Kohistan-Gilgit Baltistan

By Samiullah

Department : Geology

University Of Haripur

1

Geological Field Report Kohistan-Gilgit Baltistan

Submitted To:

Sir Salman Ahmad Khattak

Submitted By/Roll No:

Samiullah/5208

Semester:

6th

Department:

Geology

University Of Haripur

2

Samiullah

3

Dedication:

“This is presented as a work of Fiction and Dedicated to our

Beloved and Respectable Parents and Teachers”

4

Acknowledgement:

All acclamation and appreciation are for almighty “Allah” The Magnificent, The Merciful and

His Holy prophet Muhammad (P B U H) who is forever a torch of guidance and knowledge for

humanity. All Praise to All Mighty Allah Who gave us knowledge, education and learning to

work to the best of our abilities, courage and patience to obligation. This Field work could not

have been possible without the generous support and guidance of our teachers, We are grateful to

our respectable teachers Sir Salman Ahmad Khattak And Sir Azeem Shah Lecturers

Department of Geology, University of Haripur for their unforgettable Sympathetic behavior,

helping attitude, hard work and guidance throughout the entire field. We have learned so much

from them and without their efforts; this amazing field would not have been possible.

Last but not the least, any acknowledgement could never adequately express our obligation to

our loving friends for, their motivation, support and for memorable time we spent together.

Thanks are also extended to all our friends especially to Mr.Afaq Ahmad Zaman, Mr. Roman

Khan, Mr.Ahzaz Ahsan, Mr. Ibrahim Khan, Mr. Ahzaz Khan, and Mr.Yousaf for their nice

and helpful company during our entire field.

Samiullah

5

Table of Contents:S.No Contents Page. No1 Dedication2 Acknowledge3 1. Introduction4 1.1 Aim of study5 1.2 Physiography6 2. Literature review7 2.1. Geology of Northern areas of Pakistan8 2.2. Karakorum Plates9 2.3. Northern suture zone10 2.4. Kohistan island arc11 2.5. Besham group12 2.6. Brief description of rocks13 3. Field Observation14 3.1. Day# 1) UOH to Besham15 3.1.1. Stop# 1) Muslimabad16 3.1.2. Stop# 2) Mansehra start17 3.1.3. Stop# 3) Near Ahal village18 3.1.4. Stop# 4)Near Ahal village19 3.1.5. Stop# 5)Near Chattar plane20 3.1.6. Stop# 6)Sorai Pul Batagram21 3.1.7. Stop# 7) Way to Besham22 3.2. Day# 2) Besham to Chilas23 3.2.1. Stop#1) Besham bridge, Besham24 3.2.2. Stop# 2) Munji Near Besham city25 3.2.3. Stop# 3) Lahor nala26 3.2.4. Stop# 5) Chikai Bankal, Kohistan27 3.2.5. Stop# 6) Dubair28 3.2.6. Stop# 7) Jijal29 3.2.7. Stop# 8) Galozebanda30 3.2.8. Stop# 9) Near pattan, Kohistan31 3.2.9. Stop# 9) Pattan, Kohistan32 3.2.10. Stop# 10) Kayal turn33 3.2.11. Stop# 11) Qasoorabad

6

34 3.2.12. Stop# 12) Dasu dam project35 3.3. Day# 3) Chilas to Gilgit36 3.3.1. Stop# 1) Chilas city37 3.3.2. Stop# 2) Near Chilas38 3.3.3. Stop# 4) Babusar Chowk39 3.3.4. Stop# 5) Raikot Near bridge40 3.3.5. Stop# 5) Thilchi41 3.3.6. Stop# 6) Near thilchi42 3.3.7. Stop# 7) Bunji- Jaglot43 3.3.8. Stop# 8) Junction points of rivers and

mountain44 3.4. Day# 4) Gilgit to Hunza45 3.4.1. Stop# 1) Jutal46 3.4.2. Stop# 2) Near Nommal47 3.4.3. Stop# 3) Plate collisional point48 3.4.4. Stop# 4) Chalt village49 3.5. Day# 5) Gilgit to Besham

50 3.6. Day# 6) Besham to UOH

51 3.6.1. Stop# 1) B/W Shangla and Thakot52 Reference

7

1) Introduction:

The field trip provides a geological cross-section in Northern Pakistan

from the margin of the Indian Plate to the Hindu Kush terrine, through the Kohistan Island Arc

and the Karakoram Range. The area includes Muslimabad (Abbottabad) to Gilgit crossing

Kohistan. Geologically it is located in south of northern suture zone, a mega trust separating the

rocks of Karakorum late from Kohistan island arc. The rocks exposed in this area are mainly

basalts andesite sheet dominant volcanic and igneous rocks, and in some places there are

metasedimentary rocks.

This field trip compromises of 6 days start from 2nd-7th May, 2016. We

started our trip from university and first stop is at Muslimabad where we observed angular

unconformity Hazara slates and Thanaki conglomerates. We studied different types of

metamorphic and igneous rocks from Besham to Hunza including the areas of Kohistan and

Gilgit. These rocks are diorites, dunites, gabbro .basalt, gabbro norites, Pyroxinites.

Aim of Study:1.1 The geological Fieldwork and report writing is an essential

requirement for BS degree in Geology .Students of BS semester VI have done field work for

one weeks in areas of Mansehra, Besham, Kohistan ,Gilgit and Hunza, Which was carried out In

the month of May 2nd, 2016. The main purpose of field is:

Identifications of different types of rocks

Regional geology of the area

Geomorphology of an area

Geological mapping

Visit to different Dam Sites.

8

1.2) Physiography:

1.2.1) Relief:

The Mapped Area lies between the Muslimabad (Abbottabad) to Hunza.

The highest elevation from sea level is 1833 feet in Hunza.

The lowest elevation from sea level is 617 near Besham.

