, but consistent with duplexing processes. Because the Berinag thrust and the

Tons thrust appear contiguous (Figure 2.4) and move as a single structure in the duplexing model,

we henceforth refer to them as the Berinag-Tons thrust.

The duplexing evolution of the Pabbar thrust and the Berinag-Tons thrust here confirms

the overall dominance of duplexing during the ongoing growth of the Himalayan fold-thrust belt

since the Middle Miocene. Our new interpretation of the kinematic evolution of the Munsiari

thrust also indicates the extent of out-of-sequence faulting along the structure: less than 10 km of

throw, and less than 5 km of heave. Expansion of the orogen by incremental accretion is also

precluded here because the prediction of pervasive shear features through the LHS is not

consistent with field observations. Instead, shear is concentrated within 100-meter-scale fault

zones.

2.5.2 Along-strike Variations of Thrust Geometries and Stratigraphic Correlation

Here we explore the implications of the duplexing evolution along the Pabbar thrust and

Berinag-Tons thrusts for structural variations along the strike of the orogen. We find that along-

strike extension of these kinematics and corresponding geometries is consistent with the

observed orogenic framework and resolves a stratigraphic continuity problem across the India –

west Nepal border, where structures appear continuous but stratigraphy does not match.

Before analyzing specific map patterns, it is useful to consider how minor variations in

the duplexing process could result in changes to structural geometries. In particular, after motion

along the Pabbar thrust, minor differences in Berinag-Tons thrust development could produce a

range of geometries (Figure 2.10). Our mapping indicates that the Berinag-Tons thrust accretes a

new sheet of Berinag Group material to the overriding wedge. If the southern limit of the newly

34

Figure 2.10 Sketched kinematic evolutions of the Pabbar thrust and the Berinag-Tons thrust. (A)

Duplexing of the Pabbar thrust. (B) Duplexing of the Berinag-Tons thrust. Dash lines represent

possible positions of the Berinag Group hanging wall ramp of the Berinag-Tons thrust. (C) Case

①: position of the Berinag Group hanging wall ramp of the Berinag-Tons thrust is south to the

Pabbar thrust and MCT branch line, which explains structural geometries along cross sections a-

a’, d-d’, and e-e’ in Figure 2.11 and Figure 2.12. Case ②: position of the Berinag Group

hanging wall ramp of the Berinag-Tons thrust is very close to the Pabbar thrust and MCT branch

line, which explains structural geometry along cross section b-b’ in Figure 2.11 and Figure 2.12.

Case ③: position of the Berinag Group hanging wall ramp of the Berinag-Tons thrust is north to

the Pabbar thrust and MCT branch line, which explains structural geometry along cross section

c-c’ in Figure 2.11 and Figure 2.12.

accreted Berinag Group material is south of the Pabbar thrust - MCT branch line (Figure 2.10 C-

1), then the juxtaposition of the Outer Lesser Himalaya and the Berinag Group along the ductile

shear zone of the Pabbar thrust will be preserved, as observed in the study area (Figure 2.4).

However, if the southern limit of the newly accreted Berinag Group material is north of the

Pabbar thrust - MCT branch line (Figure 2.10 C-3), then the juxtaposition of the Outer Lesser

35

Himalaya and the Berinag Group along the ductile shear zone of the Pabbar thrust will not

occur.

We note a series of different structural geometries across the western Himalaya that are

consistent with minor variations in the kinematic evolution of the Pabbar thrust and the Berinag-

Tons thrust, as described above. These structural geometries are described via five sketch NE-

SW cross sections located on a simplified tectonic map (Figure 2.11) and displayed in Figure

2.12. Cross sections a-a’, b-b', c-c', and d-d' occur from west to east across the northwestern

Indian Himalaya, and cross section e-e' is in far-western Nepal. Cross section a-a’: the position

of the Berinag Group hanging wall ramp of the Berinag-Tons thrust is south of the Pabbar thrust

- MCT branch line (Figure 2.10 C-1). A large segment of the Pabbar thrust was preserved via the

accretion of the Berinag-Tons thrust sheet. All the structures are wrapped by continue duplexing

process, therefore only small portion of the Pabbar thrust was buried and the rest was eroded

away. In map view, the Outer LHS outcrops are separated from the Berinag Group outcrops by

the footwall rocks (Deoban Group) for ~20 km. Cross section b-b’: the position of the Berinag

Group hanging wall ramp of the Berinag-Tons thrust is very close to the Pabbar thrust - MCT

branch line. Only a small segment of the Pabbar thrust was preserved via the accretion of the

Berinag-Tons thrust sheet (Figure 2.10 C-2). Cross section c-c’: the position of the leading edge

of the Berinag Group is north of the Pabbar thrust - MCT branch line (Figure 2.10 C-3). In this

case, the relationship of the Outer LHS rocks over the Berinag Group which characterizes the

Pabbar thrust does not occur. Locally, MCT hanging wall rocks directly overlie Deoban Group

rocks.

Similar along-strike variations of thrust geometries can also explain an abrupt

stratigraphic change across the India-west Nepal border. In the vicinity of the Almora-

36

Figure 2.11 Sketched regional geological map of the central northwestern Indian and west Nepal

Himalaya from figure 2A annotated with published detrital zircon dating, showing the along

strike lithological variations of the Outer LHS and the Berinag group: exposure of the Outer LHS

is limited to northwest Indian Himalaya, whereas just across the India-West Nepal border, the

Paleoproterozoic Ranimata-Kushma Formation (equivalent of Berinag Group, Table 2.1) is

exposed.

37

38

Dadeldhura klippe of the MCT, Neoproterozoic Outer LHS rocks (~ 800 Ga) dominate the

hanging wall of the Berinag-Tons thrust on the Indian side, whereas Paleoproterozoic rocks

(~1.8 Ga) occur in the same structural position in far-western Nepal (Celerier et al., 2009). Cross

sections d-d’ and e-e’ (Figure 2.11 and Figure 2.12) illustrate how the Pabbar thrust geometry

can resolve this problem. Cross section d-d’: The Berinag Group hanging wall ramp of the

Berinag-Tons thrust is south to the Pabbar thrust - MCT branch line (Figure 2.10 C-1). The

Pabbar thrust remains buried so that only the Outer LHS outcrops in the hanging wall get

exposed south of the Almora-Dadeldhura klippe in map view (Figure 2.11 and Figure 2.12). Just

across the border, the Pabbar thrust hanging wall rocks (the Outer LHS) are eroded away (cross

section e-e’), therefore only the Berinag Group is exposed (Figure 2.11 and Figure 2.12).

2.6 Conclusions

Our work in the northwestern Indian Himalaya advances knowledge about ongoing

Himalayan growth, which is generally thought to be dominated by duplexing and/or extrusion

processes. Duplexing models highlight accretion of material from the subducting plate to the

over-riding orogenic wedge, whereas extrusion models generally focus on southwards translation

of a fault-bounded block towards the surface.

We examined the viability of these models for a region of the Himalaya with rich

stratigraphy across the younger portions of the mountain chain, because rich stratigraphy affords

a high resolution view of deformation. The study region in northwestern India held a key

structural mystery (Webb et al., 2011): three possible geometries could relate two dominant

structures, the Berinag thrust and the Tons thrust. In turn, this set of possible geometries allows a

range of ongoing growth kinematics, such that either duplexing or extrusion could represent the

dominant mountain-building mechanism here since the middle Miocene.

39

Figure 2.12 Serial cross sections showing along strike variations of structural geometries can be

explained by minor variations of kinematic of the Pabbar thrust and the Berinag-Tons thrust.

Positions of those cross sections are marked in Figure 2.11.

40

Our field-based analytical work shows that the Berinag thrust and the Tons thrust are in

fact the same structure. It has long been understood that these faults share the same footwall

rocks (e.g., Valdiya, 1980). A previously unrecognized shear zone, which we term the Pabbar

thrust, separates the distinct hanging wall rocks. The resultant structural framework is consistent

with duplexing processes and limits extrusion to a minor role in mountain-building. These

findings are consistent with results from thermo-kinematic modeling of rich thermochronological

data across the central Nepal Himalaya (Herman et al., 2010). Therefore northwestern India

offers a study region wherein the stratigraphic diversity and structural resolution is sufficiently

rich to allow investigation of the discrete structures which accomplish the accretion process

modeled in a continuum fashion across Nepal. This advantage suggests that this region will

continue to offer key insights as we advance exploration of climate-erosion-tectonic interactions

during collision.

41

CHAPTER 3

KINEMATIC EVOLUTION OF HIMALAYAN OROGEN CONSTRAINED BY

NEW FISSION TRACK ANALYSIS IN NW INDIA

3.1 Introduction

We test kinematic models of Himalayan growth by determining the geometry and

kinematics of key regional structures which deformed the Lesser Himalayan Sequence in

northwest India. In this chapter, we will provide a new set of robust low temperature

thermochronological data across the strike of major thrusts and a line-length balanced

palinspastic reconstruction across the NW Indian Himalaya to further constrain the Himalaya

mountain building process. Our previous work reveals 1) a previously unrecognized shear zone,

which we term the Pabbar thrust, 2) the Berinag thrust and the Tons thrust are in fact the same

structure, which we term the Bering-Tons thrust. The Pabbar thrust placed the Outer Lesser

Himalayan Sequence directly on the Berinag Group, followed by the accretion of Berinag-Tons

thrust sheet. The resulting revised structural framework is consistent with duplexing, and

demonstrates that extrusion accomplishes only minor shortening since the middle Miocene. In

this chapter, we will provide a new set of robust low temperature thermochronological data

across the strike of major thrusts and a line-length balanced palinspastic reconstruction across the

NW Indian Himalaya to further constrain the Himalaya mountain building process.

Previous thermochronological studies in this area and adjacent region mainly focus on the

north portion of the wedge. U-Th monazite-inclusion dating, 40

Ar/39

Ar muscovite cooling ages,

and zircon fission track ages from the GHC along the Sutlej River imply Early to Late Miocene

activity of the MCT in the north (e.g., Schlup, 2003; Vannay et al., 2004; Thiede et al., 2005;

Caddick et al., 2007; Chambers et al., 2008). The 40

Ar/39

Ar muscovite analysis of the Berinag

Group yielded cooling ages between 13.5 to 4.3 Ma and younger ages are proximal to the

42

Munsiari thrust, which is interpreted to be related to the thermal relaxation following

emplacement of the MCT hanging wall: samples near the leading edge of the MCT sheet cooled

earlier than those near the root as a result of the retreat of the white mica closure isotherm toward

thermal equilibrium (Célérier et al., 2009b). Alternatively, these 40

Ar/39

Ar ages indicate initiation

of the Berinag-Tons thrust during Late Miocene and the broad younging age pattern towards the

Munsiari thrust is due to the flat-ramp geometry of the Main Himalayan Thrust. Abundance of

apatite fission track (AFT) ages in the GHC and the Munsiari Group in this area and regions to

the east show < 4 Ma cooling ages indicating a rapid exhumation period (e.g., Bojar et al., 2005;

Patel and Carter, 2009; Patel et al., 2011; Singh et al., 2012).

The incomplete thermal history limits time constraint on the balanced palinspastic

reconstruction. Peak metamorphic temperature of the Outer LHS is indicated under ~330°C

recorded by Raman spectroscopy of carbonaceous material (RSCM) study (Célérier et al.,

2009b), which makes the AFT and zircon fission track (ZFT) dating suitable for the southern part

of the Himalaya. In this chapter, a new set of AFT and ZFT data covering the southern portion of

the Himalaya along the Alaknanda River transect is presented. The yielding results are consistent

with our duplexing concept of the Pabbar thrust and the Berniag-Tons thrust, restrict the Late

Miocene movement of the Berinag-Tons thrust, and place a well constraint on tectonic depth of

Damtha /Deoban Group and the Outer LHS. With the above findings, our balanced palinspastic

reconstruction along the Alaknanda River transect provide vigorous control of kinematic

evolution of the Himalayan wedge.

3.2 Methods: Apatite and Zircon Fission Track Analysis

In order to constrain the deformation history of northwestern Himalaya, 15 samples were

collected along the Alaknanda River transect for apatite and zircon fission track analysis using

43

the external detector method (Naeser, 1979; Wagner and Van den Haute, 1992; Dumitru, 2000).

Samples are evenly distributed along the transect, and across the major thrusts in order to

constrain timing of those thrusts.

Fission track analysis is a useful technique to document low temperature thermal history

during orogeny. Fission track cooling ages represent the elapsed time since rocks cool below an

effective closure temperature of specific mineral (e.g., Price and Walker 1963; Fleischer et al.,

1975; Zeitler et al. 1982; Corrigan 1991; Gallagher 1995; Ketcham et al., 2000; Hodges 2003;

Jonckheere et al., 2003; Donelick et al., 2005; Tagami 2005; Tagami and O’Sullivan 2005;

Reiners and Brandon, 2006; Bernet, 2009). Closure temperature of mineral may change with

regional cooling rates (e.g. Hodges 2003). An effective closure temperature of 135 ± 10°C for

apatite and 240 ± 30 °C for zircon is used in this study (e.g. Bernet et al., 2006; Thiede et al.,

2009).

Apatite and zircon concentrates were prepared by standard crushing, heavy liquid

separation using Bromoform (CHBr3), Methylene Iodide (CH2I2) and magnetic separation.

Fission track analysis was conducted in Geologie, Technische Universitat Bergakademie

Freiberg, Germany.

Apatite grains were mounted in epoxy, ground, and polished. Apatite samples for age

dating were etched for 15s in 23% HNO3 at 25 °C and the muscovite external detectors in 40%

HF for 30 min at room temperature. Pooled ages were determined using the zeta approach,

employing the IRMM-540R uranium glass; Zeta values were calibrated by counting Durango

and Fish-Canyon tuff apatite age standards (Table 3.1). Tracks were counted on prismatic apatite

surfaces with a Zeiss Axioplan microscope in transmitted light. The muscovite external detectors

44

were repositioned, trackside down, on the apatite mounts in the same position during irradiation;

where possible, we counted at least 20 grains of each sample.

Apatite samples for confined track-length measurements were etched for 20s at 21 °C in

5.5N HNO3 (Donelick et al., 1999). All samples were irradiated with heavy ions at GSI

Darmstadt to increase the number of etchable confined tracks (Jonckheere et al., 2007).

Hand-picking zircon grains were mounted in Teflon, ground, and polished. Tracks in

zircon grains were etched in a eutectic mixture of KOH and NaOH at 228 °C for 2–30 hours. We

prepared three mounts (etched for different time) for each sample to guarantee enough grains for

counting. Etched samples were covered with 50 μm thick, uranium-free muscovite external

detectors, and packed between three mounts of uranium glass (IRMM-541). Samples were

irradiated in the hydraulic channel of the FRM-II reactor, Munich, Germany. The muscovite

external detectors were etched in 40% HF for 30 min at room temperature. Pooled fission track

ages are calculated using zeta calibration method (Hurford and Green, 1982, 1983). Zeta values

were calibrated by counting Fish-Canyon tuff zircon age standards irradiated together with

samples (Table 3.1). Tracks were counted on prismatic zircons with a Zeiss Axioplan

microscope in transmitted light; and the corresponding muscovite external detectors were

counted using an Autoscan (Autoscan Systems Pty. Ltd, Australia) system.

45

46

3.3 Results

3.3.1 Fission Track Analysis

Apatite fission track age data were obtained from six samples (the other nine samples

didn’t yield enough apatite grains). Apatite track length data were not obtained since all those

samples only contains zero to several confined tracks. Zircon fission track age results were

obtained from thirteen samples, and pooled ages are reported with 1σ error. Further details on the

age calculation are provided in Appendix A and Appendix B.

Six AFT samples yield cooling ages between 8.4±0.4 and 1.1±0.1 Ma. Analytical results

are shown in Table 3.1 and Figure 3.1. AFT ages show younger trend towards north: the

southernmost sample YU 91129-6 of Early Paleozoic granite gneiss was collected from the MCT

hanging wall in the Lansdowne Klippe, which yields the oldest AFT age of 8.4±0.4 Ma. Sample

YU 91130-6 of sandstone from Berinag-Tons thrust footwall (Damtha/Deoban Group) yields

AFT age of 6.7 ±0.6 Ma. Two samples (YU 91130-9 and YU 91201-9) from Berinag-Tons thrust

hanging wall (Outer LHS) yield AFT ages of 6.2±0.3 Ma and 3.7±0.3 Ma, respectively. Sample

YU 91208-4 of Baragoan augen gneiss within the MCT zone in Baijnath Nappe yields AFT age

of 4.0±0.3 Ma. Sample YU 91206-1 of granite gneiss from Munsiari Group in the hanging wall

of Munsiari thrust yields the youngest age of 1.1±0.1 Ma.

ZFT ages were obtained from 13 samples (Table 3.1). The southernmost sample YU

91129-1 of Outer LHS immediately in the Krol thrust hanging wall yields multiple age groups

ranging between 34.0±7.5 to 554.5±126 Ma (Figure 3.2A). Three samples of Damtha/Deoban

Group in the footwall of Berinag-Tons thrust also yield multiple ZFT age groups: Sample YU

91130-2 yields age ranging between 76.9±11.0 to 315.1±45.9 Ma (Figure 3.2B), sample YU

47

Figure 3.1 (A) Zircon fission track and Apatite fission track data annotated in regional

geological map of the central northwestern Indian and west Nepal Himalaya. Number of red

color represents zircon fission track age. Number of dark blue color represents apatite fission

track age. In this map the Berinag thrust and the Tons thrust is marked by the same fault symbol

because our work shows that they are in fact a same structure. The Damtha Group and Deoban

Group are treated as one unit for our restoration purpose (see discussion in the text). See other

notes as in Figure 2 in Chapter 2. (B) Fission track ages are plotted against distance to the Krol

thrust. Solid symbols are from this study, whereas empty symbols are from Pater and Carter

(2009). Pink color symbols represent zircon fission track data. Blue color symbols represent

apatite fission track data. (C) Cross section A-A’: dash lines with arrows point to positions of

samples in cross section. Pink color stars on dash lines represent samples with non-reset zircon

fission track ages. Abbreviations: MCT-Main Central Thrust, STD-South Tibet Detachment.

48

49

91130-6 yields similar age groups ranging between 23.2±2.8 to 440±144.4 Ma (Figure 3.2C),

and Sample YU 91204-9 yields age groups ranging from 14.0±2.4 to 423.2±60.1 Ma (Figure

3.2D). ZFT samples with a single age group also show a generally younger pattern towards north

(Table 3.1 and Figure 3.1). ZFT ages range between 26.8±1.9 and 28.8±1.8 Ma for two samples

in the hanging wall of MCT in the Lansdowne Klippe. Four Outer LHS samples in the hanging

wall of Berinag-Tons thrust yield ages between 12.5±0.4 to 4.7±0.3 Ma from south to north.

Sample YU 91209-1 of Berinag quartzite in the Berinag-Tons thrust hanging wall yields age of

6.7±0.6 Ma. Sample YU 91208-4 of Baragoan augen gneiss within the MCT zone in the Baijnath

Nappe yields ZFT age of 6.0±0.5 Ma. Sample YU 91206-1 of granite gneiss from Munsiari

Group in the hanging wall of Munsiari thrust yields the youngest ZFT age of 1.5±0.1 Ma.

