Final

WITH THE NAME OF ALLAH WHO IS THE MOST BENIFICIENT AND THE MOST MERCIFUL

I

TOPIC:

Geological Field Report on Choa Saidan Shah – Khewra Road section, Salt Range and Rumli Area, Marglla Hills,

Islamabad.

SUBMITTED BY : Umair Asad

ROLL NO. : BGLF08M049

SUBMITTED TO : Syed Haroon Ali Shah

CLASS : BS-Geology

SEMESTER : 6TH

II

G EOLOGICAL FIELD REPORT

Litho structural mapping and stratigraphy of Khewra to Choa sedan road section in salt range and Rumli area in Hazara basin, near Quaid-e-Azam University Islamabad.

III

A BSTRACT This field work has completed in two parts. The first part is completed from

22nd March, 2012 to 25th March 2012.During these days we stayed at youth hostel Katas and got the understanding of the structures and stratigraphy along Khewra to Choa sedan shah road. This area is geologically in Salt range. Salt range is further divided into three parts. Eastern salt range , Central salt range , Western salt range. Our field area is situated in central salt range. The salt range of Pakistan forms part of sub-Himalayan mountains which stretch for more than 180 kilometer east-west between the Jhelum and Indus river along the southern margin of potwar basin. With in the salt range we can observe the sedimentary cover from Pre-Cambrian to recent deposits. Our field area is in central salt range which is from Khewra to Warcha.

The second part of the field is completed during 30 March 2012 to 1 April 2012.The field area is Rumli village near Quaid-e-Azam University Islamabad in Margalla hills situated in hazara basin. Hazara basin is situated in north of Pakistan. Hazara range is the northern most part of sedimentary succession of the north western margin of the Indian plate. It is bounded by its north by Panjal thrust on its southern side by the main boundary thrust. The main highway from Rawalpindi to Peshawar is the dividing line between the western limit of the Hazara and the Kala Chita range. Rumli area is in Hazara Basin. Whenever we move toward north side of Pakistan the deformation in rocks increase extensively because of the strengthen forces acting from the north side. Rumli area is situated near MBT therefore extensive deformations found here in rocks and more complex are the structures. Due to compressional forces more Thrust Faults are encountered in this area.

IV

A CKNOWLEDGEMENT

First of all I would like to thanks to ALLAH almighty that enable me to do this difficult

task. Then thanks to my respectable teacher Mr. Syed Haroon Ali Shah because of his

great interest in this field provision and effort to manage this field in the quite tense and

security threats atmosphere. I also thanks to my parents who never left me alone in any

problem of life and all those peoples who help me to complete this work including my

group members and the University Management to providing the traveling facilities.

UMAIR ASAD

BGLF08M049

BS GEOLOGY 6th SEMESTER

V

F IELD BRIEFINGS Department of Earth Sciences University of Sargodha arranged a field trip for B.S. Geology 6TH

semester from March 22 to 25, 2012. The field trip was related to the litho structural mapping and the stratigraphic understandings of the project area.

Studied Area

During this field we study the road sections along Khewra to Chua Sedan shah. And the road sections from Quaid-e-Azam University to Rumli village in Margalla hills.

Objectives

1. Recognition of formation.2. Study of geological structure.3. Finding the environment of deposition.4. Lithologic Mapping of formations along road sections.

Methodology

1. Collecting samples2. Photography3. Measuring of dip & strike4. Mapping

Sporting material

1. Geological hammer2. Branton3. Lens4. Camera

VI

T ABLE OF CONTENTS

Part 1 Introduction to salt range ____________________________ 10-11 Previous work______________________________________ 12 Tectonic framework of salt range_______________________ 13 Tectonic map of Pakistan_____________________________ 14 Stratigraphy of salt range______________________________ 15-16 Stratigraphic sequence of Salt range_____________________ 17-18 Observed sequence of Salt range

Khewra Formation_________________________________ 20 Kussak Formation__________________________________ 21 Jutana Formation__________________________________ 22 Baghanwala Formation and its associated structures_____ 23-27 Tobra Formation__________________________________ 28 Dandot Formation_________________________________ 29 Warcha Sandstone_________________________________ 30 Nammal Formation__________________________________ 31 Sakesar Formation__________________________________ 32