1.2.2) Climate:

The Climate of Gilgit varies from region to region; surrounding mountain

ranges creates sharp variations in weather. The eastern part has the moist zone of the western

Himalayas, but going towards Karakoram and Hindu Kush the climate dries considerably. Gilgit

is hot during the day in summer yet cold at night and valleys like Astore, Khaplu, Yasin, Hunza

and Nagar where the temperature is cold even during the summer.

1.2.3) Vegetation covers:

In northern areas of Pakistan mostly area is barren. There is no vegetation on

mountain due to lack of rains.in some areas of Kohistan and Hunza there is some vegetation

cover which conceals the geology of different areas. There are different types of herb and herbs

are found in it.

1.2.4) Weathering:

Weathering is the total effect of all the various sub aerial processes that

cooperate in bringing about the decay and disintegration of the rocks. Weathering of rocks

depends upon following factors,

Mineral composition and structure of the rock

9

Climatic condition

Presence and absence of vegetation

Topography of the area

Weathering is of three types

Mechanical or Physical Weathering

Chemical Weathering

Biological Weathering

10

2) Literature review: 2.1 Geology of Northern Pakistan:

Gilgit-Baltistan covering the most area of Northern Pakistan. The northern

area of Pakistan mainly compromises of three tectonics plates. These plates are Karakorum Plate,

Kohistan Island Arc and Indo-Pakistan Plate. Kohistan Island Arc is sandwiched between

Karakorum plate and Indo-Pakistan Plate by having two main trusts the NSZ or MKT in the

north and Indian suture zone ISZ or main mantle thrust MMT in the south. The region of GB is

mainly composed of rocks of Karakorum plates (i.e. metasedimentary and metaigneous rocks),

northern suture zones (i.e. Ophiolites mélanges) and Kohistan Island Arc (i.e. mafic-ultramafic

complex and Batholith plutons).The crystalline basement of Karakoram consists of low-grade

quartzite and migmatites, which are in turn intruded by a granodiorite.

The quartzite (Chikar quartzite) consists of darkgrey siltstones and

quartzite, largely derived from green schist-facies metamorphism of poorly sorted sub arkoses.

This metaterrigenous unit forms km wide open folds, and is transformed into hard spotted schist

and massive hornfels-like rocks close to the contact with the granodiorite. Granitic dikes intrude

the met sediments.

The migmatites occur to the SE of Chikar, and up the right bank of the

Darkot Pass glacier, where the met sediments become increasingly intruded by granitic dikes. In

a few km, the injected met sediments seem to gradually give way to migmatites, and into

anatectic granite engulfing masses of nebulitic gneisses and agmatitic amphibolite.

The granodiorites occur in apophyges 4-5 km wide (Kishmanja,

Ishkarwaz) and in thrusted sheets and slices, 4 to 10 km long (in front of Kan Khun). The Granite

bears biotite and frequent amphibole, almost totally altered.

2.2) Karakorum Plates:

Karakorum plates represent the northern most part of Pakistan and it is

located on the northern side of NSZ or MKT. The rock body exposed here are highly deformed

11

sedimentary, metasedimentary, and igneous assemblages and they are ranges in age of Jurassic to

late Cretaceous and formed as a result of collision between KIA with Eurasian plate along NSZ

or MKT. The Karakorum plate is divides into;

I. The Northern Sedimentary Belt

II. The Karakorum Axial Batholith

III. The Southern Metamorphic Belt

2.2.1) The Northern Sedimentary Belt;

The northern sedimentary belt is northern most unit of Karakorum block

and is mainly consisting of up to 7km thick belt which is transgressive on a pre-Ordovician

crystalline basement rocks. The sedimentary belt is further divided into thrust sheet in Chitral

and Hunza Valley along the western and eastern margin of Karakorum block. The rock body

present in this block ranges in age from Permian to Paleozoic and most of the succession with

the eastern Karakorum along Hunza valley are of Permian age. The Hunza include calc-alkaline

granodiorite which has both biotite and hornblende minerals.

2.2.2) The Karakorum Axial Batholith;

12

It is a large body of igneous rocks intrudes in different times and the

earliest magmatic episode is recorded earlier than 100 Ma and can be correlated with the initial

stages of intra-oceanic subduction. The extension of this batholith is up to Ladakh in the east and

across into Afghanistan in west. The northern sedimentary belt in the northern of Karakorum

plates is separated from the marginal mass present in the southern part of the Karakorum plate by

this axial batholith in the Hindukush and Karakorum ranges. The dominant rocks phases of this

batholith are granodiorites, granites and pegmatite’s which are readily intruded by the sills and

dykes mostly basic in nature.

At least three major tectonics episodes of magmatic intrusion were

identified in the magma axial batholith. The earliest episode was in the mid –Cretaceous and

mainly consisting of sub alkaline and calc-alkaline intrusion. The second phase of intrusion

consists of sub-alkaline granites of Eocene age having mainly biotite, amphiboles and

andalusites. The last episode occurred in Miocene and is represented by leucogrsnites sheets and

intrusion of batholithic dimensions.

A linear batholithic body, about 20 km wide and 150 km long,

occupies higher peaks of the Eastern Karakoram and Pangong Mountain in Ladakh. This

batholith extends into the western

Karakoram across the Baura range. Hispar, Biafo to the west of

Baltoro and is known as Karakoram axial batholith. In general, the Karakoram batholith is

porphyritic in texture and pink in color but in western Karakoram homogeneous and fine grained

with occasional coarse grained varieties are also reported. The belt occurs as an elongated

arcuate composite body comprising different sub-alkaline and calc-alkaline unit

13

Simplify Ed structural map of North-West Pakistan. (Modify end from Gaetano 1997)

2.2.3) The Southern Metamorphic Belt

The southern metamorphic belt of the Karakorum plates is developed

as a hanging wall along the NSZ or MKT. the difference group is included in this belt are

variously named as we move from the western to the eastern margins (i.e. chitral slate in Hindu

Kush, Darkot group in the Yasin valley, Baltit group and Damurdu Formation in the Hunza

valley and Shigar group in the Baltistan group). The low grade metamorphic rock in this belt are

biotite schist ,chlorites schist ,quartz schist ,while the high grade metamorphism is demarcated

by kyanites and illuminates schist’s.