3.3.2 Interpretation

The southernmost sample YU 91129-1 was collected just above the Krol thrust from the

Outer LHS. The majority of ZFT age groups of this sample are older than the collision age (~50

Ma), and younger than its sedimentation age (Neoproterozoic–Cambrian), which are interpreted

to reflect pre-collision tectonic history (Figure 3.2A). This non-reset ZFT age indicates the

maximum tectonic burial depth of the leading edge of Outer LHS in the south does not exceed

ZFT closure temperature isotherm (240±30°C, ~8km assuming a geothermal gradient of

~30 °C/km) before the collision. All samples of the Outer LHS towards north yield reset ZFT

ages, which indicate the tectonic burial depth of Outer LHS in the north is deeper and hotter than

the ZFT closure temperature isotherm (240±30°C, ~8km). The whole Damtha/Deoban Group

(two samples in the south, one sample in the north) yield non-reset ZFT ages, but reset AFT

(sample YU 91130-6) providing robust control on the tectonic burial depth of Damtha/Deoban

50

Group between AFT closure temperature isotherm (135±10°C, ~4km) and ZFT closure

temperature isotherm (240±30°C, ~8km).

Figure 3.1B shows Fission track ages plotted against distance to the Krol thrust. The

southernmost five AFT ages show nearly linear trend with distance without apparent offsets

across the MCT and the Berning-Tons thrust, which indicate 1) the MCT hanging wall rocks and

the Berinag-Tons thrust hanging wall rocks behaved as a single tectonic unit during Late

Miocene cooling. 2) The Berinag-Tons thrust in the Lansdowne Klippe ceased motion in Late

Miocene by ~7 Ma. Youngest AFT age of 1.1±0.1 Ma (Sample YU 91206-1) in the hanging wall

of Munsiari thrust to the north is constant with published young AFT data in the same area (Patel

and Carter, 2009) and along the arc (e.g., Jain et al., 2000; Thiede et al., 2004, 2005, 2009; Patel

et al., 2007; Patel and Carter, 2009), which represent a rapid uplift zone.

Figure 3.2 Radial plot of non-reset zircon fission track data.

51

The Bering-Tons thrust must be active during Late Miocene (~13 Ma) since the whole

Berinag-Tons thrust hanging wall rocks in the north of Lansdowne Klippe yield Late Miocence

ZFT ages (12.5±0.4 to 4.7±0.3 Ma) atop the Damtha Group with non-reset ZFT ages. Therefore

the Berinag-Tons thrust hanging wall sheet must have cooled to the north of the Damtha Group

in Late Miocene and concurrently/subsequently been emplaced. The abrupt change of ZFT ages

(28.8±1.8 to 26.8±1.8 Ma) from the MCT hanging wall in Lansdowne Klippe to ZFT age of

12.5±0.4 Ma from the Outer LHS is probably due to accretion of the Berinag-Tons thrust sheet.

The old ZFT ages in the MCT hanging wall in Lansdowne Klippe are probably link to initiation

of the MCT and emplacement of THS/GHC in Late Oligocene/ Early Miocene.

Both AFT ages and ZFT ages show younger trend towards north, and comparing age

differences between ZFT and AFT of each sample indicates relatively slower cooling rate across

the southern Berinag-Tons thrust sheet. The above pattern is consistent with the Flat-ramp

geometry of the Main Himalayan Thrust derived from geophysics data (e.g., Hetenyi, et al., 2006;

Rai et al., 2006; Nabelek et al., 2009; Acton et al., 2010; Chamoli et al., 2011; Caldwell et al.,

2013), geodetic data (e.g., Pandey et al., 1995; Avouac, 2003, 2007; Berger et al., 2004), and

structural reconstruction (e.g., Schelling and Arita,1991; DeCelles et al., 2001; Pearson and

DeCelles, 2005; Robinson et al., 2006; McQuarrie et al.,2008; Célérier et al., 2009a; Webb et al.,

2011a; Webb 2013).

3.4 Balanced Palinspastic Reconstruction Across the NW Indian Himalaya

Our field-based analytical work along the Tons Valley in Chapter 2 indicates the overall

dominance of duplexing process during ongoing growth of the Himalayan fold-thrust belt since

the Middle Miocene, and provides strong control on kinematic evolution of major thrusts and

along strike changes of structural geometry and stratigraphy. Our new AFT and ZFT data here

52

offer robust constraint on the pre-collision stratigraphic framework and timing of major thrusts

activity of Northern India.

To assess the Cenozoic kinematic history, a balanced palinspastic reconstruction of the

studied segment of the Himalayan arc was made, which extends from the Sub-Himalayan

Sequence, across the LHS, and into the THS fold-thrust belt (Plate 1). Restored time steps were

constructed by progressively “undeforming” the deformed section using a combination of 2D

Move software (Midland Valley) and Adobe Illustrator. Layer parallel simple shear was applied

to unfold fold limbs. Geometry of the Main Himalayan Thrust is approximately consistent with

the latest seismic receiver-function results: flat-ramp-flat (Caldwell et al., 2013). The upper flat

is ~4 km below sea level connecting to a mid-crustal ramp dipping at ~16°. The lower flat is ~15

km below sea level. Deformation across the Sub-Himalayan Sequence and THS was simplified

(Powers et al., 1998). Approximate periods of five restored time steps are 28 Ma, 20 Ma, 13 Ma,

8.1 Ma and 5.2 Ma. All time estimates were determined by measuring shortening distance and

using the geodetic shortening rate of 13.6 mm/yr (Styron et al., 2011) to calculate an age. Ages

assigned to time-steps A (28 Ma), C (13 Ma), D (8.1 Ma), and E (5.2 Ma) are also consistent

with our AFT and ZFT data sets discussed above.

A “pinch-out” model for the pre-collision stratigraphic framework is adopted in this study

(Webb et al., 2011a; Webb 2013): 1) Damtha and Deoban Group, the Outer LHS, the THS were

stacked and tilted to northeast, and all of them were exposed to surface before the collision since

these units are overlain by Late Cretaceous and early Cenozoic rocks locally (e.g., Valdiya, 1980;

Célérier et al., 2009a); 2) the Paleoproterozoic–Neoproterozoic Damtha and Deoban Group

represent the southernmost shallow units pinching out towards northeast, whereas, the

Neoproterozoic–Cambrian Outer LHS represent deeper unit pinching out to the southwest; 3)

53

the Haimanta Group of THS, Greater Himalayan Crystalline complex, and Shimla Group of

Outer LHS represent deformed parts of a formerly continuous unit; 4) the Baragaon granitic

gneiss and Munsiari Group are the oldest deformed units, representing the base of the pre-

collision stratigraphic framework. In our restoration, the Damtha and Deoban Group are treated

as one unit instead of simply overlaying the Deoban Group on the Damtha Group. The internal

deformation of Damtha and Deoban Group is complex (e.g., Webb et al., 2011a; Webb 2013),

and simple overlay relationship can’t explain the map pattern, e.g., immediately north of the

Lansdowne Klippe, only Damtha Group crops out without exposure of Deoban ; alternatively,

the Damtha Group exposed there might be the Mandhali Formation of the Deoban Group. The

pinch-out model is consistent with our new AFT and ZFT data. Non-reset ZFT ages and reset

AFT ages imply the maximum depth of Damtha/Deoban Group does not exceed ~8 km (ZFT

closure temperature isotherm). Non-reset ZFT age from the leading edge of the Outer LHS and

reset ZFT ages in the northern part indicates depth of southernmost Outer LHS is less than ~8

km, but the Outer LHS to the north is deeper than ~8 km. The reset ZFT ages of THS in

Lansdowne Klippe means the burial depth of THS before the collision is deeper than ~8 km.

Therefore, the Outer LHS and THS represent a far-traveled thrust sheet relative to the Deoban

and Damtha Groups along the Berinag-Tons thrust and MCT, respectively. The discovery of the

Pabbar thrust indicates the Outer LHS is further north than the Berinag Group. Our AFT and

ZFT data validate the concept that younger rocks originated at equal and greater depth in the

northeast compared with older rocks in the southwest (Webb et al., 2011a; Webb 2013). This

reconstruction of relative pre-collision structural positions explains thrusting of younger rocks

atop older rocks in the Himachal Himalaya, e.g., the southern portions of the Berinag-Tons thrust

and the MCT place Neoproterozoic rocks atop Mesoproterozoic and/or Paleoproterozoic rocks.

54

3.4.1 Restoration ca. 28 Ma

The reconstruction progresses from the period before the initiation of the MCT around

Late Oligocene (Plate 1A). Imbricate stacking in the THS fold-thrust belt before 28 Ma is not

drawn here (e.g., Wiesmayr and Grasemann, 2002). Most of the units were still deeply buried at

this time, such as the GHC, the LHS. Dashed red lines shown across the restored geometry

highlight fault traces that were active in next step.

3.4.2 Restoration ca. 20 Ma

Deformation during 28-20 Ma time interval is dominated by the emplacement of the

Main Central thrust sheet (Plate 1B). Tectonic wedging of the GHC occurred between the STD

as backthrusting and the MCT. The THS are thrust over the Outer LHS. Two discontinuous thin

slivers of the Baragaon gneiss are interpreted to slide together with the THS along the MCT

since discontinuous slivers of the Baragaon gneiss occur within the Main Central thrust shear

zone in outcrops (Figure 3.1). The emplacement of the Main Central thrust sheet and tectonic

wedging of the GHC require ~108 km of shortening. Thermochronological data across the

southern portion of the line of section is used to infer the position of the ground surface at this

time. ZFT ages range between 26.8±1.9 and 28.8±1.8 Ma for the southern portion of the THS

indicate the THS was above the ZFT closure temperature isotherm at this time. Units that remain

deeply buried at this time include the leading edge of the GHC, the Baragaon gneiss, the central

portion of THS, and The LHS. Solid red lines shown represent reactivation along previous fault

traces in next step. Thick solid black lines represent non-active faults.

3.4.3 Restoration ca. 13 Ma

The ongoing growth during 20-13 Ma period is continued by accretion of the Pabbar

thrust sheet, which emplaced the Outer LHS rocks over the Berinag Group and the

55

Deoban/Damtha Group (Plate 1C). Part of the Deoban and Damtha rocks and small portion of

the Berinag Group is inferred to be transported together with the Outer LHS along the Pabbar

thrust towards the foreland. The GHC, the THS and the Baragaon gneiss were also translated to

the southwest and thrust over the Berinag Group due to initiation of the Pabbar thrust. The

estimate total shortening accomplished during this period is ~95 km. Note that the pre-

deformation traces of the Berinag-Tons thrust slice through the Baragaon gneiss. Therefore, a

discontinuous sliver of the Baragaon gneiss is interpreted to slide along the Berinag-Tons thrust

since discontinuous thin fragments of the Baragaon gneiss occur along the Berinag-Tons thrust

in map (Figure 3.1).

3.4.4 Restoration ca. 8.1 Ma

The Berinag-Tons thrust hanging wall was accreted to the Pabbar thrust sheet during 13-

8.4 Ma time interval, and the Berinag, Outer LHS rocks, and a thin fragment of the Baragaon

gneiss were translated farther south atop of the Deoban and Damtha Groups (Plate 1D). The

hangingwall cutoff of Deoban/Damtha rocks, the Beriang Group and the Sub-Himalaya rocks are

interpreted to be completely eroded away by ca. 8.1Ma. Only a small portion of the Pabbar thrust

was preserved after movement of the Berinag-Tons thrust. The GHC was still deeply buried at

this time. The Late Miocene ZFT ages of the Berinag-Tons thrust Hanging wall rocks are used to

infer the ground surface. The estimate total shortening accomplished along the Berinag-Tons

thrust is ~67 km.

3.4.5 Restoration ca. 5.2 Ma

Continued mountain building is accomplished by the accretion of horses of the Deoban

/Damtha Group and of Munsiari Group (Plate 1E, 1F). Growth since the late Miocene continues

via duplexing of the Deoban and Damtha Groups, antiformal stacking of the Munsiari Group,

56

out-of-sequence faulting along the Munsiari thrust, and frontal accretion of the sub-Himalaya.

Frontal accretion of sub-Himalayan rocks is presumably ongoing throughout the whole

construction of the Himalaya, but only the most recently deformed portions of this unit are

preserved. The hanging wall rocks of the Berinag-Tons thrust, the Pabbar thrust, and MCT have

been passively warped and transferred towards the foreland by late accretion. Duplexing of three

horses of the Deoban/Damtha Group were developed first during 8.1-5.2 Ma. Followed by the

antiformal stacking of four thrust horses of Munsiari Group and continue duplexing of six horses

of the Deoban/Damtha Group. The Munisar Group and GHC were exposed after ~5.2 Ma. This

is good match with thermochronological results that abundance of AFT ages in the Munsiari

Group and the GHC show < 4 Ma cooling ages. Out-of-sequence thrusting of the Munsiari thrust

occurred late and only accommodated ~3 km heave and ~10 km throw.

3.5 Discussion: Extrusion vs. Duplexing Models of Himalayan Mountain Building

The deformation history of Himalayan mountain building involves the emplacement of

THS/GHS, and followed by the ongoing growth dominated by the deformation of LHS.

Currently models for both stages can be divided in two categories: extrusion vs. duplexing.

Extrusion models for the emplacement of THS/GHS emplacement include: 1) the wedge

extrusion models (e.g. Burchfiel and Royden, 1985), and 2) channel flow model (e.g., Nelson et

al., 1996; Beaumont et al., 2001). Extrusion models describe emplacement of GHC as southward

extrusion of a fault-bound block, with the MCT below and the STD above as a normal fault.

Extrusion models predict 1) the MCT and STD are largely subparallel or merge downdip to the

north; 2) exposure of the GHC and THS in the north is required to happen during the main

motion along the MCT and STD in the Early and Middle Miocene. Duplexing models include

the tectonic wedging model which describe emplacement of GHC as accretion of the MCT sheet

57

with STD acting as a sub-horizontal backthrust off of the MCT synchronously (e.g., Yin 2006;

Webb et al., 2007). Duplexing model predicts 1) the MCT and STD merge updip to the south; 2)

exposure of the GHC and THS in the north is post the STD activity during Middle to Late

Miocence to Pliocene. The MCT-STD branch line concept is introduced by the duplexing model.

North of the MCT-STD branch line, the hanging wall rocks of the MCT is the GHC; whereas,

south of the MCT-STD branch line, the hanging wall rocks of the MCT is the THS (Haimanta

Group, which share similar protoliths, ages, metamorphic grade with the GHC) (Webb et al.,

2011a, 2011b). Recent structural geology investigation in northwest Indian Himalaya and Nepal

Himalaya describe the existence of the MCT-STD branch line (Webb et al., 2011a, 2011b; He et

al., 2014 in review).

Extrusion models for the ongoing growth of the Himalayan orogeny generally focus on

southwards translation of a fault-bound block towards the surface, with an out-of-sequence thrust

below (Munsiari thrust), and normal fault above (STD). Duplexing models highlight accretion of

material from the subducting plate to the over-riding orogenic wedge with only minor out-of-

sequence deformation (e.g., Schelling and Arita, 1991; Robinson et al., 2003, Bollinger et al.,

2004; Konstantinovskaia and Malavieille, 2005; Herman et al., 2010, Grandin et al., 2012).

Duplexing may occur through any or all of three processes: frontal accretion involving forward

propagation of the frontal thrust (e.g., Schelling and Arita, 1991), expansion of the orogen via

incremental accretion along the basal shear zone (e.g., Searle et al., 2008), and discrete accretion

of km-to-10 km-scale thrust horses along ramps of the Himalayan sole thrust (e.g., Robinson et

al., 2003; Bollinger et al., 2004; Robinson, 2008; Webb, 2013). Our field-based and analytical

work in Chapter two resolves the kinematic evolution of Pabbar thrust and Berinag-Tons thrust.

The resultant structural framework is consistent with duplexing processes and limits extrusion to

58

a minor role in mountain-building. Our low temperature thermochronology data places well

constraint on the Late Miocene activation of the Berinag-Tons thrust. These findings are

consistent with results from thermo-kinematic modeling of rich thermochronological data across

the central Nepal Himalaya (Herman et al., 2010). Balanced palinspastic reconstruction across

the NW Indian Himalaya also confirms the overall dominance of duplexing process.

3.6 Conclusions

The new set of thermochronological data place robust time constraint on Himalayan

mountain building process: 12.5±0.4 to 6.5±0.5 Ma zircon fission track ages of the Berinag-Tons

thrust hanging wall rocks; 26.8±1.8 to 28.8 ±1.8 Ma zircon fission track ages of the

southernmost exposure of the THS in the hanging wall of the MCT. A balanced palinspastic

reconstruction across the northwestern Indian Himalaya reveals ~380km (66%) shortening along

the MCT, the STD and deformation of the LHS. The Mountain building process includes 1) Late

Oligocene–Middle Miocene emplacement of the GHC, and juxtaposing of the THS atop LHS. 2)

Middle–Late Miocene accretion of the Pabbar thrust sheet and the Berinag-Tons thrust sheet and

3) subsequent growth via a hinterland-dipping upper crustal duplexing and an antiformal stack of

mid-crustal horses developed simultaneously. The kinematic relationship of the Pabbar thrust

and the Berinag-Tons thrust, and our palinspastic reconstruction demonstrate that discrete

duplexing processes dominated ongoing growth of the northwest Indian Himalaya and limited

extent of out-of-sequence faulting (<3% of shortening).

59

CHAPTER 4

KINEMATIC TRISHEAR MODEL OF FAULT-PROPAGATION FOLDING TO

PREDICT DEFORMATION BANDS, COLORADO NATIONAL MONUMENT,

NW UNCOMPAHGRE UPLIFT, USA

4.1 Introduction

The objective of this study is to explore a quantitative method to describe and predict

distribution and orientation of deformation bands related to reverse faulting. The correlation may

have significant implications with regard to better constrain the fluid pathways around faults

because of the potential effect on fluid flow of deformation bands (e.g. Pitman, 1981; Jamison

and Stearns, 1982; Gabrielsen and Koestler, 1987; Antonellini and Aydin, 1994, 1995; Beach et

al., 1997; Crawford, 1998 ; Gibson, 1998; Antonellini et al., 1999; Heynekamp et al., 1999;

Hesthammer and Fossen, 2000; Taylor and Pollard, 2000; Lothe et al., 2002; Ngwenya et al.,

2003; Shipton et al., 2002, 2005; Sternlof et al., 2004; 2005; Flodin et al., 2005; Fossen and Bale,

2007; Wibberley et al., 2007; Torabi and Fossen, 2009; Ballas et al., 2012, 2013). The

Uncompahgre uplift in Colorado plateau is an ideal locality because this region has key

advantages. First, classic deformation bands developed in Late Triassic to Early Jurassic eolian

Wingate Sandstone associated with basement-cored monocline growth. Second, characterization

of those deformation bands including types, density, orientation, thickness and petrophysical

properties are fully documented in published data (e.g. Jamison, 1979; Jamison and Stearns,

1982; Jamison, 1989 ). Third, sufficient surface structural data allow us to better constrain

geometries of the target faults (Scott et al., 2001).

The Uncompahgre uplift was formed due to the Late Cretaceous to Middle Eocene (~70-

50 Ma) Laramide Orogeny by reactivation of inherited high-angle Precambrian basement faults

at depth (e.g., Kelly, 1955; Cashion, 1973; Stone, 1977; Davis, 1978; Davis, 1999; Tindall and

60

Davis, 1999; Bump and Davis, 2003; Bump, 2004; Timmons et al., 2007). The traditional kink-

band based fault-propagation folding featured by angular fold hinges, uniform dips and constant

thickness of fold limbs failed to explain inclined Precambrian basement-Mesozoic rock contact,

curved fold hinges and thickening and thinning of fold limbs (e.g., Suppe, 1983; Suppe and

Medwedeff, 1990). Trishear provides an alternative model of fault-propagation folding

characterized by heterogeneous strain generated by inclined shear in a triangular zone above the

fault tip, which commonly exhibits curved hinges, broad crested anticlines, non-uniform dips,

and changing thickness of fold limbs.