Faults that were observed during field in Salt range Normal fault between Nammal and Sakesar Fomations______ 33 Normal Fault between Nammal and Tobra Formations_____ 33 Horst and Graben structures at Pidh village_____________ 34 Karangal Thruust near Choa Sedan Shah________________35

VII

Part 2 Introduction to Margalla Mountain ranges___________________ 37 Tectonic frame work specially emphasized on MBT____________ 37-38 List of observed sequence in Rumli section___________________ 39

Lokhart Limestone_____________________________________40 Patala Formation______________________________________41 Margalla hills Limestone________________________________42 Chorgali Formation____________________________________43 Kuldana Formation____________________________________44 Murree Formation and its associated structures____________ 45-49

Geological structures that were observed during our field in Rumli section_________________________________________ 50-52

Refrences_____________________________________________ 53

VIII

P ART – 1 LITHO STRUCTURAL MAPPING AND STRATIGRAPHIC UNDERSTANDING ALONG THE CHUA SEDAN SHAH ROAD SECTION IN EASTERN SALT RANGE.

I NTRODUCTION

The Salt Range is the south-facing scarp of the Potwar Plateau. Salt range is further divided into three parts.

IX

Eastern Salt Range: Eastern Salt Range is from Jhelum to Chakwal.

Central Salt Range: Central Salt Range is from Chakwal to Khushab.

Western Salt Range: Western Salt Range is from Khushab to Mianwali.

Our field area is situated in Eastern Salt range. We observe the formations along Khewra to Chua sedan shah road section. The salt range of Pakistan forms part of sub-Himalayan mountains which stretch for more than 180 kilometer east-west between the Jhelum and Indus river along the southern margin of potwar Basin. Within the salt range we can observe the sedimentary cover from Pre Cambrian to recent deposits. Rocks of Salt range was uplifted by a thrust fault called Salt Range thrust, which emplace older rocks of salt range upon younger rocks of less deformed tertiary rocks of Jhelum plain. The incline of the strata in the central part is around 100, and in the western, eastern, and northern parts it is up to 450 It derives its name from extensive deposits of rock salt that form one of the richest salt fields in the world; they are of Precambrian age and range up to more than 1,600 feet (490 m) in thickness. The range is approximately 186 miles (300 km) long from east to west, and its width, in the central and eastern parts, is from 5 to 19 miles. Its average height is 2,200 feet, and its highest altitude, at Sakesar Mountain, is 4,992 feet (1,522 m). In addition to the salt-deposits, mined from ancient times, the Salt Range contains coal, gypsum, and other minerals. The salt range and its trans Indus extensions bridges the reentrant between the outer range of North Western Himalayas and the Suleiman mountain arc upper proterozoic to recent deposits occur in salt range prior to quaternary time only epirogenic forces effect the region accompanying occasionally by the wrapping.

X

The Salt Range exposes a good sedimentary succession but has a long gap between the Cambrian and the Upper Carboniferous, and short gaps below the Upper Jurassic, below the Eocene, and below the Upper Oligocene.

Salt diaphism:

As less dense material move up ward w. r. t to high dense material, salt range formation is composed of salt which are low dense than overlying rock so it move toward low pressure state. Due which all the overlying material (formations) get exposed. This process is called Salt diaphism.

XI

P REVIOUS WORK Salt Range has great interest for the geologists from all over the world to study