2.3) Northern Suture Zones or Main Karakorum Thrust (MKT);

14

Main Karakorum Thrust is a fault contact which separates the rocks of Eurasian plates from that of KIA. This suture zones is formed as a result of collision of KIA with Eurasian plates. NSZ is a compromise of ophiolites mélange containing rocks like’s serpentines, volcanic and marine.

Sediments in a slate. The different types of sedimentary volcanic

present on the northern sides of KIA are separated from the slates and quartzite of the Eurasian

plates by this mélange. The rock body are present along this thick mélange are limestone’s,

quartz, volcanic greenstones and altered rocks like serpentine in a slates matrix.

2.4) Kohistan Island Arc: Kohistan island arc is formed as a result of intra oceanic

subduction of neo Tethys beneath Eurasian plate in late Jurassic to Early Cretaceous times and

covering an area of about 3600 km2. KIA is separated from the Indian plates by MMT or ISZ in

the south while its northern boundary is marked by MKT or NSZ which separate it from the

Eurasian volcanic rocks .KIA consist of associated volcanic rocks. KIA consists of the following

geological bodies of rocks as we move from north to south.

1. Yasin Group Sediments

2. Chalt Volcanic Group

3. Kohistan batholith

4. Chilas complex

5. Jijal complex

2.4.1) Yasin group Sediment:

Yasin sedimentary group represent the northern part of KIA and

they are youngest Tethyan remains comprised of mainly sedimentary and volcanic clastic rocks.

The volcanic rocks are metamorphosed to green schist facies due to volcanic collision of two

plates. This group show variable lithology along different part of the NSZ.in the Eastern part

15

along Hunza Valley ,this group contain volcano clastic , terrigenious slate , silty quartzite and

pebble conglomerates while limestone unit is absent .

2.4.2) Chalt volcanic group:

The rocks of the chalt volcanic group are exposed in the south of

NSZ. Chalt volcanic group is composed of basalt rhydacites and andesite and are generally

metamorphosed to green schist facies. The volcanic rock present in the zone are highly deformed

and shows metamorphic grade from green schist in the West to amphibolite facies in the south.

The volcanic or Meta volcanic present in this group are divided on the basis of their geochemical

contents,

One group is having MgO contents between 15 and 6% while

Second group is having less than 6 %

2.4.3) Kohistan Batholith:

The presence of major belt of granitic rocks in the northern part

of KIA were first described but Tahir kheli and Jan .These were later on named as Kohistan

batholith by Peterson and Windley . The major components of KIA are represented by Kohistan

batholith. The area covered by this series along E-W direction is 300 Km and along N-S

direction is 60Km.Different rock bodies present in tis batholith are; granodiorite, diorite,

hornblende, hornblende, gabbro and lecogranites. Kohistan batholith is formed as a result of

three stages of magmatic intrusion .the geochemistry of first stage is recognized by two Magma

types. The first type of magma is represented by medium to high potassium diorite, the second is

low potassium trondhjemites. The second type of the rock present in the first stage has unique

feature having a lack of enrichment in LREE relative to HREE.stage three pluton present within

the Kohistan island arc forms the minor part of the batholith. The age assigned to this group is 30

Ma.

16

2.4.4) Chilas Complex:

Chilas complex is representing the southern part of KIA and

consisting mainly of pyroxene-diorites and gabbro norites with the minor amount of gabbro,

anthracite, troctolites, peridotites and the mafic dyke .in the southern part of KIA .this group is

extending 300 Km along the E-W and 40 Km along the N-S, the rock group present in this

complex are in the age from late Jurassic to Cretaceous .IN southern part, Chilas complex has a

Tectonic contact with Kamila amphibolite.

2.4.5) Kamila Amphibolite:

It lies in the south of Chilas Complex and mainly consist of two

varieties of Amphibolite .one variety is medium to coarse grained Amphibolite while, the other is

fined grained banded or homogeneous amphibolite. Width of the Kamila Amphibolite is 10 to 40

Km and is present all along the southern Kohistan batholith. Structural data and there age suggest

that the deformation and metamorphism occurred before the collision of KIA with Indian Plate.

The rock shows very close resemblance with the chilas complex Gabbronorite and suggesting the

same origin.

2.4.6) Jijal Complex:

Jijal complex having basal cumulates, layered gabbro and ultra-

mafic rock lies in the southern part of KIA consisting of about 150 Km2 and represent the deepest

part of the arc. Two distinct units in the complex are;

Ultramafic rocks ,consisting of dunites, harzburgites ,websterities and clino pyroxinites

Garnet granulite.

The granulite present in this complex are of two types, on having plagioclase and other is

free of plagioclase. The plagioclase free variety I ultrabasic to basic and other variety

having plagioclase is basic to intermediate in nature. The lithology exposed in this group

is granulite and ultramafic rocks.

17

2.5) Besham Group:

The Besham Group comprises a heterogeneous mixture of biotitic

gneisses and schists (most of uncertain paragenesis), granitic gneisses, metapsammites,

amphibolites, blue-quartz pegmatites and other pegmatites, weakly deformed hornblende-

granodiorite, mylonites, phyllonites and undeformed microgranites. The gneisses are medium to

coarse grained. The metapsarnmites are often fine grained with a granoblastic texture, e.g. the

top of each of the thrust slices west of Besham (where biotite is an essential phase), but are

coarse grained and more arkosic in other areas. Lead-zinc sulphide deposits occur within the

metasediments of the Besham Group in several areas, the largest being at Lahor and Pazang on

the west and east banks of the Indus, respectively. The deposits occur in folded stratigraphically

controlled lodes which have been extensively remobilised during Himalayan shearing and later

faulting so that they are now also partly structurally controlled. The gneissic textures and fabrics

with a quartz, feldspar, muscovite, biotite, and garnet and hornblendic-amphibole mineralogy are

the products of the pre-Himalayan high-grade deformation and metamorphism with its associated

granite and pegmatite intrusion.