Deformation bands are brittle microfaults with tiny shear offset on the scale of millimeter

to centimeter without clearly defined slip surface, a few millimeters thick and a few meters to

tens of meters long (Aydin, 1978; Aydin and Johnson, 1978, 1983; Antonellini et al., 1994;

Mollema and Antonellini, 1996; Fossen and Hesthammer, 1997; Fossen et al., 2007). They are

usually developed in deformed porous sandstones and sediments (e.g., Jamison and Stearns,

1982; Fisher and Knipe, 2001; Antonellini et al., 1994; Cashman & Cashman, 2000; Hooke and

Iverson, 1995; Hesthammer and Fossen, 1999; Wennberg et al., 2013). Deformation bands are

formed due to strain localization, which may involve granular flow (grain boundary sliding,

rotation, translation), cataclasis (grain crushing, frictional sliding), phyllosilicate smearing,

dissolution and cementation (e.g., Aydin, 1978, Fossen et al., 2007). They may occur naturally as

single bands, deformation band clusters, and slip surfaces at the edge of deformation band

clusters. Deformation bands can be classified into two categories: shear bands with dominant

shear component, compaction bands with pure compaction (volume decrease) or dilation

(volume increase) with no evidence of shear (e.g. Issen and Rudnicki, 2000; Bésuelle, 2001;

Aydin et al. 2006; Chemenda et al., 2011).

61

Deformation bands have drawn attention to geologist and petrologist since 1980s because

of their relatively low permeability compared to the host rocks and their potential role as barriers

to fluid flow. They are found in a large range of geological settings: the Late Triassic to Early

Jurassic eolian sandstones of southwestern USA related to both normal and reverse faulting

events (e.g., Jamison and Stearns, 1982; Jamison, 1989; Mollema and Antonellini, 1996; Davis,

1999; Davis et al., 1999; Shipton and Cowie, 2001; Eichhubl et al., 2004; Katz et al., 2004;

Schultz, 2009; Schultz et al., 2010; Solum et al., 2010; Brandenburg et al., 2012); the pre-rift

sandstones related to normal faulting during rifting in Suez Rift (e.g., Beach et al., 1999; Bernard

et al., 2002; Rotevatn et al., 2008); the continental shelf sandstones related to extension and

inversion structures (e.g., Fisher and Knipe, 2001; Hesthammer et al., 2002; Lothe et al. 2002 );

the unconsolidated, glaciolacustrine delta sands (e.g., Brandes and Tanner, 2012) and Marine

terrace sediment (e.g., Cashman and Cashman, 2000). A lot of research focuses on the laboratory

experimental investigation and numerical modelling on deformation mechanism and

corresponding petrophysical properties of deformation bands (e.g., Wong et al., 1997; Bésuelle,

2001; Borja and Aydin, 2004; Chemenda, 2007, 2009; Wang et al., 2008; Charalampidou et al.,

2011, 2012; Klimczak et al., 2011; Cilona et al., 2012; Chemenda et al., 2012). The above

research indicates: 1) most observed deformation bands show one to six orders of magnitude

reduction in permeability compared to their host rocks. Their practical influence on flow path

may related to deformation mechanism , thickness, connectivity, and three dimension extension

of deformation bands (e.g., Knott, 1993; Main et al., 2000; Jourde et al., 2002; Lothe et al., 2002;

Fossen, 2007; Fossen and Bale, 2007; Olierook et al., 2014; Saillet and Wibberley, 2013). 2)

Density and distribution of deformation bands have direct relationship with fault displacement

and corresponding strain accumulation (e.g., Solum et al., 2010; Brandenburg et al., 2012;

62

Schueller et al., 2013; Soliva et al., 2013; Ballas et al., 2014), however, a clearly quantitative

relationship between distribution of deformation bands and kinematic evolution of fault

development is still uncertain and needs further investigation.

The kinematic trishear model of fault-propagation folding has been used to simulate

monocline growth associated with high-angle reverse faults in the Colorado Plateau (e.g., Erslev

and Selvig, 1997; Cristallini and Allmendinger, 2001; Bump, 2003; Cristallini et al., 2004;

Brandenburg et al., 2012). In this study, trishear model is used to reconstruct the basement-cored

monocline growth in Uncompahgre uplift along three balanced cross sections. The best-fit

parameters are determined for fault movement from reconstruction, which are used later for

forward modeling strain in fault tip zone. The modelling strain result demonstrates excellent

agreement with the strain calculated from deformation bands, and the distribution and orientation

of deformation bands in the field.

4.2 Geology Background

The Uncompahgre uplift, one of several NW-SE trending anticlines in the Colorado

plateau, extends from western Colorado into easternmost Utah. The Colorado National

Monument (CNM) is located on the northeast edge of the Uncompahgre uplift, which is defined

by the basement-cored monocline (Figure 4.1).

4.2.1 Tectonic History of the Uncompahgre Uplift

This area experienced complex tectonic history. First, Proterozoic extension events

generated the basement-penetrating normal faults (e.g., Marshak and Paulsen, 1996; Karlstrom

and Humphreys, 1998; Marshak et al., 2000; Timmons et al., 2001; Whitmeyer and Karlstrom,

2007). The plateau was then exposed to erosion until Cambrian. Throughout the plateau,

extensive erosion stripped away kilometers of metamorphic rocks and exposed high grade

63

Figure 4.1 Geological map of the Uncompahgre Uplift, NW of Colorado National Monument.

This map is simplified from the Geological map of public resource of U.S. Geological Survey

(Geological Investigations Series I-2740).

metamorphic cores, and the hiatus is known as the Great Uncomformity (e.g., Foos et al., 1999;

Scott et al., 2001). The second tectonic event that affected the Colorado plateau is the Late

Paleozoic Ancestral Rockies event (320-245 Ma), related to collisional orogeny along North

America’s eastern and southern margins (e.g., Kluth and Coney, 1981; Bird,1988; Ye et al.,

1996). The Ancestral Rockies event created a series of basins and basement-core uplifts (e.g.,

Kluth and Coney, 1981; Bally et al., 1989; Ye et al., 1996). Those basement-core uplifts are

indicated to be exhumed by reactivation along high-angle normal faults inherited in Proterozoic

basement (e.g., Marshak et al., 2000). The Ancestral Uncompahgre Highlands is one of those

64

northwest-southeast trending basement-cored uplifts, bounded on the southwest by the Paradox

basin and on the northeast by the Central Colorado trough (e.g., White and Jacobson, 1983;

Kluth and DuChene, 2009). Following exhumation, the Precambrian crystalline rocks and the

Lower Paleozoic marine units were exposed to erosion on uplifts and were transported to

adjacent basins. Those uplifts were eventually worn down to a level plain to receive Mesozoic

sediments on Precambrian crystalline basement throughout late Triassic to Late Cretaceous.

During the Late Cretaceous to middle Eocene (~70-50 Ma), the plateau was subject to

another mountain building event-Laramide Orogeny, which is the response to the stress

generated by plate convergence along the west coast of North America (e.g., Stone, 1977;

Brewer et al., 1982; Engebretson et al., 1985; Cross, 1986; Dickinson et al., 1988; Hamilton,

1988; Livaccari, 1991; Burchfiel et al., 1992; Cowan and Bruhn, 1992; Miller et al., 1992;

Monger and Nokleberg, 1996; Davis, 1999; Bump and Davis, 2003; Conner and Harrison, 2003;

English et al., 2003; Bump, 2004; DeCelles, 2004; Erslev, 2005; Erslev and Larson, 2006).

Laramide Orogeny created a series of highly asymmetrical, fault-cored anticlines like the Kaibab,

Monument, Uncompahgre uplifts etc. (e.g., Cashion, 1973; Powell, 1973; Stone, 1977; Davis,

1978; Dutton, 1982; Davis, 1999; Tindall and Davis, 1999; Bump and Davis, 2003; Bump, 2004;

Timmons et al., 2007). They were formed by reactivation of inherited Precambrian basement

faults (e.g., Stearns and Jamison, 1977; Brewer et al., 1982; Allmendinger et al., 1982; Heyman,

1983; Heyman et al., 1986; Brown, 1988, 1993; Blackstone, 1993; Huntoon, 1993; Schmidt et al.,

1993; Foos, 1999; Marshak et al., 2000; Erslev et al., 2001; Bump and Davis, 2003; Bump, 2004;

Erslev and Koenig, 2009; Brandenburg et al., 2012). Both the northeast and southwest flank of

the Uncompahgre lift are featured by the basement-cored monoclines (e.g., Stearns and Jamison,

1977; Stone, 1977; Jamison, 1979; Jamison and Stearns, 1982; Heyman, 1983; White and

65

Jacobson, 1983; Heyman et al., 1986; foos, 1999; Scott et al., 2001). Those basement-cored

monoclines are thought to be developed by fault-propagation folding (e.g., Erslev, 1991; Erslev

and Rogers, 1993; Kellogg et al., 1995; Erslev and Selvig, 1997; Tindall and Davis, 1999;

Brandenburg et al., 2012). Modern topography in the Colorado Plateau is the interaction result

between Post-Laramide regional uplift and river erosion, which is still active in present day (e.g.,

Steven et al., 1997; McMillan et al., 2006)

4.2.2 Major Stratigraphy

The exposed lithology packages in the CNM include Precambrian crystalline rocks,

Mesozoic sedimentary rocks, and Quaternary non-marine deposits (Figure 4.1). The Precambrian

basement rocks are composed of Early Proterozoic dark schist and light migmatitic pegmatite,

granite gneiss, and Middle Proterozoic dikes (see Scott et al., 2001 for detail lithology

description).

The Precambrian basement is overlain directly by the Late Triassic Chinle Formation

dominated by distinctive red colored mudstone deposited in flood plain environment (e.g., Foos,

1999; Scott et al., 2001). The Chinle Formation is of ~30m thickness, which is overlain by Late

Triassic and Early Jurassic sandstone: the porous, cliff-forming Wingate Sandstone with

thickness of ~100 m and thin layer of resistant, silica-cemented Kayenta Formation with

thickness of ~15 m (e.g., Foos, 1999; Scott et al., 2001). The well-sorted, fine-grained Wingate

sandstone is of high porosity (Ø= ~23%) and high permeability (e.g., Jamison, 1979). Eolian

sandstones from the Colorado Plateau attract much attention because of their classic deformation

bands development (e.g., Jamison and Stearns, 1982; Jamison, 1989; Mollema and Antonellini,

1996; Davis, 1999; Davis et al., 1999; Shipton and Cowie, 2001; Eichhubl et al., 2004; Katz et

al., 2004; Schultz, 2009; Schultz et al., 2010; Solum et al., 2010; Brandenburg et al., 2012). The

66

most spectacular primary sedimentary feature of the reddish eolian Wingate Sandstone is the

enormous cross-bedding, which can be used as markers for measuring offsets of deformation

bands. The upper part of Kayenta Formation is eroded away in this area (e.g. Foos, 1999), which

is overlain by lower Middle Jurassic sandstone (~50 m), and mudstone rocks of upper Middle

Jurassic (~15 m), Upper Jurassic (~220 m) and Cretaceous (~1300 m) (e.g., Dunham, 1962;

Pipiringos and O’Sullivan, 1978; Kocurek and Dott, 1983; Peterson, 1988; Aubrey, 1998;

Peterson and Turner, 1998). Due to the Laramide Orogeny, this area became structurally high

again and only received the Quaternary non-marine deposits on regional unconformity above the

Late Cretaceous rocks (e.g., Chapin and Cather, 1983; Cole and Moore, 1994; Scott et al., 2001).

4.2.3 Major Faults in CNM, Uncompahgre Uplift

The Uncompahgre Uplift is bounded by high-angle reverse faults along both northeast

and southwest flanks. This study only deals with the fault system along the northeast boundary in

CNM, i.e., the Redlands Fault system. The northwest striking Redlands Fault dips southwest to

south between 62° and 83° in CNM, which is parallel to the trend of the Late Paleozoic

Ancestral Rockies fault systems (e.g., Jamison, 1979; Scott, et al., 2001). The Redlands reverse

fault extends across the whole length of the CNM, but only gets exposed in a few locations

(Figure 4.1). Part of this basement fault cuts though the Chinle Formation and dies out into lower

part of the Wingate Sandstone (East Kode Canyon), whereas part of the fault only cuts lower part

of the Chinle Formation (East Canyon). The dips of Mesozoic strata increased from horizontal to

almost 60-70° in the fault zone (Figure 4.1). The Wingate Sandstone is significantly attenuated

around the fault tip zones (Jamison, 1979; Jamison and Stearns, 1982; Heyman, et al., 1986;

Davis, 1999). The offsets along the Redlands Fault vary between 400-500 m (Jamison, 1979 and

this study). In the northwest portion of the CNM (northwest from East Canyon), there is another

67

fault system, the Fruita Canyon Fault, mapped by Jamison (1979), with tens of meters offsets.

Several other sealed basement faults are inferred in this area indicated by several changes of dip

domains of Mesozoic strata towards northeast, which suggests the existence of underlying faults

(Figure 4.1).

4.3 Method and Data

Three balanced cross sections were made and reconstructed along East Canyon, North

Canyon and Kodels Canyon using trishear model of fault-propagation folding in Move software

(the Midland Valley software). The best-fit parameters that constrain the kinematic evolution of

the Redlands Faults are determined from the reconstruction. Those parameters are used for

trishear forward modeling of strain in the Redlands Fault tip zone in SVS software (in-house

software developed by Shell International Exploration & Production Company). The Geological

map and structural data, topographic data are derived from public resource of U.S. Geological

Survey (Geologic Investigations Series I-2740): Geologic Map of Colorado National Monument

and Adjacent Areas, Mesa County, Colorado. Field data of deformation bands are all from

published data by Jamison (1979) and are summarized below.

4.3.1 Method: Kinematic Trishear Model of Fault-propagation Folding

The traditional kink-band based fault-propagation folding features angular fold hinges,

uniform dips and constant thickness of fold limbs due to homogeneous strain as a result of layer-

parallel shear, and fixed fault propagation/slip ratio (P/S = 2) (e.g., Suppe, 1983; Suppe and

Medwedeff, 1990). Those characteristics of kink-band based fault-propagation folding failed to

explain the following geological features of Uncompahgre Uplift. First, monoclines in

Uncompahgre Uplift are basement involved, thick-skin structure. Second, Precambrian

basement-Mesozoic rock contact dips steeply to the northeast. Previous workers in this area

propose the model that multiple faults spread from the main thrust can create a triangular shape

68

of basement rocks that allow the rotation of the contact (e.g., Scott et al., 2001). However, there

is no geophysical data support the existence of this kind of main thrust. Third, the monoclines in

Uncompahgre Uplift show curved fold hinges and thickening and thinning of fold limbs, for

example, the Wingate Sandstone changes thickness around the fault tips.

Trishear provides an alternative model of fault-propagation folding. Trishear models

were initially developed due to the inapplicability of kink-band models for basement-involved,

thick-skin structures in some geological settings (Erslev, 1991; Allmendinger, 1998). Trishear

defined the distributed, heterogeneous strain generated by inclined shear in a triangular zone

above the fault tip, which commonly exhibits curved hinges, broad crested anticlines, non-

uniform dips, and changing thickness of fold limbs (e.g., Erslev, 1991; Allmendinger, 1998;

Hardy and Allmendinger, 2011; Dian, 2013). There are six controlling parameters determining

the shape of a fault-propagation fold in trishear model: the fault slip, P/S (ratio between fault

propagation rate and slip rate), trishear angle (the angle between the two boundaries of the

trishear zone), fault dip angle, and x and y positions of the fault tip (e.g., Hardy and Fort, 1997;

Allmendinger, 1998; Zehnder and Allmendinger, 2000; Brandenburg et al., 2012; Dian, 2013).

Trishear models have been applied to other monoclines in the Colorado Plateau to successfully

explain the geological features there (e.g., Erslev and Selvig, 1997; Cristallini and Allmendinger,

2001; Bump, 2003; Cristallini et al., 2004; Brandenburg et al., 2012).

4.3.2 Data: Characteristics of Deformation Bands in CNM

Characteristics of deformation bands are all from published field data by Jamison (1979)

and are summarized below. Deformation bands localized near the Redlands Fault zone and the

Fruita Canyon Fault zone in Wingate Sandstone, rather than pervasively distributed. They

occurred as single deformation bands, anastomosing bands (zones of deformation bands), and

69

Riedel Shear zones. The single deformation band usually forms 0.3 mm wide gouge zone, and

show minimum measurable offset of ~2 mm. When the offset increases into ~5 mm, numerous

deformation bands will develop in a narrow zone to form anastomosing bands. The anastomosing

band shows numerous wavy and intersecting gouge zones (usually no more than 5 mm,

occasionally extend to at most several centimeter wide). The Riedel Shear zone is composed of

two groups of deformation bands arranged in a specific geometry, i.e., "Riedel (R) shears" and

"conjugate Riedel (R’) shears" with opposing senses of offset. The R and R’ shears (several

centimeters in width) are conjugated Coulomb shears developed in response to a maximum

compressive principal stress (e.g., Mandl et al., 1977; Harris and Cobbold, 1985). Both porosity

and gain size are reduced in the gouge zone.

Orientation and intensity of deformation bands have been determined by Jamison (1979)

in the East Kodels Canyon and North Canyon in the Redlands Fault zone. The Riedel Shear

zones in outcrops are used to calculate shortening strain. This purpose of this study is to compare

strain distribution modeled by trishear fault-propagation folding with field data (strain,

orientation and intensity of deformation bands) along the Redlands Fault.

4.4 Results

4.4.1 Balance Reconstruction

Each of the three cross sections is perpendicular to the local strike of Redlands Fault. The

East Kodels Canyon cross section A-A’ and the North Canyon cross section B-B’ are along the

exact lines where Jamison (1979) quantitatively measured deformation bands. Horizontal layers

are used for pre-deformed strata, which is most likely true because outcrops of non-deformed

strata in the Uncompahgre Uplift are almost horizontal. Thickness and depth of each unit is

calculated from surface structural data and map pattern. Restored steps were constructed by

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progressively “undeforming” the deformed section in 2D Move software. Trishear was applied to

unfold fold limbs. Planar fault and dip slip are assumed (Davis, 1999; Bump and Davis, 2003;

Timmons et al., 2007). Whenever there is sharp change of dip domains of Mesozoic strata, an

underlying basement fault was put and named North Redlands Fault-I, North Redlands Fault-II

towards northeast. Structural data of Mesozoic sedimentary rocks are used for reconstruction.

Table 4.1 Trishear Solution Parameters for the Redlands Fault

Trishear angle

Fault

displacement (m) Propagation/Slip

Fault plane

angle

East Kodels Canyon

A-A’ 45° 200 3.5 82°

North Canyon B-B’ 45° 230 3.5 79°

East Canyon C-C’ 60° 400 3.5 75°

4.4.1.1 Cross Section Reconstruction along the East Kodels Canyon

Step A represents pre-deformed stage with horizontal layers (Figure 4.2-A). Only the top

of basement is shown in the cross section, and the bottom of basement is not indicated. The

Redlands Fault was the first fault initiated from the basement, penetrated the Chinle Formation,

extended into top part of the Wingate Sandstone, and deformed the overlying Mesozoic strata

into an “S” shape (Figure 4.2-B). The high angle Redlands Fault dipping 82° to southwest has

400 m displacement, P/S value of 3.5, and trishear angle of 45° (Table 4.1). The basement was

elevated by ~200m due to the movement of Redlands Fault. In order to accommodate the

inclined basement-Mesozoic rocks contact, another more shallowly dipping blind fault is

indicated at ~400m northeast from the Redlands Fault, named North Redlands Fault-I (Figure

4.2-C). This fault initiated from the basement and only cut part of the Chinle Formation, with the

displacement of 130 m. At about 1300 m northeast from the Redlands Fault, another fault (North

71

Redlands Fault-II) is inferred by the change of dip domains in the surface (Figure 4.2-D). The

North Redlands Fault-II dipping 72° to southwest has 260 m displacement, P/S value of 3.5, and

trishear value of 60°. This fault originated from the basement and did not cut through the

overlying sedimentary rocks. In the southwest of the Redlands Fault, the Fruita Canyon Fault

system acts as minor out-of-sequence faulting (Figure 4.2-D). Strata above all these faults

display attenuation and thickening.

