Earth Sciences and Geography, Keele University, Keele, Staffordshire, ST5 5BG, UKOliver Wakefield and Nigel Mountney

Introduction & Study Location

Regional Stratigraphic Setting

Summary Model and Conclusions

Characteristic Lithofacies Examples

Preserved Sedimentary Expression of an Incised Valley-Fill Succession Within a Transgressive Shoreline SystemCutler Group, Paradox Basin, Southeast Utah, USA

o.j.w.wakefield@epsam.keele.ac.uk

+44 (0) 1782 583171

http://www.esci.keele.ac.uk/

100m

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Low

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Cutler

Beds

Cedar

Mesa

Sandsto

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Pennsylv

ania

n-

Low

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Perm

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(Wolfcam

pia

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Little Spring Canyon Sedimentary Logs: Setting Proximal to the Palaeo-Coastline

Little Spring Canyon: Examples of Facies Architecture Lower Indian Creek: Examples of Facies Architecture

Lower Indian Creek Sedimentary Logs: Setting Distal to the Palaeo-Coastline

The study areas arelocated in, and adjacent tothe Needles District ofCanyonlands NationalP a r k , w h e r e t h ecombined effects of bothdeep incision by tributarycanyons of the ColoradoRiver, & gentle anticlinalfolding expose the upperand middle parts of theLower Cutler Beds.

The Lower Cutler Beds of southeastern Utah represents a Pennsylvanian-to-Permian age, mixedcontinental-marine shoreline succession, which accumulated under the influence of a predominantlyarid climatic regime and which was subject to repeated marine transgressive-regressive cycles. Thesuccession - which is

comprises aeolian, fluvial, and shallow marine units that have previously beeninterpreted to have accumulated in a low relief, low gradient coastal plain and shallow marine rampsetting (Jordan, 2006). The aim of this project is to reconstruct the geometry and account for thearchitectural complexity of a series of well exposed incised valley systems that are thought to havebeen cut during episodes of relative sea level fall and then in-filled with a variety of shallow marinefacies during subsequent episodes of relative sea level rise. The valley systems exhibit considerablevariation in their preserved expression over distances of only 10 km, reflecting increased amounts ofincision in close proximity to shoreline regions.

well exposed across much of the northern and central parts of the Paradoxforeland basin -

The two study regions within the Lower Cutler Beds record the style of sediment infillwithin an incised valley complex that likely represents proximal and distal parts of thesame valley system over a distance of 10 km along a transect running inland from theinferred position of the palaeo-coastline. The characteristics of the style of incised valleyback-fill changes dramatically from the more coastline-proximal location at Little SpringCanyon to the more distal locality at Lower Indian Creek. The Calcarenite gritstonechannels thin from thickness of 7-12 m at Little Spring Canyon to < 2 m at Lower IndianCreek. Additionally, the style of sedimentation varieswith Lower Indian Creek exposing thick accumulations of laterally continuous fluvial andaeolian units, which contrasts with a more fragmentary style of preservation at LittleSpring Canyon.

noticeably between each location,

Case Study 1: Little Spring Canyon Case Study 2: Lower Indian Creek

Cedar Mesa Sandstone

Lower CutlerBeds

Photo showing location of Little Spring CanyonLog 1 (red). The prominent massive structurelessunit at one-third height is a large, erosively-basedchannel infilled with calcarentite gritstone andforms part of the thicker marine unit in thecorrelation panel above. Cliff is 60 m high. Thehorizon marked in yellow signifies the top of theuppermost marine limestone that defines the topof the Lower Cutler Beds and the base of theoverlying Cedar Mesa Sandstone. This horizoncan be traced for over 50 km to the north.

Calcarenite gritstone facies, Lower Indian Creek.

Photo showing location of LowerIndian Creek Log 8 (red, 40 m high).Only three thin shallow marine unitsare preserved at this locality andrelief on the base of these units doesnot exceed 1-2 m.