2.6) Brief Description of Rock:2.6.1) Diorite: 1) Diorite  is an intrusive igneous rock composed principally of the silicate minerals plagioclase feldspar ,biotite, hornblende, pyroxene.

2) The chemical composition of diorite is intermediate, between that of mafic gabbro and felsic granite.

3)  Diorite is usually grey to dark-grey in color, but it can also be black or bluish-grey, and frequently has a greenish cast.

4) Diorite may contain small amounts of quartz, microcline, and olivine. Zircon, apatite, titanite, magnetite, ilmenite, and sulfides occur as accessory minerals. Minor amounts of muscovite may also be present.

18

2.6.2) Dunite: 1)Dunite (also known as olivinite) not to be is an igneous, plutonic rock, of ultramafic composition, with coarse-grained or phaneritic texture.

2) The mineral assemblage is greater than 90% olivine, with minor amounts of other minerals such as pyroxene, chromite, magnetite, and pyrope.

3) Dunite typically undergoes retrograde metamorphism in near-surface environments and is altered to serpentinite and soapstone.

2.6.3) Gabbro: 1) Gabbro mafic intrusive igneous rocks chemically equivalent to basalt.

2) Gabbro is dense, greenish or dark-colored and contains pyroxene, plagioclase, and minor amounts of amphibole and olivine.

3) Gabbro is generally coarse grained, with crystals in the size range of 1 mm or greater. Finer grained equivalents of gabbro are called diabase (also known as dolerite).

2.6.4) Granodiorite: 1) Granodiorite is a medium- to coarse-grained intermediate to acid igneous rock with essential quartz (>20%), plagioclase (oligoclase) and alkali feldspar, with minor mafic minerals, typically hornblende and biotite.

2) The fine-grained equivalent of granodiorite is a dacite.

3) Granodiorites are most commonly related to island arc and orogenic magmatism and are usually calc-alkaline magmas.

4) They are usually associated with granite and tonalite intrusions

2.6.5) Amphibolite: 1) Amphibolite is a coarse-grained metamorphic rock that is composed mainly of green, brown, or black amphibole minerals and plagioclase feldspar.

2) The amphiboles are usually members of the hornblende group.

2.6.6) Slate:

19

1) Slate is a fine-grained, foliated metamorphic rock that is created by the alteration of shale or mudstone by low-grade regional metamorphism.

2) Slate can also contain abundant quartz and small amounts of feldspar, calcite, pyrite, hematite and other minerals.

3) Most slates are gray in color and range in a continuum of shades from light to dark gray. Slate also occurs in shades of green, red, black, purple and brown.

2.6.7) Schist: 1) Schist is a metamorphic rock consisting of mineral grains that are more or less aligned in layers. Because of this structure, schist tends to cleave into flakes or slabs.

2) The parent rock of a schist may be igneous (e.g., basalt, granite, syenite) or sedimentary (e.g., sandstone, mudstone, impure limestone).

3) Minerals include micas, chlorite, talc, hornblende, graphite, and others.

4) Schist forms at a higher temperature and has larger grains than phyllite.

2.6.8) Phyllite: 1) Phyllite is a type of foliated metamorphic rock created from slate that is further metamorphosed so that very fine grained white mica achieves a preferred orientation.

2) The protolith (or parent rock) for phyllite is shale or pelite, or slate, which in turn came from a shale protolith.

3) Phyllite has good fissility (a tendency to split into sheets). Phyllites are usually black to gray or light greenish gray in color.

20

3) Field Observation:

3.1) Day # 1 UOH to Besham3.1.1) Stop# 1: Muslimabad (Kotaqabar section) Time: 10:36am

34°06'08.3"N

73°10'14.3"E

Observations:

At this stop we observed Hazara Slates, Thanaki Conglomerates and Angular Unconfirmity.

Description:

Hazara formation has two sections

1) Hazara slates which is of Precambrian age and contain low metamorphosed slates.2) Abbottabad formation which is of Cambrian age and contain dolomite and limestone.

At this stop we observed “Angular unconformity” in which the above strata consist of Abbottabad formaton and below strata consist of Hazara slates.Between them is conglomerates which is also known as “Thanaki conglomerates”

21

Fig#1: Reprsenting angular unconfirmity and thanaki conglomerates.

22

3.1.2) Stop# 2: Mansehra StartTime: 12:25am

Rocks Observed:

Slates

Description:

At this stop we observed slates which are well known as Hazara Slates. This slate is of Precambrian age. Color of the slate was Dark Grey color. Texture of this slate was fabric texture. Foliation present in the slates we can divid it into the slabs. Foliation is basically Fabric forming planner structures.

Fig# 1) Hazara slates at start of Mansehra

3.1.3 Stop# 3) Near Ahal Vllage Time: 3:13 am

23

N 34°33'41.3"

E 073°09'22.0"

Elevation: 1488m

Rocks Observed:

Granite (Granodorite)

Description:

The rocks observed at this stop were granite, which is usually in the form of crushed material .There is also some amount of mafic minerals in it. This crushing is due to foliation. This foliation is due to the alignment of minerals which is disturbed by either shear zone or faulted zone. Mostly the rocks are hard enough but crushing is due to this fault. As we know that granite is hard rock and we saw crushing in it. It means that forces are very high magnitude. This is part of mansehra batholith. Scistocity and gniesstocity is also present due to shearing. Age of these rocks is 516my (Cambrian).Swat granite and Ahal granite form at same time. Hazara formaton is basically related to Panjal Fault. Granodiorite is very similar to granite. It has less of the potassium variety of feldspar, more of the sodium feldspar.

Minerals present in the rocks:

Feldspur, Silica, Biotite and hornblende.