the complete sequence from Precambrian to recent, the Permian-Triassic boundary, and Lower Tertiary foraminifer’s biostratigraphy. Of particular note is the great work of E.R. GEE (1 935, 1945. His initial work related to solving the problem of the age of the ''Saline Series'', a discussion of that time, and he made a great contribution by producing a geological map (more recently six sheets on a scale 1:50,000 have been published by the Geological Survey of Pakistan excluding the Trans-Indus Surghar Range). DAVIES and PINFOLD (1937) completed a comprehensive study of Lower Tertiary larger foraminifera of the Salt Range. WAAGEN (1882- 1885, 1895) worked on the brachiopods of the Permian of the Salt Range and FATIMI (1973) studied the certitudes of the Triassic of the Salt Range and Trans-Indus Surghar Range. He also worked on Stratigraphic nomenclature on the Salt Range as did SHAH (1 977). KUMMEL and TEICHERT (1966, 1970) illustrated Permian brachiopods and described the detailed stratigraphy of the Permian rocks while GRANT (1966) described trilobites. HAQUE (1956) described the smaller foraminifera from the Tertiary formations of the western Mammal Gorge, Salt Range. AFZAL (1997) completed his doctoral thesis on the planktonic foraminifera of the Paleogene and established a plank tonic biostratigraphy for the Patala Formation of the Salt Range and Surghar Range (AFZAL & von DANIELS, 1991; AFZAL & BUTT, 2000). SAMEENI (1997) completed his doctoral thesis on the Paleogene biostratigraphy of the Salt Range under UNESCO IGCP-286, headed by Prof. Lukas HOTTINGER of Basel University, Switzerland, and established an alveolinid biostratigraphy for the Eocene succession of the Salt Range (SAMEENI & BUTT, 1996, 2004; SAMEENI & HOTTINGER (2003).

XII

T ectonic Framework of Salt Range

“Salt range and Trans Indus ranges are the surface expression of leading edge of a decoloment thrust in which the crystalline basement is not involved”. The zone of decoloment appears to have been provided by Salt Range Formation which underlies the salt range and the pot war plateau to the north.

Compression forces are mostly responsible of orogeny. If we notice the tectonic of Himalaya in Pakistan, we can classify the Himalaya on the basis of

STRATIGRAPHY STRUCTURES METAMORPHISM

The main classification of Himalaya is as:

SUB HIMALAYA:

It is area comprised between Salt range thrust (SRT) and main boundary thrust (MBT). Along the MBT a thrust fault is passing named as Punjal thrust. In the south of Punjal thrust area consists of sedimentary rocks or soft rocks called southern sedimentary zone. In the north of Punjal fault area consists of igneous/metamorphic rocks or hard rocks called as northern igneous/metamorphic zone.

LESSER HIMALAYA:

It is area comprised between main boundary thrust (MBT) and main central thrust (MCT).

HIGHER HIMALAYA: It is area bounded between the main central thrust (MCT) and the main mantel

thrust (MMT).Above MMT, MKT exists in north. Salt Range exists in the south of MBT and Hazara basin exists in the west of MBT or Hazara-Kashmir syntax.

XIII

T ECTO NIC MAP

OF AKISTAN

XIV

S TRATIGRAPHY OF SALT RANGE

The hill ranges making the Southern boundary of Potwar Plateau lying between the river Indus in the west and river Jhelum in the east is called Salt Range. The Salt Range is a hill system in the Punjab province of Pakistan, deriving its name from its extensive deposits of rock salt. The range extends from the Jhelum River to the Indus, across the northern portion of the Punjab province. The Salt Range contains the great mines of Mayo, Khewra, Warcha and Kalabagh which yield vast supplies of salt. Coal of a medium quality is also found.

Sakesar and Tilla Jogian are the highest peaks of Salt Range. Khabikki Lake and Uchhali Lake are the lakes of Salt Range.

The area displays some excellent geological exposures in valley and gorges representing geological history from 600m years to recent and therefore is known as field museum of Geology.

Geologically the Salt range is famous for the rocks exposed from 600 million years old to present i.e. from Cambrian to recent with the absence of Ordovician, Silurian and Devonian over a distance of few kilometers. Salt Range is divided into three parts.

o Eastern Salt Range: Eastern Salt Range is from Jhelum to Chakwal.o Central Salt Range: Central Salt Range is from Chakwal to Khushab.o Western Salt Range: Western Salt Range is from Khushab to Mianwali.

PROCESSES OF FORMATION OF SALT RANGE

Indian plate collusion Salt diaphism

XV

Indian plate collusion:

As Pangaea spilt into Paleozoic era, its one part move toward north, called leisure and other toward south called Gondwanaland. In Permian Gondwanaland split in different plates. One of the plate called Indian plate start moving towards north, This plate then collide with the belt of island arcs, called semiarid arc, which are form by partial melting of oceanic lithosphere, this cause a thrust faults, called Main mantel thrust or MMT.

In 25 Ma ago, due to collusion intercontinental fault Main Central thrust or MCT developed. In 10Ma ago another intercontinental fault occur called Main boundary Thrust and in 5 Ma ago Salt range thrust or SRT form.