Ae

olia

nF

luvia

lM

arin

e

Aeolian, horiz. bedded

Aeolian, cross bedded

Aeolian, massive

Fluvial, cross bedded

Fluvial, horiz. bedded

Fluvial, mud- & siltstone

Limestone, bedded

Limestone, micritic

Calcarenite gritstone

Gradational facies change

Bioturbation

ClastsBlack = ExtraformationalColoured = Intraformational

Trough-cross bedding

Planar-cross bedding

Horizontal lamination

Shelly debris & fragments

Nodules

Soft sediment deformation

Bioturbated aeolian interdune facies. Cross bedded aeolian dune facies. Tape = 2 m.

Wavy-to-ripple laminated fluvial sandstone facies.Horizontally laminated fluvial siltstone facies.

Trough-cross bedded aeolian dune facies.

Nodular marine limestone facies. Knife = 6 cm.

Fossiliferous, bedded limestone facies.

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100m

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Low

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Cutler

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CanyonlandsNational Park,Needles District

The Lower Cutler Beds exhibit a variety of complex architectural relationships between marine, fluvialand aeolian depositional units. These represent the preserved stratigraphic expression of a marginalmarine, shoreline and arid terrestrial system that was subject to repeated marine transgressive andregressive events. Whilst the marine units, which represent the product of transgressive events, aretypically only 2-5 m thick, in places they infill broad incised valley systems where they attainthicknesses of 12-15 m and exhibit a complex array of facies interactions and architectural styles. Aseries of high-resolution sedimentary logs, measured from two study regions within the Lower CutlerBeds, record the style of sediment infill within an incised valley complex that likely represents shore-proximal and shore-distal parts of the same valley system over a distance of 10 km.

Regional Stratigraphy

Regional palaeogeography

Study Locations

N UTAH

0 5km

Study area 1:Little Spring Canyon

Study area 2:Lower Indian Creek

The extent of the Paradox foreland basin and associatedmajor structural elements in adjacent areas with the studylocality shown. The area in yellow denotes the limits of theParadox Formation salt that defines the extent of the mainbasin. Modified after Kelley (1958), cited in Nuccio andCondon (1996).

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DEFIANCEPLATEAU

CarrizoMtns.

SAN JUANBASIN

UNCOM

PAHGRE

PLATE

AU

SAN RAFAELSWELL

PARADOX

FOLDFAULT

BELT

AND

UINTA BASIN

TYENDESADDLE

BLACKMESABASIN

KAIBITOSADDLE

PIUTEFOLDS

NavajoMtn

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CA

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Henry

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0 25 Mi

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Utah

ArizonaColorado

New Mexico

111 00' 11030' 11000' 10930' 10900' 10830' 10800' 10730'

Durango

Farmington

Hanksville

Hite

Montrose

NavajoReservoir

LakePowell

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Sleeping UteMountain

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COMB

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CLIN

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SanMiguelMtns

La PlataMtns

Green

River

GrandJunction

Gateway

Naturita

Ouray

Cortez

Blanding

Moab

Bluff

SlickRock

Monticello

San JuanRiver

Green

River

Col

orad

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River

MexicanHat

Kayenta

Col

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River

Rico

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RicoMtns

NeedleMtns

OIL

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39 30'

39 00'

38 30'

38 00'

37 30'

37 00'

36 30'

LISBON

VALLEY

ANTIC

LINE Palaeo - windflow

Palaeo - Fluvial

Shafer Basin

Lockhart Basin

Canyonlands

District

Grabens

District

NLower Cutler Beds faciesinteraction summary. a)Palaeogeographic model fort h e m u l t i p l e s t y l e s o fi n t e r a c t i o n s o b s e r v e dbetween aeolian, fluvial,nearshore and shallow marineenvironments. While themodel shows each of the threeprincipal environment typesactive simultaneously, itshould be noted that this is notnecessarily always the case.b) Schematic regional modelof stratigraphic relationships inthe Lower Cutler Beds and theinter-tonguing of the unit withthe undifferentiated CutlerGroup. Modified after Jordan(2006).