Fig#1) Granitic rock Near Ahal Village.

3.1.4 Stop# 4) Near Ahal Village but at some distance from Stop# 3\

24

Time: 3:20pm

N 34°37'34.9"

E 73°05'50.2"

Elevation: 1488m

Rocks Observed:

Granite

Description:

The rocks we observed at this stop was granite which was in the form of crushed. This crushing is due to major shearing zone. It is part of main Oghi Trust. Oghi shear zone meet with Butal fault (In Kaghan Valley) and most people consider it MCT (Main Continental Thrust).But actually these fault are much older than MCT.In some zone we found folation in the rocks and in some zone we donot found foliation.

Minerals Observed:

Quartz, Biotie and Feldspur

Fig# 1) Granitic rock near ahal village

25

3.1.5 Stop# 5) near chattar PlaneTime: 4:15pm

Rock Observed:

Gneiss (ortho)

Description:

The rock observed at this stop is basically a granitic igneous rock which is metamorphosed at high grade of metamorphism and is converted into Gneiss. So this rock is called orthogenesis. This rock had a patch of a light and dark band of mineral which show it is a gneiss rock. This rock has a band of minerals. As increase in grade of metamorphism there is foliation and minerals are fully aligned. The light and dark minerals are in separate patches. On light band there is dark band present of top and bottom. The minerals like mica, Muscovites and biotite are present in it. The rock has a coarser texture. In this the crystallinity is high. There was also some schistocity along the right side of gneiss. Vein is also present.

Minerals Observed:

The minerals observed in these rocks are Muscovites, Biotite and Micas.

Fig# 1) Orthogniess in chattar plane.

26

Fig#2) Vein present in orthogniess in Chattar plane.

3.1.6 Stop# 6) Sorai Pul BatagramTime: 5:57pm

N 34°41'4.6"

E 72°59'24.5"

Elevation: 1026m

Rocks Observed:

Gneiss (Augend)

Description:

The rocks observed at this stop was gneiss have Augen structures. These are part of Mansehra granite that metamorphosed means protolith of these gneiss was granite or granodiorite.Mega crystals of mansehra granite, when pressure exert on these crystals they

27

becomes elongated and develop Augen structures. Gniesstocity is more in these granites and Tanawal quartzite is intrudes by this granite.

Fig# 1) Augen structure in the rocks in Sorai pull, Batagram.

Fig#2) Gniess rocks in Sorai Pull, Batagram.

28

3.1.7 Stop# 7) Way to be shamTime: 6:40pm

N 34°44'34.4"

E 72°57'9.3"

Elevation: 757m

Rocks Observed:

1) Garnet-mica schist2) Igneous rocks3) Gniess(Para)4) Quartzite5) Graphite schist

Description:

At this stop we observed Quartzite then we observed igneous bodies And After that we observed sedimentary rocks which were metamorphosed and then we observed gneiss Of which protolith is Sedmentary rocks then we observed Quartzite which was repeated and at same place we observed Graphite schist. Overall this section is part of Ganduf formation which mostly consists of sedimentary rocks but here metamorphosed And In some Places we observed Granitic rocks which is a part of Kotla formation. Kotla formation is in the form of small sills.

29

Fig# 2) Graphite Schist of Ganduf formation.

3.2) Day# 2 From Besham to Chilas

3.2.1 Stop# 1) Besham Bridge, BeshamTime: 8:58am

N 34°55'41.1"

E 072°52'36"

Elevation: 607m

Rocks Observed:

Granodiorite, Schist, Quartzite, Gniess.

Description:

30

At this stop we observed Schist, Granodiorite, Quartzite, Gneiss, and Amphibolite. This section is part of Besham Complex. The granodiorite observed here is also called Shange Granodiorite whose age is 1836my.Amphibolite is also observed. Gniesstocity is present in the rocks. Schistocity is also present but not too much. Mafic intrusion was also present below the iron bridge.

Minerals Observed:

Quartz, Amphibole, Feldspur, botite

Fig#1) Mafic

Intrusion under Besham iron Bridge in (?) Rocks In Besham.

31

Fig# 2) Rocks Of besham Complex, Besham Bridge, Besham.

3.2.2 Stop# 2) Mungi Near Besham CityTime: 9:59 am

N 34°56'39.1"

E 72°52'42.3"

Elevation: 561m

Rocks Observed:

Metasedimentary Rocks

Description:

The rocks observed at this stop was metasedimentary rocks that contain Feldspur, Quartz and Biotite.Quartz vein was also present in the rocks. Some researchers named it paragniss and some researchers named it Kishar formaton.This section`s rocks is also part of Besham complex. Age of the rocks is Precambrian.

Mineral Observed:

Biotite, feldspar and Quartz

Fig# 1) Metasedimentary rocks, Mungi near Besham city.

32

3.2.3 Stop# 3) Lahor Nali Time: 10:30 am

N 34°57'34.3"

E 72°52'47.3"

Elevation: 748m

Rocks Observed:

Metasedimentary rocks

Description:

At this stop we observed Metasedimentary rocks which consist of Biotite and Mica. Color of the rock was greenish. Grainsize was medium to fine.

Minerals Observed:

Biotite, Mica

Fig# 1) Metasedimentary rocks, Lahor Nali

33

3.2.4 Stop# 4) Chikai Bankal, KohistanTime: 10:55 am

N 34°59'32.0"

E 72°54'22.6"

Elevation: 755m

Rocks Observed:

Granite

Description:

At this stop we observed Granite of light color which is also called Lecugranites. This granite is also named as lahor granite. Age of this granite is Precambrian.

Fig# 1) Granite at Chikai Bankal, Kohistan.

34

3.2.5 Stop# 5) Dubair Time: 11:54 am

Rocks Observed:

Granodiorite

Description:

This met granodiorite (biotite – hornblende) belongs to the Precambrian “Besham Group”. This Meta diorite deformed heterogeneously, and displays unfoliated facies with angular xenoliths. The foliation intensity varies from almost none to pronounce into mylonitic bands.