Salt diaphism :

As less dense material move up ward w. r. t to high dense material, salt range formation is composed of salt which are low dense than overlying rock so it move toward low pressure state. Due which all the overlying material (formations) get exposed. This process is called Salt diaphism.

XVI

S TRATIGRAPHIC SEQUENCE OF SALT

RANGE

FORMATIONS AGE

Lei conglomerate PleistoceneSoan formation

Late MiocenePliocene

Dhok pathan formationNagri formationChingi formation

Kumlial formation Early MioceneMurree formation Early Miocene

MAJOR UNCONFORMITY

Chorgali formation Early EoceneSakesar formation Early EoceneNammal formation Early Eocene

Patala formation PaleoceneLockhart limestone Paleocene

Hangu formation Paleocene

MAJOR UNCONFORMITY

Lumshiwal formation Late Jurassic & Early CretaceousChichali formation

DISCONFORMITY

Samanasuk formation Middle JurassicShinawri formation Middle Jurassic

Datta formation Middle JurassicKingriali formation Late JurassicTredian formation Late Jurassic

Mianwali formation Late Jurassic

DISCONFORMITY

PARACONFORMITY

Chidhru formation Late PermianWarghal limestone Late Permian

Abm formation Late PermianSardhai formation Early Permian

Warchha formation Early PermianDandot formation Early PermianTobra formation Early Permian

MAJOR UNCONFORMITYBaghanwala formation

Middle & Early CambrianJutana formationKussak formationKhewra sandstone

Salt Range formation Precambrian to Early Cambrian

L IST OF OBSERVED FORMATIONS DURING FIELD WORK

ALONG KHEWRA TO CHUA SEDAN SHAH ROAD SECTIONS.

Kamlial Formation Miocene

Sakesar limestone Early Eocene

Nammal formation Early Eocene

Warcha formation Early PermianDandot formation Early PermianTobra formation Early Permian

Baghanwala formation Middle to Early CambrianJutana formation Middle to Early CambrianKussak formation Middle to Early Cambrian

Khewra sand stone Middle to Early Cambrian

K HEWRA SANDSTONE

Synonymy: The name was originally proposed by Noetling (1894) as “Khewra group”. Prior to

that Wynne (1878) called the Formation as “Purple sandstone series”. The present Name “Khewra Sandstone” was given by Stratigraphic Committee of Pakistan.

Observed lithology:

It was mainly composed of beds of purple, dull red fine grained sand stone.

Contacts:

Lower contact:Lower contact of Khewra sandstone is sedimentary with salt range formation.

Upper contact: Upper contact of Khewra sandstone is conformable with kussak formation. Contact is shown in this fig 1.

Age:

The age of formation is Early Cambrian.

1

K USSAK FORMATION

Synonymy:

Wynne (1878) applied the name of “Obolus beds” or “Siphonotreta beds” to predominantly greenish grey glauconitic micaceus sand stone and silt stone. Waagen (1895) used the name “Neobolus beds” for the same unit. The present name was given by Stratigraphic Committee of Pakistan.

Field lithology:

Kussak formation consists of predominantly sandstone and siltstone. Sandstone and siltstone are micaceous, glauconitic, greenish grey in color, some dolomite content is present. In the upper part variegated sandstone and sandy shales are interbeded.

Contacts:

o Lower contact: Lower contact is conformable with the Khewra sandstone

o Upper contact: Upper contact is gradational with jutana formation.

Age:

Early to late Cambrian.

J UTANA FORMATION

Synonymy: Fleming (1853) named this unit “Magnesium sandstone” and Noetling (1894) as “Jutana stage”. The Stratigraphic Committee of Pakistan formalized the name as “Jutana Formation.

Field lithology :

It is mainly composed of pink to light yellow green fine grained dolomite. As shown in fig 2.

Contacts: o Lower contact:

Lower contact is gradational with Jutana formation.o Upper contact:

Upper contact is conformable with Baghanwala formation. Age:

The Formation assigned Early Cambrian to Early Middle Cambrian age.

B AGHANWALA FORMATION

Synonymy:

The name Baghanwala Formation is now given to the rocks of the Pseudomorph Salt Crystal zone of Wynee (1878) and the Baghanwala Group of Noetling (1894). Holland (1926) called these beds salt Pseudomorph beds and Pascoe (1959) named them Baghanwala Stage.