4.4.1.2 Cross Section Reconstruction along the North Canyon

The Redlands Fault along the North Canyon is dipping 79° to southwest. The displacement is of

230m, which is larger than that in the East Kodels Canyon (Table 4.1). The Fault only cut the

very bottom of the Wingate Sandstone (Figure 4.3-B). The North RedLands Fault-I lies about

350 m northeast from the Red lands Fault with 140 m displacement, which initiated and died

within the basement rocks without cutting through the overlying sedimentary rocks (Figure 4.3-

C). The North Redlands Fault-II is dipping 68° to southwest, with all other parameters as same

as those along the East Kodels Canyon (Figure 4.3-D). The North Redlands Fault-II also only

cut through the basement rocks. In the southwest of the Redlands Fault, the Fruita Canyon Fault

system acts as minor out-of-sequence faulting in basement rocks with only 60 m displacement

(Figure 4.3 -D).

4.4.1.3 Cross Section Reconstruction along the East Canyon

The Redlands Fault along the East Canyon is dipping 75° to southwest. The displacement

is of 400 m, which is the largest among the three cross sections (Table 4.1). The Fault only cut

the basement, and did not penetrate into the overlying sedimentary rocks (Figure 4.4-B). The

North RedLands Fault-I is close to the Redlands Fault, which has only 80 m displacement. This

fault also initiated and died within the basement rocks (Figure 4.4-C). The North Redlands

Fault-II in this cross section shows the largest displacement (400 m) compared to the other two

72

Figure 4.2 Cross section reconstruction along the EastKodels Canyon. Abbreviations: RF –

Redlands Fault, NRF-I – North Redlands Fault-I, NRF-II – North Redlands Fault-II, FF – Fruita

Canyon Fault System.

73

Figure 4.3 Cross section reconstruction along the North Canyon. See abbreviations as in Figure

4.2.

74

Figure 4.4 Cross section reconstruction along the East Canyon. See abbreviations as in Figure

4.2.

75

(Figure 4.4-D). The Fruita Canyon Fault system is not reflected along this cross section; instead,

another tiny reverse fault is indicated by the surface data to the northeast of the North Redlands

Fault-II (Figure 4.4-D).

4.4.2 Strain Calculation

The initial stage of strata in Step A, geometry of the Redlands Fault in step B, and the

trishear parameters that defined the Redlands Fault are input into the SVS software to make a

forward modelling of the Redlands Fault development in the East Kodels Canyon and North

Canyon. The purpose of forward model is to calculate the corresponding strain of the Redlands

Fault. The forward trishear model was run with initially circular strain maker (diameter of L0),

which were deformed into ellipses. Principal shortening directions (L3, short axes of ellipse) and

extension directions (long axis of ellipse) were computed. L3 corresponds to the maximum

compressive stress (σ1), which is coincide with acute bisector of conjugate set of deformation

bands with opposing offsets according to Mohr-Coulomb criterion. The magnitude (as a

percentage) of shortening strain can then be estimated from the equation 100(1-(L3/L0)).

The modeling results for the Redlands Fault in East Kodels Canyon show the maximum

shortening strain in Wingate Sandstone occurs near the fault with magnitude of ~40%, and this

value decreases to ~5% at about 200 m away from the fault both in the upthrown block and

downthrown block (Figure 4.5). Orientation of L3 is northeast-southwest. Plunges of L3 increase

away from the fault in the upthown block (trend to be vertical), and decrease away from the fault

in the downthrown block (trend to be horizontal) (Figure 4.5). According to the orientations of

L3, dip angles of deformation bands should increase away from the fault in the upthrown block

and dip angles of deformation bands should decrease away from the fault in the downthrown

block.

76

a b

1000

1200

1400

4750 4500 m

42%

20% 15% 5%

% Strain (1-(L3/L

o)) 3

NE

Redlands fault

Wingate

SW

39%

16% 13% 5%

c d

e f

g

a b c d

e f

g

Figure 4.5 Results from forward trishear model for the kinematic evolution of Redlands Fault

along section AA’. (A) Magnitude of shortening strain with finite strain ellipses: L3 =

calculated principal shortening axis; (B) Densities of deformation bands localized around the

Redlands Faults measured in the field by Jamison and Sterns (1982). Red colored

number=permeability. Arrows point to the position where maximum shortening strain was

measured from deformation bands in the field. (C) Poles of deformation bands plotted in stereo

nets: red color dot represents sinstral offset; blue color dot represents dextral. Data of Both (B)

and (C) is from Jamison and Sterns (1982).

A

B C

77

The Redlands Fault in North Canyon did not cut the Wingate Sandstone. The modelling

results show the maximum shortening strain (~40%) in Wingate Sandstone occurred in the

triangular zone above the fault tip and decrease to ~5% at ~200 m away from the fault tip both in

the forelimb and backlimb portion (Figure 4.6). Orientation of L3 exhibits the similar trend as

that in East Kodels Canyon.

4.5 Discussion

Strain measured from deformation bands in outcrops are in good agreement with

predictions of trishear modelling. Shortening strain are calculated using field data of deformation

bands at four stations in the upthrown portion by Jamison (1979) along the East Kodels Canyon

(Figure 4.5): 39%, 16%, 13% and 5%. In the same locations, the magnitude of shortening strains

predicted by modelling are about 40%, 20%, 15% and 5%, respectively. Field data show high

density of deformation bands developed in the lower portion of Wingate Sandstone. Density of

deformation bands increase as the magnitude of strain increases toward the fault in general.

Permeability is significantly reduced near the fault when the magnitude of shortening strain

exceeds 15%. It is very hard to correlate strain with density of deformation bands in the

downthrown block because the lower portion of Windgate Sandstone is not exposed (Jamison

and Sterns, 1982).

Orientations of deformation bands in outcrops along the East Kodels Canyon are also

consistent with predictions by trishear modelling (Figure 4.5). Field data display that

deformation bands are dipping more shallowly towards the fault in upthrown block, whereas

deformation bands are dipping more steeply in downthrown block towards the fault. For example,

deformation bands in stations A, B, D are steeper (nearly vertical) than those in stations C and E

78

Figure 4.6 Results from forward trishear model for the kinematic evolution of Redlands Fault

along setion BB’. (A) Magnitude of shortening strain with finite strain ellipses: L3 – calculated

principal shortening axis; (B) Densities of deformation bands localized around the Redlands

Faults measured in the field by Jamison and Sterns (1982). Red colored number – permeability.

Arrows points to the position where maximum shortening strain was measured from deformation

bands in the field. (C) Poles of deformation bands plotted in stereonets: red dots represent

sinstral offset; blue dots represent dextral. Data of both (B) and (C) are from Jamison and Sterns

(1982).

79

in upthrown block. Deformation bands in station F are steeper than those in station G in general

in downthrown block (Figure 4.5).

Surprisingly moderate density of deformation bands occurred in cross section along

North Canyon although the Wingate Sandstone here show ~40% attenuation (Jamison, 1979;

Jamison and Stern, 1982) (Figure 4.6). The density measurement is suspected because there are

several high density intervals are covered and cannot get access to (Jamison, 1979; Jamison and

Sterns, 1982). The orientations of deformation bands in this transect are in good agreement with

predictions by modelling (Figure 4.6): at station J', the deformation band surfaces are nearly

vertical and become nearly horizontal in the lower forelimb (station C’ and station I’).

The good agreement between modelling results and field data indicates that trishear

model of fault-propagation folding can account for distribution and orientation of deformation

bands in East Kodels Canyon and North Canyon. The combination of modelling results and field

data suggest that density of deformation bands increases as strain increases in homogeneous

lithology. Permeability will decrease significantly when shortening strain is over ~15% (this

number should change in differently lithology). However strain-density relationship should be

used by caution in view of the fact that under the same strain, the less porous, calcite-cemented

layers in Wingate Sandstone contain less deformation bands than the porous layers nearby

(Jamison, 1979; Jamison and Stern, 1982).

4.6 Conclusions

We conducted balance cross section reconstruction along three traverses in northwest

portion of CNM in Uncompahgre Uplift. Trishear modeling with planar, dip-slip fault is

successfully used to reproduce geometry of the monocline. The reconstruction results indicate

80

that trishear model of fault-propagation folding is viable kinematics for Laramide monocline

development than traditional kink-band style fault-propagation folding.

The good agreement between field data and modelling strain corresponding to the

Redlands Fault movement demonstrates that trishear model of fault-propagation folding can be

used to predict distribution and orientation of deformation bands in subsurface reservoir, which

might have potential influence on fluid flow path.

81

CHAPTER 5

SUMMARY AND CONCLUSIONS

This dissertation includes two parts: kinematic evolution of the Himalayan fold-thrust

belt along the collisional orogenic belts on hundreds of kilometer scale, and trishear model of

fault-propagation folding to predict deformation bands associated with growth of the basement-

cored monoclines in Colorado Plateau on hundreds of meter to millimeter scale. The common

goal of these two parts is to better understand contractional tectonics at different scale. Research

on the Himalayan fold-thrust belt is to examine the viability of the Himalayan growth models

through three components: 1) structural and kinematic mapping combined with microstructural

investigations to address key questions about the regional structure (Chapter 2); 2) apatite and

zircon fission track thermochronology to constrain the thermal history (Chapter 3); 3)

interpretation of data from the first two research components via balanced palinspastic

reconstruction (Chapter 3). Research on the Uncompahgre Uplift is to explore trishear model of

fault-propagation folding to predict popularity of deformation bands associated with reverse

faulting. The main conclusions of each project are summarized below.

5.1 Growth of the Himalayan Fold-thrust belt Dominated Duplexing Processes

Our work in the northwestern Indian Himalaya advances knowledge about ongoing

Himalayan growth, which is generally thought to be dominated by duplexing and/or extrusion

processes. Duplexing models highlight accretion of material from the subducting plate to the

over-riding orogenic wedge that may occur through any or all of three processes: frontal

accretion involving forward propagation of the frontal thrust, expansion of the orogen via

incremental accretion along the basal shear zone, and discrete accretion of km-to-10 km-scale

thrust horses along ramps of the Himalayan sole thrust. Extrusion models generally focus on

82

southwards translation of a fault-bounded block towards the surface, with major out-of-sequence

thrust faulting below and normal faulting above.

Our field-based analytical work in the northwestern Indian Himalaya resolves the

uncertain relationship between two major regional structures: the Berinag thrust and the Tons

thrust, which share the same footwall rocks, are in fact the same structure. Our mapping

documents a new discovery: a ~ 450 m thick top-to-southwest shear zone, termed the Pabbar

thrust, in the NW Indian Himalaya. The Pabbar thrust placed the Outer Lesser Himalayan

Sequence (the Tons thrust hanging wall) directly on the Berinag Group (the Berinag thrust

hanging wall). The shear zone is characterized by sheath folds, S-C fabrics and mylonitic fabrics,

all with top-to-the-southwest shear sense. Both the field observations and quartz microstructures

indicate the Pabbar thrust developed earlier and hotter (i.e., deeper), followed by accretion of the

Berinag-Tons thrust sheet. Along-strike extension of these kinematics and corresponding

geometries is consistent with the observed orogenic framework and resolves a stratigraphic

continuity problem across the India – west Nepal border, where prior work suggests that

structures are continuous but stratigraphy does not match. The resultant structural framework is

consistent with duplexing processes and limits extrusion to a minor role in mountain-building.

Our new set of thermochronological data place robust time constraint on Himalayan

mountain building process: 12.5±0.4 to 6.5±0.5 Ma ZFT ages indicate Late Miocene activity of

the Berinag-Tons thrust; 26.8±1.8 to 28.8 ±1.8 Ma ZFT ages of the southernmost exposure of the

THS in the hanging wall of the MCT suggest initiation of the MCT in Late Oligocene. The

thermochronological data is also used to confine the pre-deformational framework

A balanced palinspastic reconstruction across the northwestern Indian Himalaya reveals

~380km (66%) shortening along the MCT, the STD and deformation of the LHS. The Mountain

83

building process includes 1) Late Oligocene–Middle Miocene emplacement of the GHC, and

juxtaposing of the THS atop LHS. 2) Middle–Late Miocene accretion of the Pabbar thrust and

the Berinag-Tons thrust sheet and 3) subsequent growth via a hinterland-dipping upper crustal

duplexing and an antiformal stack of mid-crustal horses developed simultaneously, and frontal

accretion of sub-Himalayan rocks. The kinematic relationship of the Pabbar thrust and the

Berinag-Tons thrust, and our palinspastic reconstruction demonstrate that discrete duplexing

processes dominated ongoing growth of the northwest Indian Himalaya and limited extent of

out-of-sequence faulting (<3% of shortening).

5.2 Kinematic Trishear Fault-propagation Folding Model to Predict Deformation Bands

The Uncompahgre uplift was formed due to the Late Cretaceous to middle Eocene (~70-

50 Ma) Laramide Orogeny by reactivation of inherited high-angle Precambrian basement faults

at depth. The traditional kink-band based fault-propagation folding featured by angular fold

hinges, uniform dips and constant thickness of fold limbs failed to explain inclined Precambrian

basement-Mesozoic rock contact, curved fold hinges and thickening and thinning of fold limbs.

Trishear provides an alternative model of fault-propagation folding characterized by

heterogeneous strain generated by inclined shear in a triangular zone above the fault tip, which

commonly exhibits curved hinges, broad crested anticlines, non-uniform dips, and changing

thickness of fold limbs.

We conducted balance cross section reconstruction along three traverses in northwest

portion of CNM in Uncompahgre Uplift. Trishear modeling with planar, dip-slip fault is

successfully used to reproduce geometry of the monocline. The good agreement between

deformation bands data in field and modelling strain demonstrates that trishear model of fault-

propagation folding is viable kinematics to predict distribution and orientation of deformation

84

bands. The correlation may have significant implications with regard to better constrain the fluid

pathways around faults because of low permeability of deformation bands.

85

REFERENCES

Acton, C.E., K. Priestley, S. Mitra, and V.K. Gaur (2010), Crustal structure of the Darjeeling–

Sikkim Himalaya and southern Tibet, Geophys. J. Int., 184, 829-852.

Adlakha, V., R.C. Patel, and L. Nand (2013), Exhumation and its mechanisms: A review of

exhumation studies in the Himalaya, J. Geol. Soc India, 81, 481-502.

Ahmad, T., N. Harris, M. Bickle, H. Chapman, J. Bunbury, and C. Prince (2000), Isotopic

constraints on the structural relationships between the Lesser Himalayan Series and the

High Himalayan Crystalline Series, Garhwal Himalaya, Geol. Soc. Am. Bull., 112, 467-

477.

Allmendinger, R.W. (1998), Inverse and forward numerical modeling of trishear fault-

propagation folds, Tectonics, 17, 640-656.

Allmendinger, R.W., J.A. Brewer, L.D. Brown, S. Kaufman, J.E., Oliver, and R.S. Houston

(1982), COCORP profiling across the Rocky Mountain Front in southern Wyoming, Part

2: Precambrian basement structure and its influence on Laramide deformation,

Geological Society of American Bulletin, 93, 1253-1263.

Antonellini, M., and A. Aydin (1994), Effect of faulting on fluid flow in porous sandstones:

petrophysical properties, AAPG Bulletin, 78, 355-377.

Antonellini, M., and A. Aydin (1995), Effect of faulting on fluid flow in porous sandstones:

geometry and spatial distribution, AAPG Bulletin, 79, 642-671.

Antonellini, M.A., A. Aydin, and D.D. Pollard (1994), Microstructure of deformation bands in

porous sandstones at Arches National Park, Journal of Structural Geology, 16, 941-959.

Antonellini, M.A., A. Aydin, and L. Orr (1999), Outcrop aided characterization of a faulted

hydrocarbon reservoir: Arroyo Grande oil field, California, USA, in: Haneberg, W.C.,

P.S. Mozley, C.J. Moore, & L.B. Goodwin, eds., Faults and Subsurface Fluid Flow,

Geophysical Monograph, 113, 7-26.

Arita, K. (1983), Origin of the inverted metamorphism of the Lower Himalayas Central Nepal.

Tectonophysics, 95, 43-60.

Armstrong, H.A., and M.B. Allen (2011), Shifts in the Intertropical Convergence Zone,

Himalayan exhumation, and late Cenozoic climate, Geology, 39, 11-14.

Aubrey, W.M. (1998), A newly discovered, widespread fluvial facies and unconformity marking

the upper Jurassic/Lower Cretaceous boundary, Colorado Plateau, Modern Geology, 22,

209–233.

Auden, J.B. (1934), The geology of the Krol Belt, Geol. Survey of India Records, 67, 357–454.

86

Avouac, J.P. (2003), Mountain building, erosion, and the seismic cycle in the Nepal, Advances in

Geophysics, 46, 1-80.

Avouac, J.P. (2007), Dynamic processes in extensional and compressional settings—Mountain

building: From earthquakes to geological deformation, Treatise of Geophysics, 6, 377-

439.

Aydin, A. (1978), Small faults formed as deformation bands in sandstone, Pageoph, 116, 913-

930.

Aydin, A., and A.M. Johnson (1978), Development of faults as zones of deformation bands and

as slip surfaces in sandstone, Pure and Applied Geophysics, 116, 931-942.

Aydin, A., and A.M. Johnson (1983), Analysis of faulting of porous sandstone, Journal of

Structural Geology, 5, 19-31.

Aydin, A., Borja, R.I., and P. Eichhubl (2006), Geological and mathematical framework for

failure modes in granular rock, Journal of Structural Geology, 28, 83-98.

Ballas, G., R. Soliva, J.-P. Sizun, A. Benedicto, T. Cavailhes, and S. Raynaud (2012), The

importance of the degree of cataclasis in shear bands for fluid flow in porous sandstone

(Provence, France), AAPG Bulletin, 96, 2167-2186.

Ballas, G., R. Soliva, J.-P. Sizun, H. Fossen, A. Benedicto, and E. Skurtveit (2013), Shear-

enchanced compaction bands formed at shallow burial conditions; implications for fluid

flow (Provence, France), Journal of Structural Geology, 47, 3-15.

Ballas, G., R. Soliva, A. Benedicto, and J.P. Sizun (2014), Control of tectonic setting and large-

scale faults on the basin-scale distribution of deformation bands in porous sandstone

(Provence, France), Marine and Petroleum Geology, 1-18.

Bally, A.W., and A.R. Palmer (1989), The geology of North America—an overview, Boulder,

Colorado, Geological Society of America, 619 p.

Beach, A., A.I. Welbon, P.J. Brockbank, and J.E. McCallum (1999), Reservoir damage around

faults: Outcrop examples from Suez rift, Pet. Geosci., 5, 109-116.

Beach, A., J.L. Brown, A.I. Welbon, J.E. McCallum, P. Brockbank, and S. Knott (1997),

Characteristics of fault zones in sandstones from NW England: application to fault

transmissibility, in: Meadows, N.S., S.P. Trueblood, M. Hardman, and G. Cowan, eds.,

Petroleum Geology of the Irish Sea and Adjacent Areas. Geological Society, London,

Special Publications, 124, 315-324.

Beaumont, C., R.A. Jamieson, M.H. Nguyen, and B. Lee (2001), Himalayan tectonics explained

by extrusion of a low-viscosity crustal channel coupled to focused surface denudation,

Nature, 414, 738-742.

87

Beaumont, C., R.A. Jamieson, M.H. Nguyen, and S. Medvedev (2004), Crustal channel flows: 1.

Numerical models with applications to the tectonics of the Himalayan‐Tibetan Orogen,

J. Geophys. Res., 109, B06406, doi:10.1029/2003JB002809.

Berger, A., F. Jouanne, R. Hassani, and J.L. Mugnier (2004), Modelling the spatial distribution

of present-day deformation in Nepal: how cylindrical is the Main Himalayan Thrust in

Nepal? Geophys. J. Int., 156, 94-114.