Granites are coarse-grained intrusive igneous rocks made of two different kinds of feldspar (potassium- and sodium-rich), together with quartz and a small proportion of dark minerals. In this view of granite, the feldspars have a dusty appearance, and the quartz is clear. The only "dark" mineral is a small amount of yellow tourmaline.

Granodiorite is very similar to granite. It has less of the potassium variety of feldspar, more of the sodium feldspar (plagioclase). The dark minerals in this rock include green hornblende and brown mica (biotite). This Granodiorite is equal to Shange granodiorite.

Minerals Observed:

Botite, hornblende and plagioclase.

Fig# 1) Granodiorite in Dubair (On Way to Kohistan)

35

Fig# 1) Dunite rock, jijal

3.2.6 Stop# 6) Jijal Time: 11:50 am

N 35°02'19.0"

E 72°56'13.0"

Elevation: 938m

Rocks Observed:

Dunite (Peridodite)

Description:

At this stop we observed dunite which mostly consists of Olivne. Olivine has green color that shows some transparency .Dunite contain more than 90 percent of the olivine. Peridotite was also observed in this stop which consist of dark color minerals like pyroxene, amphibole. This section is part of the kohistan island arc. MMT (Main mantle thrust) lies at the back side of this section. Mostly MMT is marked by Blueschist but In Kohistan Island arc we donot found it.

Minerals Observed:

Olivine

36

3.2.7 Stop# 7) Galozbanda, KohistanTime: 12:22 pm

N 35°04'12.8"

E 72°57`19.8``

Elevation: 858m

Rocks Observed:

Peridodite

Description:

At this stop we observed Peridodite. Serpentinization was also observed in the rocks. Minerals present in the rocks are hornblende, mica and olivine. The alteration of these minerals is very easy. This section is part of jijal complex.

Mineral Observed:

Hornblende, Micas and Olivine.

Fig# 1) Hornblende in peridodite rock of Galozebanda, Kohistan.

37

3.2.8 Stop# 8) Near Pattan, KohistanTime: 12:45 pm

N 35°04'37.8"

E 72°57'49.5"

Elevation: 914m

Rocks Observed:

Garnet granulite

Description:

At this stop we observed garnet granulite; texture of the rock is granular. Age of the rocks is creataceous.This section is part of Jijal complex. A granulite is a fine- to medium-grained metamorphic rock with a granular texture of polygonal crystals (granoblastic texture). Granulites typically contain amphibole, quartz, feldspar and pyroxene with very little or no mica. Granulites frequently contain garnet, kyanite, sillimanite and/or sapphirine. Granulites form by regional metamorphism of a wide range of protoliths including argillaceous and arenaceous sediments, mixed siliciclastic and carbonate sediments and igneous rocks.

Minerals Observed:

Garnet, Pyroxene, Plagioclase, Quartz

38

Fig# 1) Garnet Granulite.

3.2.9 Stop# 9) Pattan, KohistanTime: 1:25 pm

N 35°07'04.6"

E 72°58'6.1"

Elevation: 837m

Rocks Observed:

Gabbro

Description:

At this stop we observe Gabbro. But we also observe gniesstocity which may be mafic gniess that may be formed by forceful injection of the magma that elongate the minerals. At this section magmatization may be occurred. The grain size of the rock is fine. The rocks observed at this stop are a part of Kohistan Island Arc.

Fig# 1) Contact b/w gabbro and mafic gneiss, Pattan Kohistan.

39

Fig# 2) Mafic gneiss and Augen structure in Pattan, Kohistan.

3.2.10 Stop# 10) Kayal TurnTime: 1:45 pm

N 35°09' 9.2"

E 72°58'6.1"

Elevation: 840m

Rocks Observed:

Gabbros and Amphibolites

40

Description:

At this stop we observed mafic rocks gabbro and amphibolites. Amphibolite is a metamorphic rock whereas gabbro is an igneous rock. Grain size is fine. Intrusion produces shearing and form bending. The rocks of this section are include in the Kamila amphibolites.Foliation was present in the rocks. Color of the rock was dark.

Minerals Observed:

Amphibole

Fig# 1) Amphibole mineral in the rocks , Kayal Turn.

3.2.11 Stop# 11) Qasoorabad Time: 2:30 pm

41

N 35°09' 9.2"

E 73°05' 23.1"

Elevation: 867m

Rocks Observed:

Amphibolite

Description:

The rocks observed at this stop were amphibolite. There was not too much foliation in the rocks but at some places foliation was present. In some places serpentinizaton was observed. Rock color was darker.

Minerals Observed:

Amphibole, Olivine.

Fig# 1) Amphibolite minerals in the rocks in Qasoorabad.

3.2.12 Stop# 12) Dasu Dam Project Time: 4:00 pm

42

N 35° 19' 2.1"

E 73° 11' 43.1"

Elevation: 779m

Rocks Observed:

Gabbro, Gabbronorites

Description:

The rocks observed at this stop were gabbros mostly.Gabbronorites was also marks in this section. The rocks of this section were part of Chilas complex. This section was part of Dasu dam projects. Axis of dam was also observed in this section. Tunneling was present that were drilled for engineering properties of rocks.

Minerals Observed:

Augite, Hypersthene.

Fig# 1) Dasu Dam Project. Axis of dam.

43

44

Fig# 2) Silent Features of Dasu hydropower Project, Dasu

3.3 Day# 3) Chilas to Gilgit3.3.1 Stop #3.1) Chilas City Time: 10:12 am

N= 35̊ 25̍ 42.7̎

E=74̊ 6̍ 31.2 ̎

Elevation =1064m

3.3.1.1) Study about Geomorphology:

In this stop we observed different geomorphological

features. This area has rocks which are of Paleocene age. These areas are covered with ice or

45

glacier. This area was extended in large area. Sediment in this area is mostly moraines, debris flow and some channels which were formed by melting of ice. Due to melting of these glaciers there is well sorted sediment. There were some sand patches which were formed due to wind after long time. At below surface there is gabbroic plutonic rock of chilas Complex and at top there were glacier sediment, so there is unconformity called non-conformity. The age assigned to these is 105-110MY cretaceous time periods. In this area there are small lenses were formed, these lenses were due to different small channels, which were developed at different time. These types of sediment are basically called Jalipur Sediment.