Field lithology:

Thin bed, maroon colored sandstone with clay interbeds. Shale’s found in some part. Pseudo-morph crystals (of salt and lenticular bedding are also observed. As shown in fig 3.

Contacts: Contacts are shown in fig 4.

o Lower contact: The lower contact with the Jutana formation is conformable.

o Upper contact:

2

Upper contact is unconformable with Tobra Fm.

Age:

Since it rests conformably on the Jutana Formation which considered as Early Middle Cambrian age, the same age may be assigned to Baghanwala Formation.

Geologic structure: o Graben:

A graben is a block of rock which is bounded on both sides by the Normal fault. A graben is found in the Baghanwala formation and can seen in the fig 5.

5

4 3

o Salt pseudomorph:

Crystal salt pseudo morph. Salt pseudomorph crystals are shown in fig no 6 these formed in supratidal environment when water dissolve the salt evaporates crystals and deposit here clay and silt as shown in Fig 6.

o Flaser bedding:

Flaser bedding is formed when alternate bed of sand and mud are deposited and they formed in high energy environments or tidal environment. Flaser bedding is found in Baghanwala formation. Flaser bedding consists mostly of sand. Sand > mud is shown in Fig 7.

6

7

o Channel migration:

Channel migration is found in the Baghanwala formation on road section as shown in Fig 8.

o Channelize Sandstone: Sandstone of channel deposition is found in the lower part of formation as shown in Fig 9.

o Lenticular bedding:

Lenticular bedding is sedimentary bedding pattern displaying the alternating layers of mud and sand formed during periods of slack water.

8

9

lenticular bedding is classified by its large quantities of mud relative to sand. The sand within bedding displays lens like shape and it shows high energy environments such as intertidal and supra tidal. Mud > sand is shown in Fig 10.

o Tidal bedding:

The sedimentary structure within the intertidal sediments is tidal bedding. This consists of sand-mud couplets as shown in Fig 11.

10

11

T OBRA FORMATION

Synonymy:

The name Tobra formation was previously known as Talchir Boulder Bed or Talchir Stage of Gee (1959) and salt range boulder bed of Teichert (1967).

Field lithology:

It is tillitic facies. Boulders of pink granite with biotitic and Muscovite and some other fragments are embedded in clayey, sandy and silly matrix.

o Pink Granites:Pink Granites are the special features of Tobra formation.

o Special feature:This is a tilitic facies Glacier deposits no sorting is a feature of this formation shown in figure 5.

Contacts:

o Lower contact: Lower unconformable with Baghanwala Fm.

o Upper contact: Upper contact is gradational with Dandot Fm shown in the following figure

no 12.

Age The age of Tobra formation is early Permian.

D AN DONT

FORMATION

Synonymy:

Dandot Group” by Noetling(1901) , “Olive Series” , “Eurydesma Beds” and “Conularia beds” by Wynne(1878) and the “Speckled Sandstone” by Wagon(1879).

Field lithology:

Tobra formation has been observed along Choa saidan shah road. It was observed that the section consists of thick bedded sand stone with pebble of

12

different sizes. Lower part is composed of shale’s. Shale’s are splintery and dark to greenish grey in color. Upper part is composed of gritty sandstone with occasionally pebble beds. Sandstone is yellowish grey in color.

Contacts: o Lower contact:

The formation is gradational contact with the underlying Tobra formationo Upper contact:

It has sharp but conformable contact with overlying Warcha Sandstone. Age:

The age of the Dandot Formation on the basis of fauna and its super positional order with the Tobra Formation of Early Permian age is considered as Early Permian.

Field feature:

Channel migration is found in the Dandot formation near Pidh village on road section as shown in Fig 13.

W A RCHA

SANDSTONE Synonymy:

The name Warcha Sandstone was coined by Hussain (1967) which has been approved by stratigraphic committee of Pakistan.

Lithology:

13

The formation consists of medium to coarse grained sandstone, conglomeratic in places and interbeds of shale. The sandstone is cross bedded and arkoses. The pebbles of the unit are mostly of granite of pink color and of quartzite as shown in Fig 14.