Bernard, X.D., P. Labaume, C. Darcel, P. Davy, and O. Bour (2002), Cataclastic slip band

distribution in normal fault damage zones, Nubian sandstones, Suez rift, Journal of

Geophysical Research, 107, doi: 10.1029/2001JB000493.

Bernet, M., P. van der Beek, R. Pik, P. Huyghe, J. L. Mugnier, E. Labrin, and A. Szulc (2006),

Miocene to recent exhumation of the central Himalaya determined from combined

detrital zircon fission-track and U/Pb analysis of Siwalik sediments, western Nepal, Basin

Res., 18(4), 393–412, doi:10.1111/j.1365-2117.2006.00303.x.

Bernet, M., 2009, A field-based estimate of the zircon fission track closure temperature,

Chemical Geology, 259, 181–189, doi:10.1016/j.chemgeo.2008.10.043.

Besuelle, P. (2001), Evolution of strain localisation with stress in a sandstone: brittle and semi-

brittle regimes, Physical Chemistry of the Earth, A26, 101-106.

Bhargava, O.N. (1976), Geology of the Krol belt and associated formations: A reappraisal, Geol

Survey of India Memoirs, 106, 167-234.

Bird, P. (1998), Kinematic history of the Laramide orogeny in latitudes 35-49N, western United

States, Tectonics, 17, 780-801.

Blackstone, D.L. (1993), Precambrian basement map of Wyoming: Outcrop and structural

configuration, in Mayer, L., ed., Extensional Tectonics of the Southwestern United States:

A Perspective on Processes and Kinematics, Geological Society of America Special

Paper, 208, 335-337.

Blythe, A.E., D.W. Burbank, A. Carter, K. Schmidt, and J. Putkonen (2007), Plio-Quaternary

exhumation history of the central Nepalese Himalaya: 1. Apatite and zircon fission-track

and apatite [U-Th]/He analyses, Tectonics, 26, doi:10.1029/2006TC001990.

Bojar, A.-V., H. Fritz, S. Nicolescu, M. Bregar, and R.P. Gupta (2005), Timing and mechanisms

of Central Himalayan exhumation: discriminating between tectonic and erosion processes,

Terra Nova, 17, 427-433.

Bollinger, L., J.P. Avouac, O. Beyssac, E.J. Catlos, T.M. Harrison, M. Grove, B. Goffé, and S.

Sapkota (2004), Thermal structure and exhumation history of the Lesser Himalaya in

central Nepal, Tectonics, 23, TC5015, doi:10.1029/2003TC001564.

Bollinger, L., P. Henry, and J. P. Avouac (2006), Mountain building in the Nepal Himalaya:

thermal and kinematic model, Earth Planet. Sci. Lett., 244, 58-71.

88

Bonnet, C., J. Malavieille, and J. Mosar (2007), Interactions between tectonics, erosion, and

sedimentation during the recent evolution of the Alpine orogen: Analogue modeling

insights, Tectonics, 26, doi: 10.1029/2006TC002048.

Bookhagen, B., R.C. Thiede, and M.R. Strecker (2005a), Abnormal monsoon years and their

control on erosion and sediment flux in the high, arid northwest Himalaya, Earth Planet.

Sci. Lett., 231, 131-146.

Bookhagen, B., R.C. Thiede, and M.R. Strecker (2005b), Late Quaternary intensified monsoon

phases control landscape evolution in the northwest Himalaya, Geology, 33, 149-152.

Boos, W.R., and Z. Kuang (2010), Dominant control of the South Asian monsoon by orographic

insulation versus plateau heating, Nature, 463, 218-222.

Bordet, P., M. Colchen, and P. Le Fort (1972), Some features of the geology of the Annapurna

range Nepal Himalaya, Himalayan Geology, 2, 537–563.

Borja, R.I. and A. Aydin (2004), Computational modeling of deformation bands in granular

media. I. Geological and mathematical framework, Computer Methods in Applied

Mechanical Engineering, 193, 2667-2698.

Brandenburg, J.P., F.O. Alpak, J.G. Solum, and S.J. Naruk (2012), A kinematic trishear model to

predict deformation bands in a fault-propagation fold, East Kaibab monocline, Utah,

AAPG Bulletin, 96, 109-132.

Brandes, C., and D.C., Tanner (2012), Three-dimensional geometry and fabric of shear

deformation-bands in unconsolidated Pleistocene sediments, Tectonophysics, 518-521,

84-92.

Brewer, J.A., R.W. Allmendinger, L.D. Brown, J.E. Oliver, and S. Kaufman (1982), COCORP

profiling across the Rocky Mountain Front in southern Wyoming, Part 1: Laramide

structure, Geological Society of American Bulletin, 93, 1242-1252.

Brown, W.G. (1988), Deformation style of Laramide uplifts in the Wyoming foreland, in

Interaction of the Rocky Mountain foreland and the Cordilleran Thrust Belt, edited by C.J.

Schmidt and W.L.J. Perry, Mem. Geol. Soc. Am., 171, 1-25.

Brown, W.G. (1993), Structural style of Laramide basement-cored uplifts and associated folds,

in Geology of Wyoming, edited by A.W. Snoke, J.R. Steidtmann, and S.M. Roberts,

Mem. Geol. Surv. Wyo., 5, 312-371.

Bump, A.P. (2003), Reactivation, trishear modeling, and folded basement in Laramide uplifts:

Implications for the origins of intra-continental faults, GSA Today, 13, 4-10.

Bump, A.P. (2004), Three-dimensional Laramide deformation of the Colorado Plateau;

competing stresses from the Sevier thrust belt and the fl at Farallon slab, Tectonics, 23,

doi: 10.1029/2001TC001329.

89

Bump, A.P., and G.H. Davis (2003), Late Cretaceous-early Tertiary Laramide deformation of the

northern Colorado Plateau, Utah and Colorado, Journal of Structural Geology, 25, 421-

440.

Burbank, D. W., A.E. Blythe, J. Putkonen, B. Pratt-Sitaula, E. Gabet, M. Oskin, A. Barros, and T.

Ojha (2003), Decoupling of erosion and precipitation in the Himalayas, Nature, 426, 652-

655.

Burchfiel, B.C., and L.H. Royden (1985), North-south extension within the convergent

Himalayan region, Geology, 13, 679-682.

Burchfiel, B. C., C. Zhileng, K. V. Hodges, L. Yuping, L. H. Royden, D. Changrong, and X.

Jiene (1992), The South Tibetan detachment system, Himalayan orogen: Extension

contemporaneous with and parallel to shortening in a collisional mountain belt, Geol. Soc.

Am. Spec. Pap., 269, 1–41.

Burg, J. P., M. Brunel, D. Gapais, G. M. Chen, and G. H. Liu (1984), Deformation of

leucogranites of the crystalline Main Central Sheet in southern Tibet (China), J. Struct.

Geol., 6, 535-542.

Caddick, M.J., M.J. Bickle, N.B.W. Harris, T.J.B. Holland, M.S.A. Horstwood, R.R. Parrish, and

T. Ahmad (2007), Burial and exhumation history of a Lesser Himalayan schist:

Recording the formation of an inverted metamorphic sequence in NW India, Earth Planet.

Sci. Lett., 264, 375-390.

Caldwell, W.B., S.L. Klemperer, J.F. Lawrence, S.S. Rai, Ashish (2013), Characterizing the

Main Himalayan Thrust in the Garhwal Himalaya, India with receiver function CCP

stacking, Earth Planet. Sci. Lett., 367, 15-27.

Cashion, W.B. (1973), Geologic and structure map of the Grand Junction quadrangle, Colorado

and Utah, U.S. Geol. Surv., Reston, Va.

Cashman, S., and K. Cashman (2000), Cataclasis and deformation-band formation in

unconsolidated marine terrace sand, Humboldt County, California, Geology, 28, 111-114.

Catlos, E.J., T.M. Harrison, M.J. Kohn, M. Grove, F.J. Ryerson, C.E. Manning, and B.N. Upreti

(2001), Geochronologic and thermobarometric constraints on the evolution of the Main

Central Thrust, central Nepal Himalaya, J. Geophys. Res., 106, 16177-16204.

Catlos, E.J., C.S. Dubey, T.M. Harrison, and M.A. Edwards (2004), Late Miocene movement

within the Himalayan Main Central Thrust shear zone, Sikkim, north-east India, J.

Metamorph.Geol., 22, 207–226.

Célérier, J., T.M. Harrison, A.A.G. Webb, and A. Yin, (2009a), The Kumaun and Garwhal

Lesser Himalaya, India; Part 1, Structure and stratigraphy, Geol. Soc. Am. Bull., 121,

1262-1280.

90

Célérier, J., T.M. Harrison, O. Beyssac, F. Herman, W.J. Dunlap, and A.A.G. Webb (2009b),

The Kumaun and Garwhal Lesser Himalaya, India; Part 2, Thermal and deformation

histories, Geol. Soc. Am. Bull.,121, 1281-1297.

Chambers, J.A., T.W. Argles, M.S.A. Horstwood, N.B.W. Harris, R.R. Parrish, and T. Ahmad

(2008), Tectonic implications of Palaeoproterozoic anatexis and Late Miocene

metamorphism in the Lesser Himalayan Sequence, Sutlej Valley, NW India, Journal of

the Geological Society, 165, 725-737.

Chamoli, A., A. Pandey, V. Dimri, P. Banerjee (2011), Crustal configuration of the northwest

Himalaya based on modeling of gravity data, Pure Appl. Geophys., 168, 827-844.

Chapin, C.E., and S.M. Cather (1981), Eocene tectonics and sedimentation in the Colorado

Plateau-Rocky Mountain area, Arizona Geological Society Digest, 14, 173-198.

Charalampidou, E.M., S.A. Hall, S. Stanchits, H. Lewis, and G. Viggiani (2011),

Characterization of shear and compaction bands in a porous sandstone deformed under

triaxial compression, Tectonophysics, 503, 8-17.

Charalampidou, E.M., S.A. Hall, S. Stanchits, G. Viggiani, and H. Lewis (2012), Shear-

enhanced compaction band identification at the laboratory scale using acoustic and full-

field methods, Int. J. Rock Mechanics Mining Sci., in press.

Chemenda, A.I. (2007), The formation of shear-band/fracture networks from a constitutive

instability: theory and numerical experiment, J. Geophys. Res., 112, B11404 doi:

10.1029/2007JB005026.

Chemenda, A.I. (2009), The formation of tabular compaction-band arrays: theoretical and

numerical analysis, J. Mech. Phys. Solids, 57, 851–868.

Chemenda, A.I., Si-H., Nguyen, J.-P., Petit, and J., Ambre (2011), Mode I cracking versus

dilatancy banding: experimental constraints on the mechanisms of extension fracturing,

Journal of Geophysical Research, 116, B04401. doi: 10.1029/2010JB008104.

Chemenda, A.I., C. Wibberley, and E. Saillet (2012), Evolution of compactive shear deformation

bands: Numerical models and geological data, Tectonophysics, 526-529, 56-66.

Cilona, A., P. Baud, E. Tondi, F. Agosta, S. Vinciguerra, A. Rustichelli, and C.J. Spiers (2012),

Deformation bands in porous carbonate grainstones: Field and laboratory observations,

Journal of Structural Geology, 45, 137-157.

Clift, P. D., L. Giosan, J. Blusztajn, I.H. Campbell, C. Allen, M. Pringle, A.R. Tabrez, M. Danish,

M.M. Rabbani, A. Alizai, A. Carter, and A. Luckge (2008), Holocene erosion of the

Lesser Himalaya triggered by intensified summer monsoon, Geology, 36, 79-82.

Cole, R.D., and G.E. Moore (1994), Sequence stratigraphy of Cedar Mountain-Dakota interval,

western and southern Piceance Creek basin, Colorado: American Association of

Petroleum Geologists Annual Convention Program, 3, 124.

91

Corrigan, J.D. (1991), Inversion of apatite fission track data for thermal history information, J.

Geophys. Res. 96, 10347-10360.

Crawford, B.R. (1998), Experimental fault sealing: shear band permeability dependency on

cataclastic fault gouge characteristics, in: Coward, M.P., H. Johnson, and T.S. Daltaban,

eds., Structural Geology in Reservoir Characterization, Geological Society, London,

Special Publications, 127, 83-97.

Cristallini, E.O., and R.W. Allmendinger (2001), Pseudo 3-D modeling of trishear fault-

propagation folding, Journal of Structural Geology, 23, 1883-1899.

Cristallini, E.O., L. Giambiagi, and R.W. Allmendinger (2004), True three-dimensional trishear:

A kinematic model for strike-slip and oblique-slip deformation, GSA Bulletin, 116, 938-

952.

Davis, G.H. (1978), Monocline fold pattern of the Colorado Plateau, in: Laramide Folding

Associated with Basement Block Faulting in the Western United States, edited by V.I.

Matthews, Mem. Geol. Soc. Am., 151, 215-233.

Davis, G.H. (1999), Structural geology of the Colorado Plateau region of southern Utah with

special emphasis on deformation bands, Geological Society of America Special Paper,

342.

DeCelles, P. G., D. M. Robinson, J. Quade, T. P. Ojha, C. N. Garzione, P. Copeland, and B. N.

Upreti (2001), Stratigraphy, structure and tectonic evolution of the Himalayan fold-thrust

best in western Nepal, Tectonics, 20, 487-509.

Deeken, A., R.C. Thiede, E.R. Sobel, J.K. Hourigan, and M.R. Strecker (2011), Exhumational

variability within the Himalaya of northwest India, Earth Planet. Sci. Lett., 305, 103-114.

Donelick, R.A., R.A. Ketcham, and W.D. Carlson (1999), Variability of apatite fission-track

annealing kinetics: II. Crystallographic orientation effects, The American Mineralogist,

84, 1224–1234.

Donelick, R.A., P. B. O’Sullivan, and R.A. Ketcham (2005), Apatite fi ssion-track analysis, Rev.

Mineral Geochem., 58, 49-94.

Dunham, R.J., 1962, Classification of carbonate rocks according to depositional textures, in Ham,

W.E., ed., Classification of Carbonate Rocks: American Association of Petroleum

Geologists Memoir 1, p.108–121.

Dupont-Nivet, G., W. Krijgsman, C.G. Langereis, H.A. Abels, S. Dai, and X.M. Fang (2007),

Tibetan plateau aridification linked to global cooling at the Eocene-Oligocene transition,

Nature, 445, 635-638.

Eichhubl, P., W.L. Taylor, D.D. Pollard, and A. Aydin (2004), Paleo-fluid flow and deformation

in the Aztec Sandstone at the Valley of Fire, Nevada—Evidence for the coupling of

hydrogeologic, diagenetic, and tectonic processes, GSA Bulletin, 116, 1120-1136.

92

Epard, J.L., A. Steck, J.C. Vannay, and J. Hunziker (1995), Tertiary Himalayan structures and

metamorphism in the Kulu Valley (Mandi-Khoksar Transect of the Western Himalaya)—

Shikar-Beh-Nappe and Crystalline Nappe, Schweizerische Mineralogische und

Petrographische Mitteilungen, 75, 59-84.

Erslev, E.A. (1991), Trishear fault-propagation folding, Geology, 24, 617-620.

Erslev, E.A. (2001), Multistage, multidirectional Tertiary shortening and compression in north-

central New Mexico, Geological Society of America Bulletin, 113, 63-74.

Erslev, E.A., and J.L. Rogers (1993), Basement-cover geometry of Laramide fault-propagation

folds, in C.J. Schmidt, R.B. Chase, and E.A. Erslev, eds., Laramide basement

deformation in the Rocky Mountain foreland of the western United States, Geological

Society of America Special Paper, 280, 125-146.

Erslev, E.A., and B. Selvig (1997), Thrusts, backthrust and triangle zones: Laramide deformation

in the northeastern margin of the Colorado Front Range, Colorado Front Range

Guidebook, 65-76.

Erslev, E.A., and N.V. Koenig (2009), Three-dimensional kinematics of Laramide, basement-

involved Rocky Mountain deformation, USA: Insights from minor faults and GIS-

enhanced structure maps, Geological Society of America Memoirs, 204, 125-150.

Fisher, Q.J., and R.J. Knipe (2001), The permeability of faults within siliciclastic petroleum

reservoirs of the North Sea and Norwegian Continental Shelf, Marine and Petroleum

Geology, 18, 1063-1081.

Fleischer, R.L, P.B. Price, and R.M. Walker (1975), Nuclear Tracks in Solids: Principles and

Applications. University of California Press, Berkeley

Flodin, E.A., M. Gerdes, A. Aydin, and W.D. Wiggins (2005), Petrophysical properties of

cataclastic fault rock in sandstone, in: Sorkhabi, R. and Y. Tsuji, eds., Faults, Fluid Flow,

and Petroleum Traps, AAPG Memoirs, 85, 197-217.

Foos, A. (1999), Geology of Colorado National Monument.

Fossen, H. and J. Hesthammer (1997), Geometric analysis and scaling relations of deformation

bands in porous sandstone, Journal of Structural Geology, 19, 1479-1493.

Fossen, H., and A. Bale (2007), Deformation bands and their influence on fluid flow, AAPG

Bulletin, 91, 1685-1700.

Fossen, H., R.A. Schultz, Z.K. Shipton, and K. Mair (2007), Deformation bands in sandstone: a

review, Journal of the Geological Society, London, 164, 1-15.

Frank, W., M. Thoni and F. Purtscheller (1977), Geology and petrography of Kullu–South Lahul

area, Colloques Internationaux du CNRS, 286, 147-172.

93

Gabrielsen, R.H., and A.G. Koestler (1987), Description and structural implications of fractures

in late Jurassic sandstones of the Troll Field, northern North Sea, Norsk Geologisk

Tidsskrift, 67, 371-381.

Gallagher, K. (1995), Evolving temperature histories from apatite fission-track data. Earth

Planet Sci. Lett., 136, 421-435.

Gansser, A. (1964), The geology of the Himalayas, New York, Wiley Interscience, 289 p.

Gibson, R.G. (1998), Physical character and fluid-flow properties of sandstone-derived fault

zones, , in: Coward, M.P., H. Johnson, and T.S. Daltaban, eds., Structural Geology in

Reservoir Characterization, Geological Society, London, Special Publications, 127, 83-97.

Godard, V., J. Lavé, and R. Cattin (2006), Numerical modelling of erosion processes in the

Himalayas of Nepal: effects of spatial variations of rock strength and precipitation,

Geological Society, London, Special Publications, 253, 341-358.

Godard, V., and D.W. Burbank (2011), Mechanical analysis of controls on strain partitioning in

the Himalayas of central Nepal, J. Geophys. Res., 116, B10402.

Grandin, R., M.P. Doin, L. Bollinger, B. Pinel-Puyssegur, G. Ducret, R. Jolivet and S.N. Sapkota

(2012), Long-term growth of the Himalaya inferred from interseismic InSAR

measurement, Geology, 40, 1059-1062.

Grujic, D., I. Coutand, B. Bookhagen, S. Bonnet, A. Blythe, and C. Duncan (2006), Climatic

forcing of erosion, landscape, and tectonics in the Bhutan Himalayas, Geology, 34, 801-

804.

Harris, L.B. and P.R. Cobbold (1984). Development of conjugate shear bands during simple

shearing, J. Struct. Geol., 7, 37–44.

Hardy, S., and M. Ford (1997), Numerical modeling of trishear fault propagation folding,

Tectonics, 16, 841-854.

Hardy, S., and R.W. Allmendinger (2011), Trishear: A review of kinematics, mechanics, and

applications, in McClay, K., J. Shaw, and J. Suppe, eds., Thrust fault-related folding,

AAPG Memoir, 94, 95-119.