3.3.1.2) Study about Geological Cross Sections;

We also did geological cross sections of that area. We draw sketches of lithology, contact, unconformity, moraines, river, mountains, channels and different alluvial fans.

46

Fig# 1) Geomorphology of Area near Chilas City, Chilas

3.3.2 Stop# 2) Near Chilas City Time: 10:28 am

N 35° 25' 05.7"

E 74° 07' 32.2"

Elevation: 1034m

Rocks Observed:

Diorites

Description:

47

At this stop we observed Diorites which contain whitish color feldspar. Transparent quartz, blackish Amphibole, greenish Pyroxene. Texture of the rock was phonetic. Diorite s mostly found in Kohistan Batholiths. Garnet, pegmatites and applied veins are also present in some places. Mafic intrusion was also present. This mafic intrusion occurs in different stages 105my – 130my

1) Diorite intrusion along mafic intrusion in 105my.2) Granitic intrusion in 85- 50my3) Pegmatite or granitic intrusion in 40- 45my.

Minerals Observed:

Feldspur, Quartz, Hornblende and Pyroxene.

Fig# 1) Diorites near Chilas city

3.3.3 Stop# 3) Babu SAR ChowkTime: 11:15 am

48

N=35̊ 24̍ 24̎

E=74̊ 8̎ 48.6̎

Elevation =1051m

Rocks Observed:

Different rocks are observed in this stop.

Gabbro or gabbroic rock, Norites or gabbro norites, Dunites, Peridoditc rocks.

Descriptions:

The first stop that was observed in this stop is gabbro .The gabbro is mafic rock and has some amount of olivine and plagioclase. The greenish color represented that that rock was gabbro. In gabbro the amount of blackish minerals is high. The amount of plagioclase is also high in it. These rocks are not totally gabbro may be they were tonality rock. In gabbro the pyroxene amount is high. Gabbro is a coarse-grained and usually dark-colored igneous rock. Gabbro is an intrusive rock. It means that it formed as magma cooled slowly in the crust.

The second rock that was observed were Dunites rocks. This rock has a vitreous lusture. In this rock pyroxene is much less. If Dunites has 90% of pyroxene that this may be peridotites.

There are also some vein of pegmatite’s which are intruded in it. Peridotite is a generic name used for coarse-grained, dark-colored, ultramafic igneous rocks. Peridotites usually contain olivine as their primary mineral, frequently with other mafic minerals such as pyroxenes and amphiboles. Their silica content is low compared to other igneous rocks, and they contain very little quartz and feldspar. There was also a peridotitic rock which has pyroxene minerals. In this rock there is black, shining, vitreous, elongated minerals called hornblendites also present. The rock which has hornblende is called hornblendities. These all rocks a parts of Kohistan batholith.

Unites and peridotites are light greenish grey to dark grey with greasy appearance. These rocks are partially serpentinized. This phenomenon is more prominent in the rocks along southern contact. Shearing of the rocks has taken place and serpentinization is intense along joints, weak and sheared zones. Serpentinites are light grey and brown to dark grey in colour. Dark grey and thin veins of serpentinite are also seen in these rocks. Chrornitite has been found with these rocks on the basal side as massive lenses and layered bodies. Magnetite dissemination is common in peridotites and dunites and is upto a maximum of 20% in the rocks so far observed. These rocks are magnetic in character.

49

Minerals Observed:

There are different types of minerals observed in these rocks which are;

Pyroxene, Olivine, Plagioclase, Hornblendes, Quartz, Peridotites.

Fig# 1) Biotite in Quartz vein, Babusar Chowk, Chilas

Fig# 2) Pyroxnoid rock , Babu sar chowk.

50

Fig# 1) Intrusion of different Rocks at Babu sar chowk

Fig# 2) Amphibole mineral in Quartz vein.

51

3.3.4 Stop# 4) Raikot Near BridgeTime: 3:45pm

N 35° 29' 40.7"

E 74° 36' 9.5"

Elevation: 1231m

Rocks Observed:

Diorites

Description:

At his stop we observed Diorites of medium grain size. These rocks are also part of Kohistan batholiths. Pagmatite veins was also present the rocks. On the way many springs were observed that represent Raikot Fault. Raikot fault is a strike slip fault. Many Pleistocene deposits were observed. On the right side of the road Himalayas were present and MMT pass through this zone.

Fig#1)Diorites and pegmatite’s vein in diorites.

3.3.5 Stop #3.5 Thilichi Time: 4:45 pm

52

N 35° 35' 37.7"

E 74° 37' 24.5"

Elevation: 1294m

Rocks Observed:

Metasedimentary rocks

Descriptions:

The rock observed in this stop are fine grained in which grained size are not observed. These are fined grained sedimentary rocks which undergo metamorphism. In this the amounts of mica or clay minerals high. Due to metamorphism some patches were converted to phyllites and some patches were converted into schist which has garnet mineral. Basically all these sediment are a part of Jaglot Group. In this there were different Meta sediments, phyllites and schist. In these sediments the turbid tic sequences developed. These deposits cover the back arc basinal areas. At the top of this metasedimentary rock, there was also some intrusion of Kohistan batholith.Many volcanic rocks were also observed that were metamorphosed. Tufficious materials and pyroclastic materials were also observed that was metamorphosed. Pegmatite’s veins were also observed at this stop. The rocks are called Gashu volcanic rocks. These materials are metamorphosed by collision during development of Himalayas. This section was part of jaglot group which consist of

1) Thilchi formation that contain Slates and Schist.2) Gashu Concluence volcanic rocks.3) Gilgit formation that contain gneiss and schist

53

Fig# 1) Metasedimentary rocks, Thilchi.