Lower CutlerBeds

Cedar Mesa SandstoneNE SW

Cutler GroupUndivided

Summary depositional model

Regional Stratigraphy

aeolian facies assoc.

fluvial facies assoc.

shallow marinefacies association

Little SpringCanyon

Lower IndianCreek

Deeply incised channels with marine infill

Fluvial channel sandstone with abundant waterescape structures

Gradational transition between calcarenite gritstoneand micritic limestone

Abundant shell debris: lags of crinoid and bivalvefragments

Planar-cross bedded fluvial units with erosive bases

Non-marine bioturbation

Marine units with lags of extraformational clasts

Fluvial-to-aeolian transition marked by unit of wind-rippled sandsheet strata

Very thin but extensive fine-grained fluvial unit

Nodular limestone

Erosively-based channel with calcarenite gritstone infill. Note lateral thinning.

Erosively-based channel (12 m deep) with calcarenite gritstone infill. Channel lag with marine fossil debris. Limestone bedding surface with .Scolicia

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A

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UNCOMPAHGREUPLIFT

CANYONLANDSCAPITOL REEFRICHFIELD

MOAB

Circle Cliffs Trough Emery Arch

Cutler Foredeep

UndividedCutler Gp

LowerCutler Beds

Pre-Cambrian Rocks

Pennsylvanian &Mississippian Rocks

Triassic RocksOrgan Rock Fm

Cedar Mesa Sst

WhiteRim SstToroweap Fm

Kaibab Fm

WE

120 m

0

0 10 20 30 40 km

Cross-bedded sst: aeolian dune Gypsum/evap: sabkha/restricted marine

Carbonate: marine/restricted marine

Sst/mst: sabkha/fluvial

Mst/evap: restricted marine/sabkha

Arkosic sst/cong: fluvial

Arkosic sst/ms: fluvial

Sst/mst: mixed aeolian/marine/sabkha

Stratigraphic panel of Permian units on the ColoradoPlateau. Not all the unit boundaries can be correlatedwith confidence over the distances shown, rather thediagram reflects a generalised stratigraphy. Numbers1, 3 and 4 refer to the regionally extensive sequencesof Blakey (1996), from which the figure is taken.

Four Corners

Utah

Arizona

Nerv

ada

2000 ft

1000 ft300 m

0 0

0

0 100 km

100 miles

Cedar Mesa Sst

Halgaito FmLowerCutlerBeds

Organ Rock Fm

MonumentValley

Monument Valley

Canyonlands Canyonlands

UndividedCutler Gp

Organ Rock Fm

Cedar Mesa Sst

PakoonLst

Pakoon Lst

Hermit FmEsplanade Sst

Esplanade SstSupai FmSedona

Holbrook

Defia

nce

Pla

teau

Magollon

Rim

LowerCutler Beds

Elephant Canyon Fm

See insert in upperleft-hand corner.

Pavant Range

Virgin River

GrandWashCliffs

Grand Canyon

San Rafael Swell

UncompahgreUplift

Paradox

Basin

Grand

Canyon

Zuni - Defiance

Arch

Sedona

Arch

CircleCliffs

Insert

Sandstone, mostly cross-strata: aeolian

Sandstone, variable, tan: marine/sabkha/aeolian

Sandstone/mudstone, red: fluvial/sabkha/marine

Evaporite: sabkha/restricted marine

Carbonate: marine/restricted marine

Arkosic conglomerate, sandstone, mudstone: fluvial

Pre-Cambrian rocksvertical exaggeration 150x

Fence diagram showing thedistribution of major units withinPermian sequence 1 (Blakey(1996), as identified withinsouthern Utah & northernArizona (after Blakey, 1996).Note that the Lower Cutler Bedsare time equivalent to thePakoon Limestone ofArizona.

Uncompahgre Uplift

Arkosic sst and cong.

Mixed sst, mst, lst & cong.