Harrison T.M., F.J. Ryerson, P. Le Fort, A. Yin, O.M. Lovera and E.J. Catlos (1997), A Late

Miocene-Pliocene origin for the Central Himalayan inverted metamorphism, Earth

Planet. Sci. Lett., 146, 1-8.

Harrison, T.M., M. Grove, O.M. Lovera, and E.J. Catlos (1998), A model for the origin of

Himalayan anatexis and inverted metamorphism, J. Geophys. Res., 103, 27017-27032.

He, D., A.A.G. Webb, K.P. Larson, and A.K. Schmitt (2014), Extrusion vs. duplexing models of

Himalayan mountain building 2: The South Tibet detachment at the Dadeldhura klippe,

Tectonics, in review.

94

Heim, A., and A. Gansser (1939), Central Himalaya geological observations of the Swiss

Expedition 1936, Zurich, Gebrüder Fretz, 246 p.

Herman, F., P. Copeland, J.P. Avouac, L. Bollinger, G. Maheo, P. Le Fort, S. Rai, D. Foster, A.

Pecher, K. Stuwe, and P. Henry (2010), Exhumation, crustal deformation, and thermal

structure of the Nepal Himalaya derived from the inversion of thermochronological and

thermobarometric data and modeling of the topography, J. Geophys. Res., 115, doi:

10.1029/2008JB006126.

Hesthammer, J. and H. Fossen (1999), Evolution and geometries of gravitational collapse

structures with examples from the Statfjord Field, northern North Sea, Marine and

Petroleum Geology, 16, 259-281.

Hesthammer, J., and H. Fossen (2000), Uncertainties associated with fault sealing analysis.

Petroleum Geoscience, 6, 37-45.

Hesthammer, J., P.A. Bjørkum, and L.I. Watts (2002), The effect of temperature on sealing

capacity of faults in sandstone reservoirs: examples from the Gullfaks and Gullfaks Sør

fields, North Sea, AAPG Bulletin, 86, 1733-1751.

Hetenyi, G., R. Cattin, J. Vergne, and J.L. Nabelek (2006), The effective elastic thickness of the

India Plate from receiver function imaging, gravity anomalies and thermomechanical

modeling, Geophys. J. Int., 167, 1106-1118.

Heyman, O.G. (1983), Distribution and structural geometry of faults and folds along the

northwestern Uncompahgre Uplift, western Colorado and eastern Utah, Grand Junction

Geological Society Field Trip Guidebook, 45-57.

Heyman, O.G., P.W. Huntoon, and M.A. White-Heyman (1986), Laramide deformation of the

Uncompahgre Plateau – geometry and mechanisms, Rocky Mountain Association of

Geologists, 65-76.

Heynekamp, M.R., L.B. Goodwin, P.S. Mozley, and W.C. Haneberg (1999), Controls on fault

zone architecture in poorly lithified sediments, Rio Grande Rift, New Mexico:

implications for fault zone permeability and fluid flow, in: Haneberg, W.C., P.S. Mozley,

C.J. Moore, & L.B. Goodwin, eds., Faults and Subsurface Fluid Flow, Geophysical

Monograph, 113, 27-49.

Hirth, G., and J. Tullis, (1992), Dislocation creep regimes in quartz aggregates, J. Struct. Geol.,

14, 145-159.

Hodges, K.V. (2000), Tectonics of the Himalaya and southern Tibet from two perspectives, Geol.

Soc. Am. Bull., 112, 324-350.

Hodges, K.V., J.M. Hurtado, and K.X. Whipple (2001), Southward extrusion of Tibetan crust

and its effect on Himalayan tectonics, Tectonics, 20, 799-809.

95

Hodges, K.V. (2003), Geochronology and thermochronology in orogenic systems. In Treatise on

Geochemistry, ed. KK Turekian, HD Holland, 263–92. Oxford, UK: Elsevier.

Hooke, R. and N. Iverson (1995), Grain-size distribution in deforming sub-glacial tills: role of

grain fracture, Geology, 23, 57-60.

Huntington, K., A.E. Blythe, and K.V. Hodges (2006), Climate change and Late Pliocene

acceleration of erosion in the Himalaya, Earth Planet. Sci. Lett., 252, 107-118.

Huntoon, P.W. (1993), Influence of inherited Precambrian basement structure on the localization

and form of Laramide monoclines, Grand Canyon, Arizona, in Laramide Basement

Deformation in the Rocky Mountain Foreland of the Western United States, edited by C.J.

Schmidt, R.B. Chase, and E.A. Erslev, Spec. Pap. Geol. Soc. Am., 280, 243-256.

Hurford, A.J., and P.F. Green, (1982), A user’s guide to fission track dating calibration, Earth

and Planetary Science Letters, 59, 343–354, doi:10.1016/0012-821X(82)90136-4.

Hurford, A. J., and P. F. Green (1983), The zeta-age calibration of fission track dating, Isot.

Geosci., 1(4), 285–317.

Iaffaldano, G., L. Husson, and H.P. Bunge (2011), Monsoon speeds up Indian plate motion,

Earth Planet. Sci. Lett., 304, 503-510.

Issen, K.A., and J.W. Rudnicki (2000), Conditions for compaction bands in porous rock, Journal

of Geophysical Research, 105, 21529-21536.

Jain, A.K. (1972), Structure of Bidhalna-Pharat windows and Garhwal thrust unit, Garhwal, U.P,

Himalayan Geology, 2, 188-205.

Jain, A.K., and A. Anand (1988), Deformational and strain patterns of an intracontinental

collision ductile shear zone; an example from the Higher Garhwal Himalaya, J. Struct.

Geol., 10, 717-734.

Jain, A.K., D. Kumar, S. Singh, A. Kumar, and N. Lal (2000), Timing, quantifi cation and

tectonic modelling of Pliocene-Quaternary movements in the NW Himalaya: Evidence

from fission track dating, Earth Planet. Sci. Lett., 179, 437-451.

Jamison, W.R. (1979), Laramide deformation of the Wingate Sandstone, Colorado National

Monument: A study of cataclastic flow, PhD thesis, Texas A&M University, 170p.

Jamison, W.R. (1989), Fault-fracture strain in Wingate sandstone, Journal of Structural Geology,

11, 959-974.

Jamison, W.R., and D.W. Stearns (1982), Tectonic deformation of Wingate sandstone, Colorado

National Monument, AAPG Bulletin, 66, 2584-2608.

96

Jessup, M.J., D.L. Newell, J.M. Cottle, A.L. Berger, and J.A. Spotila (2008), Orogen-parallel

extension and exhumation enhanced by denudation in the trans-Himalayan Arun River

gorge, Ama Drime Massif, Tibet-Nepal, Geology, 36, 587-590.

Jonckheere, R., L. Ratschbacher, and G.A. Wagner, (2003), A repositioning technique for

counting induced fission tracks in muscovite external detectors in single-grain dating of

minerals with low and inhomogeneous uranium concentrations, Radiation Measurements,

37, 217–219, doi:10.1016/S1350-4487(03)00029-5.

Jonckheere, R., E. Enkelmann, M. Min, C. Trautmann, and L. Ratschbacher, 2007, Confined

fission tracks in ion-irradiated and step-etched prismatic sections of Durango apatite,

Chemical Geology, 242, 202–217, doi:10.1016/j.chemgeo.2007.03.015.

Jourde, H., E.A. Flodin, A. Aydin, L.J. Durlofsky, and X. Wen (2002), Computing permeabilities

of fault zones in eolian sandstone from outcrop measurements, AAPG Bulletin, 86, 1187-

1200.

Karlstrom, K.E., and E.D. Humphreys (1998), Persistent influence of Proterozoic accretionary

boundaries in the tectonic evolution of southwestern North America: Interaction of

cratonic grain and mantle modification events, Rocky Mountain Geology, 33, 161-179.

Katz, Y., R. Weinberger, and A. Aydin (2004), Geometry and kinematic evolution of Riedel

shear structures, Capitol Reef National Park, Utah, Journal of Structural Geology, 26,

491-501.

Kellett, D.A., and D. Grujic, (2012), New insight into the South Tibetan detachment system: Not

a single progressive deformation, Tectonics, 31, TC2007, doi: 10.1029/2011TC002957.

Kelley, V. (1955), Regional tectonics of the Colorado Plateau and relationship to the origin and

distribution of Uranium, Univ. N. M. Publ., 5.

Kellogg, K.S., C.J. Schmidt, and S.W. Young (1995), Basement and cover-rock deformation

during Laramide contraction in the northern Madison Range (Montana) and its influence

on Cenozoic basin formation, AAPG Bulletin, 79, 1117-1137.

Ketcham, R.A. (2005), Forward and inverse modeling of low-temperature thermochronometry

data, Rev. Mineral Geochem., 58, 275-314.

Klimczak, C., R. Soliva, R.A. Schultz, and J. Chery (2011), Sequential growth of deformation

bands in a multilayer sequence, Journal of Geophysical Research, 116, B09209.

Kluth, D.F., and P.J. Coney (1981), Plate tectonics of the Ancestral Rocky Mountains, Geology,

9, 10-15.

Kluth, C.F., and H.R. DuChene, (2009), Late Pennsylvanian and Early Permian structural

geology and tectonic history of the Paradox Basin and Uncompahgre Uplift, Colorado

and Utah, in Houston et al., The Paradox Basin Revisited – New Developments in

Petroleum Systems and Basin Analysis, RMAG Special Publication,178-197.

97

Knott, S.D. (1993), Fault seal analysis in the North Sea, AAPG Bulletin, 77, 778-792.

Kocurek, Gary, and R.H.Jr. Dott (1983), Jurassic paleogeography and paleoclimate of the central

and southern Rocky Mountains region, in Reynolds, M.W., and Dolly, E.D., eds.,

Mesozoic Paleogeography of the West-Central United States, Rocky Mountain

Paleogeography, Symposium 2: Denver, Colo., Rocky Mountain Section, Society of

Economic Paleontologists and Mineralogists, 101–116.

Kohn, M. J., S. K. Pau, and S. L. Corrie (2010), The lower Lesser Himalayan sequence: A

Paleoproterozoic arc on the northern margin of the Indian plate, Geol. Soc. Am. Bull., 122,

323-335.

Konstantinovskaia, E., and J. Malavieille (2005), Erosion and exhumation in accretionary

orogens: Experimental and geological approaches, Geochem. Geophy. Geosys., 6,

Q02006, doi: 10.1029/2004GC000794.

Konstantinovskaya E., and J. Malavieille (2011), Thrust wedges with décollement levels and

syntectonic erosion: A view from analog models, Tectonophysics, 502, 336-350.

Kumar, A., N. Lal, A.K. Jain, and R.B. Sorkhabi (1995), Late Cenozoic-Quaternary thermo-

tectonic history of Higher Himalayan Crystalline (Hhc) in Kishtwar–Padar–Zanskar

region, NW Himalaya-evidence from fission-track ages, J. Geol. Soc. India, 45, 375-391.

Lavé, J., and J. P. Avouac (2000), Active folding of fluvial terraces across the Siwaliks Hills,

Himalayas of central Nepal, J. Geophys. Res., 105, 5735-5770.

Le Fort, P. (1975), Himalayas: The collided range. Present knowledge of the continental arc, Am.

J. Sci., 275, 1-44.

Le Fort, P. (1996), Evolution of the Himalaya, in A. Yin, and T.M. Harrison, eds., The tectonics

of Asia, New York, Cambridge University Press, 95-109.

Leger, R.M., A.A.G. Webb, D.J. Henry, J.A. Craig, and P. Dubey (2013), Metamorphic field

gradients across the Himachal Himalaya, northwest India: Implications for the

emplacement of the Himalayan crystalline core, Tectonics, 32, 540-557.

Long, S., N. McQuarrie, T. Tobgay, and D. Grujic (2011), Geometry and crustal shortening of

the Himalayan fold-thrust belt, eastern and central Bhutan, Geological Society of

America Bulletin, 123, 1427-1447.

Lothe, A.E., R.H. Gabrielsen, N. Bjørnevoll-Hagen, and B.T. Larsen (2002), An experimental

study of the texture of deformation bands; effects on the porosity and permeability of

sandstones, Petroleum Geoscience, 8, 195-207.

Lyon-Caen H. and P. Molnar (1985), Gravity anomalies, flexure of the Indian Plate, and the

structure, support and evolution of the Himalaya and Ganga Basin, Tectonics, 4, 513-538.

98

Main, I.G., O. Kwon, B.T. Ngwenya, and S.C. Elphick (2000), Fault sealing during deformation-

band growth in porous sandstone, Geology, 28, 1131-1134.

Malavieille, J. (2010), Impact of erosion, sedimentation, and structural heritage on the structure

and kinematics of orogenic wedges: Analog models and case studies, GSA Today, 20, 4-

10.

Mandl, G., L. N. de Jong, and A. Maltha, (1977), Shear zones in granular material: An

experimental study of their structure and mechanical genesis, Rock Mechanics, 9, 95-144.

Manickavasagam, R. M., A. K. Jain, S. Singh, and A. Asokan (1999), Metamorphic evolution of

the northwest Himalaya, India: Pressure-temperature data, inverted metamorphism, and

exhumation in the Kashmir,Himachal, and Garhwal Himalayas, in Himalaya and Tibet:

Mountain Roots to Mountain Tops, edited by A. Macfarlane, R. B. Sorkhabi, and J.

Quade, Spec. Pap. Geol. Soc. Am., 328, 179 -198.

Marshak, S., and T. Paulsen (1996), Midcontinent U.S. fault and fold zones: A legacy of

Proterozoic intracratonic extensional tectonism? Geology, 24, 151-154.

Marshak, S., K. Karlstrom, and J.M. Timmons (2000), Inversion of Proterozoic extensional

faults: An explanation for the pattern of Laramide and Ancestral Rockies intracratonic

deformation, United States, Geology, 28, 735-738.

McDermott, J.A., K.X. Whipple, K.V. Hodges and M.C.V. Soest (2013), Evidence for Plio-

Pleistocene north-south extension at the southern margin of the Tibetan Plateau, Nyalam

region, Tectonics, 32, 317-333.

McKenzie, N.R., Hughes, N.C., Myrow, P.M., Xiao, S., and Sharma, M (2011), Correlation of

Precambrian Cambrian sedimentary successions across northern India and the utility of

isotopic signatures of Himalayan lithotectonic zones, Earth Planet. Sci. Lett., 312, 471-

483.

McMillan, M.E., P.L. Heller, S.L. Wing (2006), History and causes of post-Laramide relief in

the Rocky Mountain orogenic plateau, GSA Bulletin, 118, 393-405.

McQuarrie, N., D. Robinson, S. Long, T. Tobgay, D. Grujic, G. Gehrels, and M. Ducea (2008),

Preliminary stratigraphic and structural architecture of Bhutan: Implications for the along

strike architecture of the Himalayan system, Earth Planet. Sci. Lett., 272, 105-117.

McQuarrie N., T. Tobgay, S.P. Long, P.W. Reiners and M.A. Cosca (2014), Variable

exhumation rates and variable displacement rates: Documenting recent slowing of

Himalayan shortening in western Bhutan, Earth Planet. Sci. Lett., 386, 161-174.

Meigs, A., D.W. Burbank, and R.A. Beck (1995), Middle–late Miocene (>10 Ma) formation of

the Main Boundary Thrust in the western Himalaya, Geology, 23, 423-426.

99

Miller, C., U. Klotzli, W. Frank, M. Thoni, and B. Grasemann (2000), Proterozoic crustal

evolution in the NW Himalaya (India) as recorded by circa 1.80 Ga mafic and 1.84 Ga

granitic magmatism, Precambrian Research, 103, 191-206.

Mitra, G., K. Bhattacharyya, and M. Mukul (2010), The Lesser Himalayan Duplex in Sikkim:

Implications for variations in Himalayan shortening, J. Geol. Soc. India, 75, 289-301.

Mollema, P.N. and M.A. Antonellini (1996) Compaction bands: a structural analog for anti-

mode I cracks in aeolian sandstone, Tectonophysics, 267, 209-228.

Montgomery D.R., and D.B. Stolar (2006), Reconsidering Himalayan river anticlines,

Geomorphology, 82, 4-15.

Murphy, M.A., J.E. Saylor, and L. Ding (2009), Late Miocene topographic inversion in

southwest Tibet based on integrated paleoelevation reconstructions and structural history,

Earth Planet. Sci. Lett., 282, 1-9.

Myrow, P.M., N.C. Hughes, T.S. Paulsen, I.S. Willlams, S.K. Parcha, K.R. Thompson, S.A.

Bowring, S.C. Peng, and A.D. Ahluwalia (2003), Integrated tectonostratigraphic analysis

of the Himalaya and implications for its tectonic reconstruction, Earth Planet. Sci. Lett.,

212, 433-441.

Nabelek, J., G. Hetenyi, J. Vergne, S. Sapkota, B. Kafle, M. Jiang, H. Su, J. Chen, B.S. Huang,

and the Hi-CLIMB Team (2009), Underplating in the Himalaya-Tibet collision zone

revealed by the Hi-CLIMB experiment, Science, 325, 1371-1374.

Nelson, K.D., et al. (1996), Partially molten middle crust beneath southern Tibet: Synthesis of

project INDEPTH results, Science, 274, 1684-1688.

Ngwenya, B.T., S.C. Elphick, I.G. Main, and G.B. Shimmield (2000), Experimental constraints

on the diagenetic self-sealing capacity of faults in high porosity rocks, Earth Planet. Sci.

Lett., 183, 187-199.

Olierook, H.H., N.E., Timms, and P.J. Hamilton (2014), Mechanisms for permeability

modification in the damage zone of a normal fault, northern Perth Basin, Western

Australia, Marine and Petroleum Geology, 50, 130-147.

Pandey, M.R., R.P. Tandukar, J.P. Avouac, J. Lave, and J.P., Massot (1995), Interseismic strain

accumulation on the Himalayan crustal ramp (Nepal), Geophys. Res. Lett., 22, 751-754.

Patel, R.C., Y. Kumar, N. Lal, and A. Kumar (2007), Thermotectonic history of the Chiplakot

Crystalline Belt in the Lesser Himalaya, Kumaon, India: Constraints from apatite fission-

track thermochronology, J. Asian Earth Sci., 29, 430-439.

Patel, R.C., and A. Carter (2009), Exhumation history of the Higher Himalayan Crystalline along

Dhauliganga-Goriganga river valleys, NW India: New constraints from fission track

analysis, Tectonics, 28, TC3004, doi: 10.1029/2008TC002373.

100

Patel, R.C., V. Adlakha, N. Lal, P. Singh, and Y. Kumar (2011), Spatiotemporal variation in

exhumation of the Crystallines in the NW-Himalaya, India: Constraints from fission track

dating analysis, Tectonophysics, 504, 1-13.

Peterson, Fred (1988), Stratigraphy and nomenclature of Middle and Upper Jurassic rocks,

western Colorado Plateau, Utah and Arizona, in Revisions to stratigraphic nomenclature

of Jurassic and Cretaceous rocks of the Colorado Plateau, U.S. Geological Survey

Bulletin, 1633–B, 17–56.

Peterson, Fred, and C.E. Turner (1998), Stratigraphy of the Ralston Creek and Morrison

Formations (Upper Jurassic) near Denver, Colorado, Modern Geology, 22, 3–38.

Pearson, O.N., and P.G. DeCelles (2005), Structural geology and regional tectonic significance

of the Ramgarh thrust, Himalayan fold-thrust belt of Nepal, Tectonics, 24, TC4008, doi:

10.1029/2003TC001617.

Pilgrim, G.E., and W.D. West (1928), The structure and correlation of the of the Simla rocks,

Geological Survey of India Memoirs, 53, 1-140.

Pipiringos, G.N., and R.B. O’Sullivan, (1978), Principal unconformities in Triassic and Jurassic

rocks, Western Interior United States—A preliminary survey: U.S. Geological Survey

Professional Paper 1035–A, 29 p.

