Salt Range Field Report

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Department of Geology

Salt range Field report

Submitted to:

Sir Naveed Anjum

Sir M. Azhar

Submitted by:

AHMAD GHANI

B.S part-2

University of Peshawar

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Brief

Contents

Preface

Acknowledgments

To the teachers

Chapter 1:

Introduction

Location

Accessibility

Geology

Chapter 2:

Introduction to the study Region

Stratigraphy of the Region

Chapter 3:

Chharat Group

1. Nammal Formation

2. Sakesar Limestone

3. Chorgali Formation

Nilawahan Group

1. Tobra Formation

2. Warchha sandstone

3. Sardhai Formation

Zaluch Group

1. Amb Formation

2. Wargal Limestone

3. Chhidru Formation

The Permo-Triassic Boundry

Salt Range Formation

i. Sehwal marl member

ii. Bandarkas gypsum member

iii. Billianwala salt member

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Musakhel Group

1. Mianwali Formation

2. Tredian Formation

3. Kingriali Formation

Surghar Group

1. Datta Formation

2. Shinawari Formation

3. Samana Suk Formation

K.T Boundry

Makarwal Group

1. Hangu Formation

2. Lockhart Limestone

3. Patala Formation

Chapter4:

CREDITS

REFRENCE

DEDICATED TO

To my parents, teachers, fellows

&

All the

DIAMONDS

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Preface Our Approach

Today's students are tomorrow's decision-makers, whether their future careers

are in politics, finance, technology, medicine, geology, or other sciences. It is

their decisions that collectively will decide the fate of our planet-earth. The

instructors in Earth science or geology must ensure that their students have the

opportunity to obtain a basic understanding of the Earth so that they are

equipped to make informed, environmentally responsible decisions in their

future careers.

I will definitely say that our teachers/ instructors helped us a lot in

attaining goals that were selected for we students during salt range (lesser

Himalayas) held on 8th-11th dec. 2009. I convey the message that understanding

the Earth is exciting, and that it enriches and heightens our sense of awareness

of the world around us.

Our field to salt range was to recognize and understand various

lithologies, structures, fossils, economically important mines in the sedimentary

strata ranging from the Cambrian to recent age of the geologic time scale. If, at

the end of my report, you urge to have a glance over again, then I will have

definitely done my best job in preparing this report and achieving the goals

through the ever best help of my teachers.

Organization of the report This report is divided into four days studies of various formations, groups and

members of the formations in salt range. The salt range is basically divided into

three parts naming as eastern salt range, central salt range and western salt

range. All these four days study deals with the lithologies, structures and fossil

contents of those formations.

Acknowledgments

An undertaking such as this one is impossible to complete without the help and

expertise of many people. The team at the field encouraged and advised me

every step of the way. Their expertise and cheerfulness kept me motivated and

ensured that I completed the task at hand and made it a pleasurable experience.

My teachers Mr. Naveed anjum and M.Azhar navigated me through many of

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the members, formations and groups of the salt range and also through various

secrets of writing this report which made substantial improvements to the text

and artwork. I greatly appreciate the impressive skills of my teachers. I also

acknowledge the department of geology and university of Peshawar that helped

a lot in arranging the field for us in such crucial circumstances of our

homeland.

To my family who helped me along every step of my life and in

understanding of my geology life while I was out of the native town in field

studies and was a constant source of inspiration.

Abstract: The Salt Range contains the most important geologic and

paleontologic localities in Pakistan, and is one of the outstanding field

areas in the entire world. Despite its easy accessibility, it has a

wealth of geological and paleontological features. In fact, it represents an

open book of geology where various richly fossiliferous stratified rocks

are very well exposed due to lack of vegetation. These include the

Permian carbonate succession with its outstanding brachiopod fauna,

Lower Triassic ammonoid beds (the Mianwali Formation, formerly

known as "Ceratite Beds"), and Lower Tertiary marine strata with age

diagnostic foraminifera. These rocks also provide an excellent

opportunity for appreciation of tectonics in the field.

In addition to the easily available roadside geology,

some prominent gorges provide fantastic locations to study the

sedimentary succession. Older strata are exposed in the eastern Salt

Range between the Khewra-Choa Saidan Shah and Fort Kussak including

the famous Khewra Gorge. In the west, beyond Kallar Kahar, are younger

strata such as in the Nilawahan Gorge at Nurpur, the Nammal Gorge near

Mianwali, the Chichali Gorge near Kalabagh, and further west the

Lumshiwal Nala at Makerwal. This succession has been rightly called a

Field Museum of Geology and Paleontology and can be classified as one

of the great paleontological areas of the world, fully worthy of

conservation and protection efforts.

To the teachers We live in amazing times. In the past 20 years we have learned an enormous

amount about our Earth, and new information confronts us almost daily. We

can scarcely watch the news or read a newspaper without learning of some new

and exciting discovery related to Earth. This information had come at such a

bewildering pace, that it was difficult to assimilate it all without the help of our

teachers.