Contacts:

o Lower contact:

It conformably overlies the Dandot Formation.

o Upper contact: It is overlain by the Sardhai Formation with the transitional contact.

Age : The age is Early Permian.

N AMMAL FORMATION

Synonymy:

The term Nammal formation has been formally accepted by Stratigraphic committee of Pakistan for the ''Nammal Limestone'' and ''Shale'' of Gee (1945).The section exposed in Nammal gorge is type section.

14

Lithology: It consists of yellowish shales. Nodular limestone of light grey to creamy color also exists. Limestone is thin bedded. Interbeds of limestone and shales are also observed as shown in Fig 15.

Contact: o Lower contact:

The lower contact of nammal formation is with Patala formation.

o Upper contact: Upper contact of nammal formation is with the Sakesar limestone are transitional.

Age: Eocene age has been assigned to the formation on the basis of fauna.

S AKE SAR

FORMATION

Synonymy:

15

The term ''Sakesar Limestone'' was introduced by Gee for the most prominent Eocene limestone unit in Salt range and Trans Indus ranges.

Observed Lithology: Sakesar formation was observed in Eastern salt range along Chua Sadden Shah road during our Field work. Creamish colored, massive nodular limestone with nodules of chert in upper part was observed. In Nammal Gorge chert beds and marl in upper part of Sakesar limestone. Nummulities and Assilina are highly abundant in Sakesar limestone.

Field Features: o Chert noduleso Nummulites

Contact:

The lower contact with the Nammal Formation is conformable. In eastern salt range, the upper contact with Chorgali formation is conformable, whereas in central and western salt range, the Rawalpindi or Siwalik groups uncomfortably

overlie the formation.

Age: The age of formation is regarded as Early Eocene on the basis of foraminifers reported.

FAULTS OBSERVED DURING FIELD IN SALT RANGE

Normal fault:

When the block lying above F.P moves in the dip of fault plane this is called normal fault. Sakesar lime stone found equal to Warcha sand stone. The age of Sakesar limestone is Miocene and the age of Warcha sand stone is early Permian. So this is a normal fault. Where the Nammal formation move downward under the influence of gravity. This fault is observed along the Chua sedan shah to Khewra road section can seen in Fig 16.

Normal fault occur between Nammal formation and tobra formation. Nammal formation found equal to Tobra formation in previous figure. This can seen in Fig 17.

Horst and Grabben:

16

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Horst and graben are terms referring to regions that lie between normal faults

and are either above or lower than the area beyond the faults. A horst represents a block pushed upward by the faulting, and a graben is a block that has dropped due to the faulting.

18

We have seen in the field a horst and grabben structure between Sakeser limestone and Warcha sand stone at Pidh village. Basically this village is located on grabben. Sakeser limestone making graben and village is Constructed on the Sakeser limestone as shown in fig 18.

Karangal thrust:

Thrust is a type of fault in which repetition of strata occurs and the block lying above fault plane moves across the dip direction of fault plane. Karangal thrust is a thrust that observed in field near “Saraen More”1 Km away from Chua Sedan shah. This thrust lies between the Kamlial formation overlain by Salt range Formation. The age of Kamlial is late Miocene and the age of Salt range Formation is Eocambrian. Basically this is a splay of Salt range Thrust. Karangal thrust run north to South. Gandala nala thrust and Karangal thrust are truncated along Strike slip fault which is situated under the city Chua sedan shah. Thrust can seen in Fig 19.

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PART-2LITHO STRUCTURAL MAPPING AND

STRATIGRAPHIC UNDERSTANDING IN RUMLI AREA IN HAZARA BASIN

I NTRODUCTION

M ARGALLA MOUNTAIN RANGES

The Margalla hills also called Margalla mountain ranges are also a part of lesser Himalayas located north of Islamabad. Margalla range has an area of 12605 hectors. The hills are the part of Murree hills. It is arrange with many valleys as well as high mountains.

The hill range nestles between an elevation of 685 meters at the western end and 1604 meters on its east with average height of 1000 meters. Its highest peak is Tilla Charouni. The range gets snow fall in winters.

The hills rock formations are 40 Million years old and the fossils of marine life are abound Indicated that the Margalla hills were at one time under the Sea.