Pittman, E.D. (1981), Effect of fault-related granulation on porosity and permeability of quartz

sandstones, Simpson Group (Ordovician), Oklahoma, AAPG Bulletin, 65, 2381-2387.

Powers, P.M., R.J. Lillie, and R.S. Yeats (1998), Structure and shortening of the Kangra and

Dehra Dun reentrants, Sub-Himalaya, India, GSA Bulletin, 110, 1010-1027.

Price, P.B., and R.M. Walker (1963), Fossil tracks of charged particles in mica and the age of

minerals, J. Geophys. Res., 68, 4847-4862

Raha, P.K., and M.V.A. Sastry (1982), Stromatolites and Precambrian stratigraphy in India,

Precambrian Research, 18, 293-318.

Rahl, J.M., T.A. Ehlers, and B.A. van der Pluijm (2007), Quantifying transient erosion of

orogens with detrital thermochronology from syntectonic basin deposits, Earth Planet.

Sci. Lett., 256, 147-161.

Rai, S.S., K. Priestley, V.K. Gaur, S. Mitra, M.P. Singh, and M. Searle (2006), Configuration of

the Indian Moho beneath the NW Himalaya and Ladakh, Geophys. Res. Lett., 33, L15308.

Reiners, P.W., and M.T. Brandon (2006), Using thermochronology to understand orogenic

erosion, Annual Review of Earth and Planetary Sciences, 34, 419–466,

doi:10.1146/annurev.earth.34.031405.125202.

101

Richards, A., T. Argles, N. Harris, R. R. Parrish, T. Ahmad, F. Darbyshire, and E. Draganits

(2005), Himalayan architecture constrained by isotopic tracers from clastic sediments,

Earth Planet. Sci. Lett., 236, 773-796.

Robinson, D.M. (2008), Forward modeling the kinematic sequence of the central Himalayan

thrust belt, western Nepal, Geosphere, 4, 785-801.

Robinson, D.M., P.G. DeCelles, C.N. Garzione, O.N. Pearson, T.M. Harrison, and E.J. Catlos

(2003), Kinematic model for the Main Central Thrust in Nepal, Geology, 31, 359-362.

Robinson, D.M., P.G. DeCelles, and P. Copeland (2006), Tectonic evolution of the Himalayan

thrust belt in western Nepal: Implications for channel flow models, Geol. Soc. Am. Bull.,

118, 865-885.

Robl, J., K. Stuwe, and S. Hergarten (2008), Channel profiles around Himalayan river anticlines:

Constraints on their formation from digital elevation model analysis, Tectonics, 27, doi:

10.1029/2007TC002215.

Rotevatn, A., A. Torabi, H. Fossen, and A. Braathen (2008), Slipped deformation bands: A new

type of cataclastic deformation bands in Western Sinai, Suez rift, Egypt, Journal of

Structural Geology, 30, 1317-1331.

Royden, L.H., B.C. Burchfiel, and R.D. van der Hilst (2008), The Geological Evolution of the

Tibetan Plateau, Science, 321, 1054-1058.

Rupke, J. (1974), Stratigraphic and structural evolution of the Kumaon Lesser Himalaya:

Sedimentary Geology, 11, 81-265.

Saillet, E., and C.A.J. Wibberley (2013), Permeability and flow impact of faults and deformation

bands in high-porosity sand reservoirs: Southeast Basin, France, analog, AAPG Bulletin,

97, 437-464.

Schelling, D., and K. Arita (1991), Thrust tectonics, crustal shortening, and the structure of the

far eastern Nepal, Himalaya, Tectonics, 10, 851-862.

Scherler, D., B. Bookhagen, and M.R. Strecker (2014), Tectonic control on 10Be-derived erosion

rates in the Garhwal Himalaya, India, J. Geophys. Res., 119, 83-105.

Schlup, M., A. Carter, M. Cosca and A. Steck (2003), Exhumation history of eastern Ladakh

revealed by 40Ar/39Ar and fission-track ages: the Indus River-Tso Morari transect, NW

Himalaya, Journal of the Geological Society, 160, 385-399.

Schmidt, C.J., P.W. Genovese, and R.B. Chase (1993), Role of basement fabric and cover-rock

lithology on the geometry and kinematics of twelve folds in the Rocky Mountain foreland,

in C.J. Schmidt, R.B. Chase, and E.A. Erslev, eds., Laramide basement deformation in

the Rocky Mountain foreland of the western United States: Geological Society of

America Special Paper, 280, 1-44.

102

Schueller, S., A. Braathen, H. Fossen, and J. Tveranger (2013), Spatial distribution of

deformation bands in damage zones of extensional faults in porous sandstones: Statistical

analysis of field data, Journal of Structural Geology, 52, 148-162.

Schultz, R.A. (2009), Scaling and paleodepth of compaction bands, Nevada and Utah, Journal of

Geophysical Research, 114, B03407, doi: 10.1029/2008JB005876.

Schultz, R.A., C.H. Okubo, H. Fossen (2010), Porosity and grain size controls on compaction

band formation in Jurassic Navajo Sandstone. Geophys. Res. Lett. 37, L22306

2010GL044909.

Scott, R.B., A.E. Harding, W.C. Hood, R.D. Cole, R.F. Livaccari, J.B. Johnson, R.R. Shroba,

and R.P. Dickerson (2001), Geological map of Colorado National Monument and

adjacent areas, Mesa County, Colorado, Geologic Investigations Series I-2740, 40 p.

Searle, M.P., R.D. Law, L. Godin, K.P. Larson, M.J. Struele, J.M. Cottle, and M.J. Jessup (2008),

Defining the Himalayan main central thrust in Nepal, J. Geol. Soc, London, 165, 523–534.

Sharma, V.P. (1977), Geology of the Kulu-Rampur belt, Himachal Pradesh, Geological Survey

of India Memoirs, 106, 235-407.

Shipton, Z.K., and P.A. Cowie (2001), Analysis of three-dimensional damage zone development

over um to km scale range in the high-porosity Navajo sandstone, Utah, Journal of

Structural Geology, 23, 1825-1844.

Shipton, Z.K., J.P. Evans, K. Robeson, C.B. Forster, and S. Snelgrove (2002), Structural

heterogeneity and permeability in faulted eolian sandstone: implications for subsurface

modelling of faults, AAPG Bulletin, 86, 863-883.

Shipton, Z.K., J.P. Evans, and L.B. Thompson (2005), The geometry and thickness of

deformation-band fault core and its influence on sealing characteristics of deformation-

band fault zones, AAPG Memoirs, 85, 181-195.

Singh, P., R.C. Patel, and N. Lal (2012), Plio-Plistocene in-sequence thrust propagation along the

Main Central Thrust zone (Kumaon-Garhwal Himalaya, India): New

thermochronological data, Tectonophysics, 574-575, 193-203.

Soliva, R., R.A., Schultz, R.A., G. Ballas, A. Taboada, C. Wibberley, E. Saillet, and A.

Benedicto (2013), A model of strain localization in porous sandstone as a function of

tectonic setting, burial and material properties; new insight from Provence (southern

France), Journal of Structural Geology, 49, 50-63.

Solum, J., J.P. Brandenburg, S.J. Naruk, O. Kostenko, S. Wilkins, and R. Schultz (2010),

Characterization of deformation bands associated with normal and thrust stress states in

the Navajo Sandstone, western U.S.A., AAPG Bulletin, 94, 1453-1475.

Srikantia, S.V., and R.P. Sharma (1976), Geology of the Shali Belt and the adjoining areas,

Memoirs of the Geological Survey of India, 106, 31-66.

103

Srikantia, S.V., and O.N. Bhargava (1988), The Jutogh Group of metasediments of the Himachal

Himalaya; its lithostratigraphy, Geological Society of India Journal, 32, 279-294.

Srivastava, P., and G. Mitra (1994), Thrust geometries and deep structure of the outer and lesser

Himalaya, Kumaon and Garhwal (India): Implications for evolution of the Himalayan

fold-and-thrust belt, Tectonics, 13, 89-109.

Srivastava, P., and S. SKumar (2003), New microfossils from the Meso-Neoproterozoic Deoban

Limestone, Garhwal Lesser Himalaya, India, Palaeobotanist, 52, 13-47.

Stearns, D.W., and W.R. Jamison (1977), Deformation of sandstones over basement uplifts,

Colorado National Monument, Rocky Mountain Association of Geologists, 31-39.

Sternlof, K.R., J.R. Chapin, D.D. Pollard, and L.J. Durlofsky (2004), Permeability effects of

deformation band arrays in sandstone, AAPG Bulletin, 88, 1315-1329.

Sternlof, K.R., J.W. Rudnicki, and D.D. Pollard (2005), Anticrack inclusion model for

compaction bands in sandstone, Journal of Geophysical Research, 110, B11403, doi:

10.1029/2005JB003764.

Steven, T.A., E. Evanoff, and R.H. Yuhas (1997), Middle and late Cenozoic tectonic and

geomorphic development of the Front Range of Colorado, in Bolyard, D.W., and S.A.

Sonnenberg, eds., Geologic history of the Colorado Front Range: Rocky Mountain

Association of Geologists, 115-124.

Stipp, M., H. Stunitz, R. Heilbronner, and S.M. Schmid (2002), The eastern Tonale Fault zone:

‘natural laboratory’ for crystal plastic deformation of quartz over a temperature range

from 250 to 700 °C, J. Struc. Geol., 24, 1861-1884.

Stockmal, G.S., C. Beaumont, M. Nguyen, and B. Lee (2007), Mechanics of thin-skinned fold-

and-thrust belts: Insights from numerical models, in: Sears, J.W., T.A. Harms, C.A.

Evenchick, eds., Whence the Mountains? Inquiries into the Evolution of Orogenic

Systems: A volume in Honor of Raymond A. Price, Geological Society of America

Special Paper, 433, 63-98.

Stone, D.S. (1977), Tectonic history of the Uncompahgre Uplift, in: Veal, H.K., ed., Exploration

frontiers of the central and southern Rockies, Rocky Mountain Association of Geologists

1977 Symposium, 23-30.

Styron, R.H., M.H. Taylor, and M.A. Murphy (2011), Oblique convergence, arc-parallel

extension, and the role of strike-slip faulting in the High Himalaya, Geosphere, 7, 582-

596.

Suppe, J., 1983, Geometry and kinematics of fault-bend folding, American Journal of Science,

283, 684-721.

Suppe, J., and D.A. Medwedeff (1990), Geometry and kinematics of fault-propagation folding,

Eclogae Geologicae Helvetiae, 83, 409-454.

104

Tagami, T., (2005), Zircon fission-track thermochronology and applications to fault studies, Rev

Mineral Geochem., 58, 95-122.

Tagami, T., and P.B. O’Sullivan (2005), Fundamentals of fission-track thermochronology, Rev

Mineral Geochem., 58, 19-47.

Taylor, W.L., and D.D. Pollard (2000), Estimation of in situ permeability of deformation bands

in porous sandstone, Valley of Fire, Nevada, Water Resources Research, 36, 2595-2606.

Tewari, V.C. (2003), Correlation and palaeobiology of Vindhyan and Lesser Himalayan

stratigraphic successions, Palaeontological Society of India Journal, 48, 155-165.

Thiede, R.C. and T.A. Ehlers (2013), Large spatial and temporal variations in Himalayan

denudation, Earth Planet. Sci. Lett., 371-372, 278-293.

Thiede, R.C., B. Bookhagen, J.R. Arrowsmith, E.R. Sobel, and M.R. Strecker (2004), Climatic

control on rapid exhumation along the Southern Himalayan Front, Earth Planet. Sci. Lett.,

222, 791-806.

Thiede, R.C., J.R. Arrowsmith, B. Bookhagen, M.O. McWilliams, E.R. Sobel, and M.R. Strecker

(2005), From tectonically to erosionally controlled development of the Himalayan fold-

and-thrust belt, Geology, 33, 689-692.

Thiede, R.C., T.A. Ehlers, B. Bookhagen, and M.R. Strecker (2009), Erosional variability along

the northwest Himalaya, J. Geophys. Res., 114, doi: 10.1029/2008JF001010.

Timmons, J.M., K.E. Karlstrom, C.M. Dehler, J.W. Geissman, and M.T. Heizler (2001),

Proterozoic multistage (ca. 1.1 and ca. 0.8 Ga) extension recorded in the Grand Canyon

Supergroup and establishment of northwest- and north-trending tectonic grains in the

southwestern United States, Geological Society of American Bulletin, 113, 163-181.

Timmons, J., K. Karlstrom, J. Pederson, M. Anders, and R. Taylor (2007), Geologic map of the

Butte fault/East Kaibab monocline area, eastern Grand Canyon, Arizona, Grand Canyon

Association of New Mexico and the New Mexico Bureau of Geology and Mineral

Resources ISBN-13, 978-0-938216-91-9, Socorro, New Mexico, scale 1:24,000, 2 sheets.

Tindall, S.E., and Davis, G.H. (1999), Monocline development by oblique-slip fault propagation

folding: the East Kaibab monocline, Colorado Plateau, Utah, Journal of Structural

Geology, 21, 1303-1320.

Torabi, A., and H. Fossen (2009), Spatial variation of microstructure and petrophysical

properties along deformation bands in reservoir sandstones, AAPG Bulletin, 93, 919-938.

Trivedi, J.R., K. Gopalan, and K.S. Valdiya (1984), Rb-Sr ages of granitic rocks within the

Lesser Himalayan Nappes, Kumaun, India, Geological Society of India Journal, 25, 641-

654.

105

Upreti, B.N. (1999), An overview of the stratigraphy and tectonics of the Nepal Himalaya, J.

Asian Earth Sci., 17, 577-606.

Valdiya, K.S. (1980), Geology of Kumaun Lesser Himalaya, Dehra Dun, India, Wadia Institute

of Himalayan Geology.

Vance, D., M. Bickle, S. Ivy-Ochs, and P.W. Kubik (2003), Erosion and exhumation in the

Himalaya from cosmogenic isotope inventories of river sediments, Earth Planet. Sci.

Lett., 206, 273-288.

Vannay, J.C., and B. Grasemann (1998), Inverted metamorphism in the High Himalaya of

Himachal Pradesh (NW India): Phase equilibria versus thermobarometry, Schweizerische

Mineralogische und Petrographische Mitteilungen, 78, 107-132.

Vannay, J. C., B. Grasemann, M. Rahn, W. Frank, A. Carter, V. Baudraz, and M. Cosca (2004),

Miocene to Holocene exhumation of metamorphic crustal wedges in the NW Himalaya:

Evidence for tectonic extrusion coupled to fluvial erosion, Tectonics, 23, TC1014,

doi:10.1029/ 2002TC001429.

Wang, B., Y. Chen, and T.-F. Wong (2008), A discrete element model for the development of

compaction localization in granular rock, J. Geophys. Res., 113, B03202, doi:

10.1029/2006JB004501.

Wang, P.K., S. Clemens, L. Beaufort, P. Braconnot, G. Ganssen, Z. Jian, P. Kershaw, and M.

Sarnthein (2005), Evolution and variability of the Asian monsoon system: state of the art

and outstanding issues, Q. Sci. Rev., 24, 595-629.

Webb, A.A.G. (2013), Preliminary balanced palinspastic reconstruction of Cenozoic deformation

across the Himachal Himalaya (northwestern India), Geosphere, 9, 572-587.

Webb, A.A.G., A. Yin, T.M. Harrison, J. Célérier, and W.P. Burgess (2007), The leading edge of

the Greater Himalayan Crystallines revealed in the NW Indian Himalaya: Implications

for the evolution of the Himalayan Orogen, Geology, 35, 955-958.

Webb, A.A.G., A. Yin, T.M. Harrison, J. Célérier, G.E. Gehrels, C.E. Manning, and M. Grove

(2011a), Cenozoic tectonic history of the Himachal Himalaya (northwestern India) and its

constraints on the formation mechanism of the Himalayan orogeny, Geosphere, 7, 1013-

1061.

Webb, A.A.G., A.K. Schmitt, D. He, and E.L. Weigand (2011b), Structural and

geochronological evidence for the leading edge of the Greater Himalayan Crystalline

complex in the central Nepal Himalaya, Earth Planet. Sci. Lett., 304, 483-495.

Webb, A.A.G., A. Yin, and C.S. Dubey (2013), U-Pb zircon geochronology of major lithologic

units in the Eastern Himalaya: Implications for the origin and assembly of Himalayan

rocks, Geol. Soc. Am. Bull., 125, 499-522.

106

Wennberg, O.P., G. Casini, A. Jahanpanah, F. Lapponi, J. Ineson, B.G. Wall, and P. Gillespie

(2013), Deformation bands in chalk, examples from the Shetland Group of the Oseberg

Field, North Sea, Norway, Journal of Structural Geology, 56, 103-117.

West, W.D. (1939), The structure of the Shali Window near Simla, Geological Survey of India

Records, 74, 133-163

Whipp, D.M.(Jr), T.A. Ehlers, A.E. Blythe, K.W. Huntington, K.V. Hodges, and D. Burbank

(2007), Plio-Quaternary exhumation history of the central Nepalese Himalya; 2,

Thermokinematic and thermochronometer age prediction model, Tectonics, 26,

doi:10.1029/2006TC001991.

White, M.A. and M.I. Jacobson (1983), Structures associated with the southwest margin of the

ancestral Uncompahgre Uplift. In: North Paradox basin-Uncompahgre Uplift (Ed. By

W.R. Averett), 33-39. Grand Junction Geol. Soc

Whitmeyer, S.J., and K.E. Karlstrom (2007), Tectonic model for the Proterozoic growth of North

America, Geosphere, 3, 220-259.

Wibberley, C.A.J., J.-P. Petit, T. Rives (2007), The mechanics of fault distribution and

localization in high-porosity sands, Provence, France, in: Lewis, H., G.D. Couples, eds.,

The Relationship between Damage and Localization, Geological Society, London,

Special Publications, 164, 599-608.

Wiesmayr, G., and B. Grasemann (2002), Eohimalayan fold and thrust belt: Implications for the

geodynamic evolution of the NW-Himalaya (India), Tectonics, 21, 1058-1074.

Wobus, C.W., K.V. Hodges, and K.X., Whipple (2003), Has focused denudation sustained active

thrusting at the Himalayan topographic front? Geology, 31, 861-864.

Wobus, C., A. Heimsath, K. Whipple, and K. Hodges (2005), Active out-of-sequence thrust

faulting in the central Nepalese Himalaya, Nature, 434, 1008-1011.

Wobus, C.W., K.X. Whipple, and K.V. Hodges (2006), Neotectonics of the central Nepalese

Himalaya: Constraints from geomorphology, detrital 40

Ar/39

Ar thermochronology, and

thermal modeling, Tectonics, 25, doi: 10.1029/2005TC001935.

Wobus, C., M. Pringle, K. Whipple, and K. Hodges (2008), A Late Miocene acceleration of

exhumation in the Himalayan crystalline core, Earth Planet. Sci. Lett., 269, 1-10.

Wong, T.-f., C. David, and Q. Zhu (1997), The transition from brittle faulting to cataclastic flow

in porous sandstones: mechanical deformation, Journal of Geophysical Research, 102,

3009-3025.

Ye, H., L. Royden, C. Burchfiel, and M. Schuepbach (1996), Late Paleozoic deformation of

interior North America: The greater Ancestral Rocky Mountains, American Association

of Petroleum Geologists Bulletin, 80, 1397-1432.

107

Yin, A. (2006), Cenozoic tectonic evolution of the Himalayan orogen as constrained by along-

strike variation of structural geometry, exhumation history, and foreland sedimentation,

Earth Sci. Rev., 76, 1-131.

Yin, A., and T.M. Harrison (2000), Geologic evolution of the Himalayan-Tibetan orogeny, Ann.