Sst, mst & local lst.

Sst with large cross-beds

Evaporites

Limestone & dolomite

0

0 100 km

100 miles

0

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100 miles

EpicontinentalSea

Lower CutlerBeds

Pakoon Lst

EsplanadeSst

CedarMesaSst

HalgaitoFm

Coast

al s

abkh

a/tid

al f

lats

Arid coastallowlands

Dune field/erg

Alluvialfans

Alluvial Plain

Cutle

rG

p

Cutle

rG

p

Esp

lana

de-C

edar

Mes

aer

g

InlandSabkha

PakoonLst Cedar

MesaSst

SupaiFm

Esplanade Sst

Upper part of intervalremoved by pre-White

Rim Erosion

Edge

ofsi

gnifi

cant

aeolia

ndeposi

ts

QueantoweapSst

Approximate facies limits (left) and inferred palaeogeography(right) for Lower Cutler Beds times. Modified after Blakey(1996). The position of the study localities are indicated.

Approximate facies limits (left) and inferred palaeogeography(right) for Cedar Mesa times. Modified after Blakey (1996).The position of the study localities are indicated.

Facies

Facies

Palaeogeography

Palaeogeography

Limit of Paradoxsalt in subsurface

Limit of Paradoxsalt in subsurface

Studylocalities

Studylocalities

The Lower Cutler beds exposed in the Paradox basin of southeastern Utah represent the preservedremnant of a large, shallow epicontinental sea that occupied a position across much of what is nowsouth-central Utah and north-centralArizona. The incised valley systems replete with nearshore andnon-marine facies, which represent the focus of this study, record the coastline of this sea insoutheast Utah. To the south and west of the Canyonlands region, strata composed of

the Lower Cutler Beds, are knownby a variety of names including the Elephant Canyon Formation and the Pakoon Limestone.

shallowmarine limestones and calcarenites, which are time-equivalent to

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8

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5

Fluvial architectural elements, characterised by cross-bedded and planar-laminatedsandstones and sandy-siltstones, are arranged into multi-storey channel complexesthat commonly exhibit relief on both their basal and upper surfaces.Aeolian architecturalelements, characterised by homogeneous and large-scale cross-bedded sandstonefacies, are arranged into sharp-based units that usually infill topography at the top of theunderlying fluvial units. Shallow marine architectural elements are characterised by bothcalcarenite gritstone facies, arranged into erosively-based co-sets, and micriticlimestone facies, with abundant marine macro-fossils. The coarse-grained calcarenitegritstone facies occur most commonly as complex co-sets of strata, which form the fill ofdeeply-incised channelised elements that cut down into underlying aeolian and fluvialunits. These channels are interpreted to represent incised valleys that were cut by fluvialsystems during periods of relative sea-level lowstand and which were later infilled byshallow marine strata during subsequent transgression. A variety of onlap relationshipsare recognized between strata of marine and non-marine origin at the channel margins.At least five separate marine transgressions are known to have occurred during LowerCutler Beds times and incised valley systems with marine stratal infills are associatedwith each of these flooding events, though only the uppermost three are recorded here.

Study area

Study area

studyarea

Blakey, R.C. (1996) Permian eolian deposits, sequences and sequence boundaries, Colorado Plateau. In: (Eds M.W. Longman, and S.D. Sonnenfeld), Rocky Mountain Section SEPM(Society for Sedimentary Geology, 405-426.

Jordan O.D. (2006) . Unpublished PhD thesis, University of Keele, UK, 328 pages.

Nuccio, V.F. and Condon, S.M. (1996) . U.S. Geol. Surv. Bull., , 41 pages.

Paleozoic Systems of the Rocky Mountain Region

Sedimentology and stratigraphic evolution of the Pennsylvanian-Permian Lower Cutler Beds, Paradox basin, SE Utah

Burial and Thermal History of the Paradox Basin, Utah and Colorado, and the Petroleum Potential of the Middle Pennsylvanian Paradox Formation 2000-O