According to the research carried out by scientists and Archeologists of the project “post earthquake explorations of human remains in Margalla hills”, the formation of the Margalla hills dates to Miocene epoch. The dominant limestone of Margalla hills mix with sandstone and occasional minor beds of shale. The

archaeologists of the project have also found two Human foot prints over 1 Million years old here preserved in sandstone.

Tectonic framework:

The field area is near Islamabad, Rumli section which is situated almost near to MBT also called Muree Fault. Along the MBT a thrust fault is passing named as Punjal thrust.MBT formed 10 Million years ago by the collision of Indian plate with Eurasian plate and it is an intercontinental fault developed. In the south of Punjal thrust area consists of sedimentary rocks or soft rocks called southern sedimentary zone. In the north of Punjal fault area consists of igneous/metamorphic rocks or hard rock’s called as northern igneous/metamorphic zone.In the mapping of MBT we see a fold in MBT called as Hazara-Kashmir syntaxes.In this section complex Folding and Thrusting can seen because we are close to Northern area collision zone.Fault scarp of MBT can seen in the Fig 20.

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L ist of Observed Formations in Rumli section

The following formations were observed in Rumli section.

Recent conglomerates HoloceneMurree formation MioceneKuldana Formation EoceneChorgali Formation Eocene

Margala hill formation EocenePatala formation Paleocene

Lokhart limestone Paleocene

S TRATIGRAPHIC NOTES

L OCKART FORMATION

Synonymy:

Davies introduced the name ''Lockhart Limestone'' for a Paleocene limestone unit in the Kohat Area (1930). This unit thus represents ''Nummulitic series'' of Middle Miss (1896). Latif (1970) Assigned Mari Limestone to this unit.

Field Lithology :

In the Hazara the limestone is dark grey and black in color and contains intercalation of marl and shale. Lockhart limestone also has some tectonic nodules as shown in Fig 21.

Contacts:

o Lower contact: The formation conformably overlies the Hangu Formation

o Upper contact: The formation transitionally underlies Patala Formation

Age: The formation is of Paleocene age.

P AT ALA

FORMATION Synonymy:

Patala Shales” by Davies (1937), “Tarkhobi Shales” by Eames (1952), “Hill Limestone” by Wynne (1873). The present name was given by Stratigraphic Committee of Pakistan.

Field lithology: In Nammal Gorge it is mainly composed of khaki and blackish brown colored

shales as shown in Fig 22. Contacts:

o Lower contact:Lower disconformable with Lokhart afaormation.

o Upper contact:Upper conformable with Margalla hills limestone.

Age : Upper Paleocene age.

21

22

M ARGALA HILL LIMESTONE Synonymy:

The term Margala Hill limestone of Latif has been formally accepted by Stratigraphic committee of Pakistan for the ''Nimmulitic formation'' of Waagen and Wynee (1872), the upper part of Hill limestone of Wynne(1873) and Cotter (1933), and part of ''Nummlitic Series'' of Middle miss .The name is derived from the Margala Hills in Hazara.

Field lithology: Margala hill limestone was observed in Rumli road section during our field

work. It was limestone with subordinate shale and marl as shown in Fig 23.

Contacts: o Upper contact:

The upper contact of Margalla hill limestone is with Kuldana formation.

o Upper contact:The lower contact of margalla hill limestone is with Patala formation.

Age: The age of Margalla hill

limestone is Eocene.

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C HORGALI FORMATION

Synonymy :

The term “Chorgali beds” of Pascoe 1920 has been formalized as Chorgali Formation by the Stratigraphic committee of Pakistan.

Field lithology :

Formation is composed of shale and limestone as show in Fig 24.

Contacts :

o Upper contact:

Its upper contact is conformable with Margalla hill limestone.

o Lower contact:Its lower contact is conformable with Kuldana Formation.

Age :The age of Formation is

Early Eocene.

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K ULDANA FORMATION Synonymy:

Middle miss (1896) used the name ''Kuldana series'', Latif called ''Kuldana beds'' to the rocks of Kuldana formation.

Field lithology Murree formation was observed in Islamabad and Changla Gali during our

field work. It was clay and sandstone with conglomerate as shown in Fig 25. Contacts :

o Upper contactIts upper contact is disconformable with Murree Formation.

o Lower contactLower contact is conformable with Chorgali Formation.