Rev. Earth Planet. Sci, 28, 211-280.

Yin, A., C.S. Dubey, T.K. Kelty, A.A.G. Webb, T.M. Harrison, C.Y. Chou, and J. Célérier

(2010), Geologic correlation of the Himalayan orogen and Indian craton: Part 2.

Structural geology, geochronology, and tectonic evolution of the Eastern Himalaya, Geol.

Soc. Am. Bull., 122, 360-395.

Zeitler P.K., R.A.K. Tahirkheli, C.W. Naeser, and N.M. Johnson NM (1982), Unroofing history

of a suture zone in the Himalaya of Pakistan by means of fission-track annealing ages.

Earth Planet Sci. Lett., 57, 227-240.

Zeitler, P.K., 1985, Cooling history of the northwestern Himalaya, Pakistan, Tectonics, 4, 127-

151.

Zeitler, P.K., P.O. Koons, M.P. Bishop, et al. (2001), Crustal reworking at Nanga Parbat,

Pakistan: metamorphic consequences of thermal–mechanical coupling facilitated by

erosion, Tectonics, 20, 712-728.

108

APPENDIX A: APATITE FISSSION TRACK DATA

Yu91129-6 Pooled age±1σ (Ma) 8.4± 0.4

ζ (Ma)

ρD ± 1σ [106 cm-2]

Longitude (N)

Latitude(E) Elevation(m) Rock type

268±4.7 0.375±0.006 29°48. 522' 78°39 829' 1209 granite gneiss

n Spontaneous track (Ns)

Induced track (Ni)

n Spontaneous track (Ns)

Induced track (Ni)

1 9 83 33 19 146

2 5 33 34 8 32

3 22 180 35 17 115

4 10 75 36 12 56

5 5 64 37 14 61

6 30 235 38 20 146

7 3 32 39 20 79

8 4 37 40 27 168

9 3 12 41 18 248

10 9 45 42 9 74

11 9 63 43 17 101

12 4 74 44 13 137

13 22 83 45 8 74

14 23 131 46 15 98

15 6 27 47 27 133

16 4 17 48 10 51

17 18 108 49 11 71

18 46 116 50 16 86

19 4 26 51 24 131

20 17 37 52 28 168

21 7 53 53 28 166

22 16 76 54 43 260

23 25 111 55 42 150

24 31 173 56 10 62

25 8 104 26 23 131 27 13 54 28 25 133 29 12 108 30 17 47 31 20 101

109

32 19 146

Yu91130-6 Pooled age±1σ (Ma) 6.7± 0.6

ζ (Ma)

ρD ± 1σ [106 cm-2]

Longitude (N)

Latitude(E) Elevation(m) Rock type

268±4.7 0.383±0.006 29°56.057' 78°44.425' 628 sandstone

n Spontaneous track (Ns)

Induced track (Ni)

1 6 64

2 2 25

3 3 40

4 2 25

5 7 54

6 17 180

7 6 91

8 43 299

9 8 48

10 16 109

11 4 39

12 32 141

110

Yu91130-9 Pooled age±1σ (Ma) 6.2± 0.3

ζ (Ma)

ρD ± 1σ [106 cm-2]

Longitude (N)

Latitude(E) Elevation(m) Rock type

268±4.7 0.385±0.006 30°01.930' 78°48.148' 985 quartzite

n Spontaneous track (Ns)

Induced track (Ni)

n Spontaneous track (Ns)

Induced track (Ni)

1 2 28 26 7 66

2 20 93 27 10 46

3 10 55 28 7 55

4 1 18 29 5 19

5 8 50 30 5 55

6 3 14 31 11 92

7 13 79 32 2 28

8 5 21 33 7 86

9 8 67 34 7 33

10 8 32

11 3 17

12 5 59

13 8 55

14 3 33

15 9 51

16 5 56

17 5 50

18 4 21

19 7 93

20 12 63

21 5 42

22 6 79

23 14 79

24 9 111

25 10 51

111

Yu91201-9 Pooled age±1σ (Ma) 3.7± 0.3

ζ (Ma)

ρD ± 1σ [106 cm-2]

Longitude (N)

Latitude(E) Elevation(m) Rock type

268±4.7 0.387±0.006 30°12.097' 78°50.920' 1367 quartzite

n Spontaneous track (Ns)

Induced track (Ni)

n Spontaneous track (Ns)

Induced track (Ni)

1 3 126

2 5 65

3 9 202

4 8 68

5 7 75

6 6 52

7 5 137

8 5 61

9 11 116

10 10 80

11 10 81

12 3 31

13 4 74

14 4 73

15 5 122

16 9 67

17 7 87

18 15 134

19 9 119

20 5 69

21 2 102

22 8 136

23 3 51

112

Yu91208-4 Pooled age±1σ (Ma) 4.0±0.3

ζ (Ma)

ρD ± 1σ [106 cm-2]

Longitude (N)

Latitude(E) Elevation(m) Rock type

268±4.7 0.393±0.006 30°21.526' 79°19.047' 960 Augen gneiss

n Spontaneous track (Ns)

Induced track (Ni)

n Spontaneous track (Ns)

Induced track (Ni)

1 8 175 35 3 56

2 2 23 36 1 23

3 1 34 37 14 104

4 5 36 38 3 40

5 8 82 39 5 42

6 5 52 40 11 112

7 4 115 41 3 52

8 9 68 42 8 188

9 9 56 43 8 95

10 15 185 44 13 168

11 10 56 45 3 42

12 1 49 46 8 54

13 8 79 47 1 29

14 7 126 48 9 125

15 17 331 49 4 64

16 2 55 50 10 73

17 8 94 51 3 48

18 9 168 52 2 52

19 3 36 53 5 100

20 5 56 54 1 29

21 26 145 55 2 39

22 4 37 56 9 139

23 5 30 57 5 72

24 4 22 58 3 61

25 4 86 59 4 80

26 3 20 60 2 36

27 19 220 61 6 78

28 12 97 62 14 261

29 9 78 63 7 75

30 2 40 64 6 70

31 1 15 65 4 80

32 17 129

33 4 32

34 9 75

113

Yu91206-1 Pooled age±1σ (Ma) 1.1±0.04

ζ (Ma)

ρD ± 1σ [106 cm-2]

Longitude (N)

Latitude(E) Elevation(m) Rock type

268±4.7 0.391±0.006 30°33.008' 79°19.047' 1786 granite gneiss

n Spontaneous track (Ns)

Induced track (Ni)

n Spontaneous track (Ns)

Induced track (Ni)

1 14 630

2 33 1600

3 39 1550

4 55 2320

5 20 868

6 37 2519

7 34 1967

8 46 1919

9 84 2593

10 50 2909

11 42 1772

12 50 2345

13 41 1956

14 39 2092

15 38 1326

16 85 4050

17 43 2692

18 38 1820

19 81 4520

20 66 3276

21 51 1767

22 62 2969

23 104 5741

24 47 2542

25 28 1996

114

APPENDIX B: ZIRCON FISSSION TRACK DATA

Yu91129-1 Pooled age±1σ (Ma) 119± 13

ζ (Ma)

ρD ± 1σ [106 cm-2]

Longitude (N)

Latitude(E) Elevation(m) Rock type

97.1±2.4 0.280±0.013 29°48. 522' 78°36 861' 763 sandstone

n Spontaneous track (Ns)

Induced track (Ni)

n Spontaneous track (Ns)

Induced track (Ni)

1 630 36 34 219 13

2 117 34 35 179 11

3 114 10 36 232 45

4 66 5 37 535 20

5 94 27 38 153 26

6 77 30 39 275 18

7 135 9 40 120 45

8 155 13 41 380 13

9 242 23 42 181 55

10 150 25 43 431 25

11 141 20 44 1416 40

12 367 30 45 798 38

13 39 8 46 905 21

14 233 17 47 201 57

15 42 13 48 309 39

16 129 10 49 440 68

17 66 21 50 442 17

18 448 21

19 500 37

20 96 20

21 160 11

22 716 18

23 96 10

24 344 13

25 299 26

26 82 7

27 172 33

28 569 20

29 249 10

30 419 37

31 103 10

115

32 319 44

33 333 51

Yu91129-6 Pooled age±1σ (Ma) 28.8± 1.8

ζ (Ma)

ρD ± 1σ [106 cm-2]

Longitude (N)

Latitude(E) Elevation(m) Rock type

97.1±2.4 0.261±0.012 29°48. 522' 78°39 829' 1209 granite gneiss

n Spontaneous track (Ns)

Induced track (Ni)

n Spontaneous track (Ns)

Induced track (Ni)

1 173 72

2 385 250

3 243 130

4 90 62

5 65 67

6 49 18

7 82 37

8 81 40

9 93 48

10 115 20

11 155 74

12 117 32

13 97 20

14 106 86

15 115 31

16 67 14

17 208 40

18 56 12

19 241 69

20 82 30

21 76 34

116

Yu91129-12 Pooled age±1σ (Ma) 26.8± 1.9

ζ (Ma)

ρD ± 1σ [106 cm-2]

Longitude (N)

Latitude(E) Elevation(m) Rock type

97.1±2.4 0.286±0.016 29°53. 280' 78°40 432' 1496 quartzite

n Spontaneous track (Ns)

Induced track (Ni)

n Spontaneous track (Ns)

Induced track (Ni)

1 57 43 26 157 61

2 76 37 27 128 54

3 43 18 28 157 90

4 153 92 29 137 68

5 56 35 30 104 62

6 58 24 31 98 74

7 128 73 32 76 30

8 75 37 33 157 104

9 32 21 34 166 83

10 78 48 35 164 83

11 111 63 36 119 69

12 42 33

13 241 95

14 106 52

15 45 21

16 152 49

17 122 75

18 176 70

19 67 27

20 138 79

21 125 67

22 101 42

23 114 45

24 89 65

25 125 62

117

Yu91130-2 Pooled age±1σ (Ma) 183± 14

ζ (Ma)

ρD ± 1σ [106 cm-2]

Longitude (N)

Latitude(E) Elevation(m) Rock type

97.1±2.4 0.211±0.004 29°54.592' 78°42.767' 768 quartzite

n Spontaneous track (Ns)

Induced track (Ni)

1 346 35

2 816 47

3 806 59

4 530 51

5 441 58

6 1865 156

7 696 28

8 704 36

9 525 27

10 1115 45

11 490 24

12 1145 46

13 1619 51

14 1663 73

15 671 67

16 1704 62

17 633 24

18 519 32

19 2508 126

20 1265 70

21 663 29

22 1545 76

23 651 21

24 956 37

25 1329 60

26 504 18

27 814 41

118

Yu91130-6 Pooled age±1σ (Ma) 177± 18

ζ (Ma)

ρD ± 1σ [106 cm-2]

Longitude (N)

Latitude(E) Elevation(m) Rock type

97.1±2.4 0.283±0.013 29°56.057' 78°44.425' 628 sandstone

n Spontaneous track (Ns)

Induced track (Ni) n

Spontaneous track (Ns)

Induced track (Ni)

1 41 3 37 499 18

2 127 4 38 277 18

3 516 20 39 198 8

4 48 4 40 669 24

5 247 140 41 320 10

6 391 20 42 216 8

7 303 14 43 413 25

8 230 11 44 168 9

9 201 15 45 171 14

10 121 9 46 184 12

11 184 15 47 324 24

12 220 17 48 287 20

13 361 18 49 306 12

14 200 16 50 920 30

15 45 7 51 122 6

16 157 26 52 244 13

17 124 16 53 730 28

18 92 16 54 535 21

19 349 21 55 579 25

20 117 18 56 676 35

21 316 17 57 239 15

22 33 4 58 249 17

23 447 42 59 428 28

24 114 14 60 160 7

25 89 8

27 358 25

28 50 3

29 114 13

30 156 10

31 323 13

32 87 9

33 218 14

34 410 22

35 82 5

36 251 17

119

Yu91130-9 Pooled age±1σ (Ma) 12.5± 0.4

ζ (Ma) ρD ± 1σ [106 cm-2] Longitude (N) Latitude(E) Elevation(m) Rock type

97.1±2.4 0.273±0.015 30°01.930' 78°48.148' 985 quartzite

n Spontaneous track (Ns)

Induced track (Ni)

n Spontaneous track (Ns)

Induced track (Ni)

1 32 22 39 97 109

2 22 28 40 24 27

3 13 19 41 41 31

4 41 27 42 20 30

5 65 80 43 39 47

6 33 35 44 35 33

7 46 34 45 80 54

8 30 27 46 44 51

9 19 28 47 23 37

10 17 23 48 33 37

11 20 25 49 41 54

12 22 28 50 48 40

13 23 20

14 65 44

15 34 39

16 13 26

17 65 78

18 40 50

19 19 25

20 33 24

21 35 32

22 144 126

23 48 51

24 49 43

25 95 81

26 63 79

27 87 76

28 20 20

29 70 80

30 54 83

31 47 108

32 50 49

33 43 36

34 44 81

35 103 100

36 49 66

37 107 76

38 113 116

120

Yu91201-4 Pooled age±1σ (Ma) 12.3± 0.8

ζ (Ma)

ρD ± 1σ [106 cm-2]

Longitude (N)

Latitude(E) Elevation(m) Rock type

97.1±2.4 0.286±0.017 30°07.453' 78°49.458' 1885 quartzite

n Spontaneous track (Ns)

Induced track (Ni)

1 107 136

2 93 147

3 187 139

4 213 227

5 117 129

6 271 181

7 111 120

8 349 400

9 231 185

10 151 156

11 135 155

12 383 308

13 332 371

14 151 184

15 70 77

16 70 61

17 434 534

18 130 155

19 181 204

20 277 335

21 128 155

22 167 215

23 130 136

24 121 131

25 334 279

26 137 217

27 100 115

28 126 159

29 204 306

30 90 110

121

Yu91201-9 Pooled age±1σ (Ma) 9.5± 0.6

ζ (Ma)

ρD ± 1σ [106 cm-2]

Longitude (N)

Latitude(E) Elevation(m) Rock type

97.1±2.4 0.250±0.017 30°12.097' 78°50.920' 1367 quartzite

n Spontaneous track (Ns)

Induced track (Ni)

n Spontaneous track (Ns)

Induced track (Ni)

1 84 124 36 148 204

2 99 103 37 39 62

3 167 201 38 39 53

4 72 136 39 46 53

5 24 47 40 99 126

6 106 125 41 55 68

7 67 68 42 120 147

8 94 128

9 115 150

10 141 177

11 89 138

12 117 149

13 99 151

14 50 113

15 104 175

16 94 121

17 147 159

18 59 88

19 114 161

20 65 111

21 114 186

25 334 279

26 137 217

27 100 115

28 126 159

29 204 306

30 90 110

31 97 132

32 88 108

33 89 115

34 51 81

35 128 158

122

Yu91204-1 Pooled age±1σ (Ma) 4.7± 0.3

ζ (Ma)

ρD ± 1σ [106 cm-2]

Longitude (N)

Latitude(E) Elevation(m) Rock type

97.1±2.4 0.218±0.004 30°14.417' 78°49.647' 616 quartzite

n Spontaneous track (Ns)

Induced track (Ni)

n Spontaneous track (Ns)

Induced track (Ni)

1 26 92

2 26 140

3 28 56

4 39 120

5 25 49

6 35 87

7 46 99

8 51 89

9 22 66

10 53 92

11 36 65

12 40 64

13 29 36

14 30 29

123

Yu91204-9 Pooled age±1σ (Ma) 132± 22

ζ (Ma)

ρD ± 1σ [106 cm-2]

Longitude (N)

Latitude(E) Elevation(m) Rock type

97.1±2.4 0.268±0.014 30°18.330' 79°02.113' 723 quartzite

n Spontaneous track (Ns)

Induced track (Ni)

n Spontaneous track (Ns)

Induced track (Ni)

1 352 45 31 2050 61

2 576 92 32 815 47

3 430 85 33 483 36

4 760 83 34 615 115

5 2280 125 35 2015 74

6 500 56 36 875 51

7 1400 63 37 672 48

8 600 62

9 1260 86

10 82 61

11 1454 66

12 2900 121

13 1200 43

14 900 93

15 2000 112

16 2050 61

17 815 47

18 483 36

19 615 115

20 2015 74

21 875 51

22 672 48

23 600 62

24 1260 86

25 82 61

26 1454 66

27 2900 121

28 1200 43

29 900 93

30 2000 112

124

Yu91209-1 Pooled age±1σ (Ma) 6.0± 0.5

ζ (Ma)

ρD ± 1σ [106 cm-2]

Longitude (N)

Latitude(E) Elevation(m) Rock type

97.1±2.4 0.276±0.014 30°16.593' 79°14.156' 895 quartzite

n Spontaneous track (Ns)

Induced track (Ni)

n Spontaneous track (Ns)

Induced track (Ni)

1 56 107 31 31 55

2 46 96 32 19 46

3 81 175 33 58 143

4 59 103 34 24 79

5 50 154 35 42 180

6 14 36 36 30 56

7 58 149 37 67 178

8 65 128 38 59 122

9 30 60 39 20 55

10 18 34

11 12 60

12 70 158

13 23 52

14 79 233

15 30 64

16 39 103

17 43 125

18 41 116

19 57 106

20 47 59

21 65 121

22 25 75

23 67 133

24 73 89

25 93 253

26 52 133

27 41 74

28 31 75

29 40 67

30 32 71

125

Yu91208-4 Pooled age±1σ (Ma) 5.7± 0.4

ζ (Ma)

ρD ± 1σ [106 cm-2]

Longitude (N)

Latitude(E) Elevation(m) Rock type

97.1±2.4 0.246±0.015 30°21.526' 79°19.047' 960 Augen gneiss

n Spontaneous track (Ns)

Induced track (Ni)

n Spontaneous track (Ns)

Induced track (Ni)

1 32 51

2 39 66

3 42 81

4 64 152

5 40 94

6 42 119

7 62 92

8 89 161

9 21 36

10 46 118

11 29 63

12 33 66

13 19 40

14 39 50

15 15 34

16 48 184

17 42 86

18 32 76

19 38 56

20 57 132

21 26 52

126

Yu91206-1 Pooled age±1σ (Ma) 1.5±0.1

ζ (Ma)

ρD ± 1σ [106 cm-2]

Longitude (N)

Latitude(E) Elevation(m) Rock type

97.1±2.4 0.204±0.005 30°33.008' 79°32.692' 1786 Augen gneiss

n Spontaneous track (Ns)

Induced track (Ni)

n Spontaneous track (Ns)

Induced track (Ni)

1 82 510 21 48 250

2 40 299 22 41 252

3 34 276 23 78 435

4 26 221 24 73 549

5 32 264 25 35 350

6 47 283 26 66 397

7 52 322 27 31 245

8 30 275 28 21 191

9 65 327 29 80 459

10 45 320 30 31 204

11 52 340 31 58 442

12 43 356 32 151 648

13 42 311 33 64 527

14 62 334

15 64 344

16 53 284

17 95 547

18 31 284

19 67 558

20 55 365

21 48 250

22 41 252

23 78 435

24 73 549

25 35 350

26 66 397

27 31 245

28 21 191

29 80 459

30 31 204

127

PLATE 1: SEQUENTIAL CROSS-SECTION RESTORATION ACROSS THE NW INDIAN HIMALAYA

128

VITA

Hongjiao Yu was born in 1983, in Liaoning Province, China. She spent four years at

China University of Petroleum, where she earned a Bachelor of Resources Prospecting

Engineering in 2006. After that, she was offered an opportunity to pursue her study in Peking

University and earned a Master’s degree in geology in 2009. Immediately after the Master’s

study, she was admitted to the Ph.D. program in the structural geology and tectonics group at

Louisiana State University in August, 2009. She has been a research assistant and teaching

assistant for Structural Geology Lab for three years. During her Ph.D. study, she had two

summer internships with Shell Oil Company in 2011 and 2012.