3.3.6 Stop# 6) Near to ThilchiTime: 4:56 pm

N 35° 37' 31.0"

E 74° 36' 34.8"

Elevation: 1285m

Rocks Observed:

Green Schist.

Description:

At this stop we observed green schist. Green color is because of Chlorite or epidote. These rocks are formed by the metamorphism of pyroclastic volcanic rocks. Grade of the metamorphism was low.

Minerals observed:

Chlorite and epidote

54

Fig# 1) Green schist.

3.3.7 Stop# 7) Bunji-JaglotTime: 5:22pm

N 35° 39' 55.7"

E 74° 37' 06.3"

Elevation: 1287m

Rocks Observed:

Diorite

Description:

55

At this stop we observed coarse grain diorites. Jaglot diorite is a coarse grain diorite and this section is part of Kohistan batholith. Mafic dike is also present in the diorite.Pagmatite vein is also present which is the younger part of batholith. Minerals present in the rock are Quartz, Biotite and Garnet.

Fig# 1) Diorite along with mafic intrusion and Pegmatite vein.Munji-Jaglot

3.3.8 Stop #3.8) Junction Points of Rivers and MountainsTime: 6:10 pm

N=35̊ 44̍

E= 74̊ 35̍ 20.6̎

Elevation

56

Rocks Observed:

Granitic Rock

Descriptions:

The rocks observed in his stop were very fined grained granitic rock which is sometime also known as Athelites. It is also intruded by Kohistan batholith part, so different types of vein and dikes are formed. The rocks were basically vein or dikes .This is a massive body of rock.

The stop was also geographically important. It is a junction point of

Indus and Gilgit River

Three Mountain Ranges

a) In NW side there was Karakorum

b) In W side there was Hindukush

c) In SW side there was Himalayas

57

Fig# 1) Three mountain ranges.

Fig# 2) Rivers junction Indus and Gilgit river.

58

Fig# 4) View point of Mountain ranges and Rivers.

59

3.4 Day# 4) Gilgit to Hunza3.4.1 Stop# 1) Jutal, GilgitTime: 10:15 am

N 35° 59' 27.2"

E 74° 19' 33.1"

Elevaton: 1512m

Rocks Observed:

Granite

Description:

The rocks observed at this stop were granite, composed of biotite, quartz and feldspar. Grain size was fine to medium. This section is also part of Kohistan batholith.

Minerals Observed:

Biotite, Feldspur and Quartz

60

Fig# 1) Granite near Jutal Village, Gilgit.

3.4.2 Stop# 2) Near Nomal Time: 11:00 am

N 36° 08' 23.4"

E 74° 17' 54.2"

Elevation: 1680m

Rocks Observed:

Mafic rocks (Basalt)

Description:

At this stop we observed mafic rocks that may be basaltic rocks. Grain size was fine and foliation was present in the rocks. Green color patches were also observed that may be chlorine that form by metamorphism.Gniesstocity was also present in the rocks. Pillow structures were also observed that formed when extrusion occur in the ocean. It is also called Chalt volcanos.color of the basalt was darkish grey to black.

Minerals observed:

Chlorite

61

Fig# 1) Mafic rocks (Basalt), Nomal.

3.4.3 Stop# 3) Plate’s Collisional pointTime: 11:39 am

N 36° 14' 1.4"

E 74° 18' 26.7"

Elevation: 1761m

Plate Collisional Point:

At this we saw a junction point where two continental plates collide. This is a point where Indian plates collide with Eurasian Plates. As a result of collision the Himalayan devolved.

Rocks observed:

Quartzite

Description:

At plate collision point we observed coarse grain quartzite. This quartzite is also named as Hunza quartzite. Hunza quartzite is a part of Korakarram block. Tight fold was observed at this point. Some people mark MKT in this zone.

62

Fig# 2) Quartzite at Collisional point.

63

Fig# 3) Tight fold, Plates collisional point.

3.4.4 Stop# 4) Chalt VillageTime: 12:10 pm

N 36° 14' 14.8"

E 74° 19' 25.6"

Elevation: 1832m

Rocks Observed:

Phyllite

Description:

The rock observed at this stop is phyllites. It is fine-grained metamorphic rock formed by the reconstitution of fine-grained, parent sedimentary rocks, such as mudstones or shales. Phyllite has a marked fissility (a tendency to split into sheets or slabs) due to the parallel alignment of platy minerals; it may have a sheen on its surfaces due to tiny plates of micas. Its grain size is larger than that of slate but smaller than that of schist.Protoliths were deposited at backside of island arc. These are form by collision of plates that cause metamorphism and form phyllite.Age of this rock was cretaceous.

At this we studied that there are two zones where MKT were marked.

MKT were marked between Yasin Group and Chalt Volcanic MKT were marked where Yasin group end on Eurasian plate.

64

Fig# 1) Phyllite, Chalt village.

3.5 Day# 5) Gilgit to Besham

3.6 Day# 6) Besham to UOH

3.6.1 Stop# 1) B/W Shangla and ThakotTime: 9:17 am

N=34̊ 50̍ 47.6̎

E=72̊ 58̍ 28.8̎

Elevation =711m

Rocks Observed:

Graphite and micaceous schist

Description:

At this stop we observed Graphite schist and mica schist.at this stop we also observed Thakot fault that is basically strike slip fault and can be seen at different locations but at this stop that fault was also exposed. The amount of mica is high in rock; there is also phyletic material in it. The sequence of metamorphosed rock belonged to Pre-Cambrian age. The black color fine grain graphite’s is developed in rock.

65

Fig# 1) graphite schist and quartz vein.

Reference: 1: Self Observations.

2: Geology of Pakistan edited by F.K.Bender and H.A.Raza

66