Age: The fauna indicates an early Miocene age of the formation.

25

M URREE FORMATION Synonymy:

Mari Group by Wynne (1874) Murree Beds by Lydekker (1876)Murree Series by Pilgrim (1910)Murree Formation by Stratigraphic Committee of Pakistan

Field lithology: The formation consists of purple clay and greenish grey sandstone with

subordinate intraformational conglomerate. The basal strata of the formation consist of light greenish, grey calcareous sandstone and conglomerate. The formation uncomfortably overlies various formation of Eocene age. Fig 26.

Contacts: o Lower contact:o Its lower unconformable contact is with various formations of Eocene ageo Upper contact:

Upper contact is transitional with Kumlial Formation.

Age: Early Miocene age.

Associated structures: Plumose structure. Fig 27. Sole marks. Fig 28. Jointing. Fig 29. Calcite and Quartz veins. Fig 30. Trace fossils. Fig 31.

Honey comb weathering. Fig 32.

o Plumose structure: On the surface of master joint, a ridge like tracing in a plume like pattern usuallt oriented parallel to the upper and lower surfaces of the constituent rock units as shown in the fig 27

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27

o Sole marks: An irregularity or penetration on the undersurface of a sedimentary

stratum as shown in figure 28

o Joints :A fracture or crack in a rock mass along which no appreciable movement

has occurred as shown in figure 29

28

29

o Calcite and Quartz veins: When discontinuities of rocks are filled with external material like Quartz and

Veins. These things may be precipitated during the Digenesis as shown in the fig 30

o Trace fossils :Imprints of ancient animals. The trace fossils of the Mammals are found in

the Murree Formation.

30

31

o Honey comb weathering : Weathering on the upper surface of the rock just like Honey comb structure.

o Unconformity : An unconformity is found on the upper contact of the Murree Formation where it overlies by the recent conglomerates as shown in the fig 33.

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33

o Cross bedding A Characteristics sedimentary structure shows the change of current

direction during the deposition of rocks as shown in fig 34.

G EOLOGICAL STRUCTURES OBSERVED IN RUMLI SECTION

Imbrications faults: When we cut the rocks into slices this is called Imbrication. During our field in Rumli area we have seen imbrications between Lockhart limestone and Patala formation where a backthrust is found then the epitation of strata found and Duplexes are formed.These can seen in Fig 35 where 1 is Patala Fm and 2 is Lockhart Fm.

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35

First thrust marks in Rumli area : This thrust fault observed in Rumli section between the Chorgali Formation and Kuldana Formation. This is an thrust fault in which Chorgali Formation is over lie and the kuldana Formation is under lying. This can seen in Fig 36.

Graded bedding :

The graded bedding is the primary depositional structure which forms when cycle of deposition occurs and we found the fining upward sequence again and again. This is called graded bedding. This can be seen in Fig 37.

Composite unconformity :

36

37

Unconformity is a surface of erosion or non deposition and marks a hiatus in the deposition. Composit unconformity is a type of unconformity in which two Formations are underlying by the same Formation. In this case the upper formation is recent conglomerates. This can be seen in Fig 38.

Folding:

When compression forces acts then the rocks are bended and this bending is called folding of rocks. Folds are of many Types depends upon the intensity of acting forces and the nature of rocks upon which these forces are acting. The folds we have seen in the field are of following types.

o Chevron folds :Hinge point is pointed.

o Class 1-b type : Parallel folds are called 1-b type.

o Asymmetrical folds: The fold which the limbs are not the Mirror image of each other, axial plane is vertical.

o Dome structure :Dome is a deformational feature consisting of symmetrically-dipping anticlines their general outline on a geologic map is circular or oval. The strata in a dome are up warped in the center; if the top of a dome is eroded off, the result will be a series of concentric strata that grow progressively older from the outside-in, with the oldest rocks exposed at the center.

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R EFERENCES

MEMOIRS of The Geological Survey of Pakistan Vol.12 Edited by Syed Ibrahim Shah.

Internet source.

o www.wikipedia.com

o www.encyclopedia.com

o onlinelibrary.wiley.com

Geological field report of salt range and hazara by our seniors.

Encarta 2012

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