I convey that during field our teachers gave us excitement of discovery

while heightening our knowledge, appreciated us, and made us interested in the

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geologic field work and in displaying an appetite for learning more. In the near

future, we students will make decisions, big and small, that will impact the

environment on a local, regional, and even global scale. Facing to such

decisions, I hope that our teachers, in greater way, helped us in making the right

ones.

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INTRODUCTION

The Indus Basin of Pakistan is divided into two parts i.e. Lower Indus

Basin and Upper Indus Basin. The Upper Indus Basin is further divided

by Sargodha high way in to two parts. Towards the east of the Sargodha

highway is Potwar Plateau and towards the west is Kohat Plateau. The

region of the North Punjab called as Potwar Plateau, is bound in the

South by Salt range and in North by MBT as shown below.

Fig. 1. Location of the study area with reference to regional tectonic framework. The Indus River in the

east Separate Kohat from the Potwar Plateau and the MBT marks its northern extremity.

The name of Salt range was first use by ELPHISTON in 1808. The name

is derived from the fact that area contains huge reserve of the common

table salt.

Salt range is one of the few most important localities in the Sub-continent

for its interesting structural, valuable stratigraphic and paleontological

record. Salt range is characterized by extensive Anticlines folds,

Synclines folds and various types of Faults. It is also important as a

source of minerals e.g. Halite, gypsum, Coal, fire clay etc. The

occurrence of these minerals is important in stratigraphic as well as

paleontological point of view. That’s why Salt range sequence of Pakistan

has fascinitated Geologist from all over the world due to its well

preserved faunal assemblages.

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The Salt range is mainly divided into two parts. The area to the east of the

river Indus “Main Salt range” or “Cis-Indus Salt range” and the area to

the west of river Indus is called “Trans-Indus Salt range”. The main Salt

range is further divided into three parts:

Western Salt Range

Central Salt Range

Eastern Salt range.

Eastern Salt range is about 16km and its height about the sea level is

760m. The western range is widens westward to the width of about 32km

with highest attitude of 1422m at Sakessar. Similar central Salt range is

more wider then eastern and western Salt range.

The Salt range strikes almost East-West and terminates at Kalabagh

where the range is intersected by river Indus. Beyond the river Indus the

ranges beaks out into various ranges collectively referred as Trans-Indus

ranges. The rocks in the Salt ranges are generally folded and are typically

marked by large and small scale faulting as well as local over-thrusting

with movements towards south. The sedimentary sequence ranges from

Pre-Cambrian to the Eocene and recent age. It is also marked by several

unconformities.

In our field visit to the Salt range, we have visited only eastern and

western Salt range of the main Salt ranges. In the Eastern Salt range, we

studied the Khewra Gorge, while in the western Salt range we studied the

Nammal Gorge and Zaluch Nala section. We have studied the

stratigraphy and detailed litology of the various formation exposed in the

above said Gorges.

We also observed some of the very important mineral deposits e.g.

Khewra Salt mine, Coal deposits, Iron ores etc.

STRATIGRAPHY OF THE REGION

The rocks of the Salt ranges stratigraphic units ranges in the age from

Pre-Cambrian to the Tertiary with the marked absence of Ordovician ,

Silurian, Devonian and Carboniferous age throughout the region.

Locally a given stratigraphic rock sequence pinches out laterally to the

point of vanishing e.g Mesozoic sequence is well developed in the

western salt range and Trans-Indus ranges but the Triassic and Jurassic

and perhaps all the cretaceous formations are conspicuously absent in the

most of the central and eastern Salt range.

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An igneous intrusion of the younger age is also present in the Cambrian

age rock called as “Khewrite’ or “Khewra Trap”. Several types of

unconformities are also present in the area which also includes

paraconformity, Permotriassic unconformity and Permocambrian

unconformity.

We have visited the following three Gorges in the main Salt range

during our field to that region:

Khewra Gorge (Eastern Salt range)

Nammal Gorge (Western Salt range)

Zaluch Nala (Western Salt range)

The description and Stratigraphy of the above three Gorges are

explained as:

AGE GROUP &FORMATION LITHOLOGY

Pleistocene and late

pliocene

Kalabagh Conglomerates

(naushahra sandstone and

conglomerates)

Brown and gray

conglomerates with

sandstone and clay

interbeds

Major Unconformity Pliocene &

late Miocene

SIWALIK

GROUP

SOAN

light coloured sandstone &

conglomerate light red and

gray clays

Late Miocene

Dhok Pathan

Red-brown clays with gray

sandstone; conglomeratic

near Indus

Nagri

Greenish –gray sandstone

and clays; Conglomeratic

near Indus

Middle

Miocene

Chinji

Bright red clays with

sandstone

Early Miocene

Rawalpindi

GROUP

Kamlial

Massive red and brown

sandstones, dark red clays

Muree

Massive sandstones, dark

red and purplish clay-shales;

basal conglomerate

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Major Unconformity

Early

Eocene

Chharat

Group

Chor Gali

(Bhadar Beds)

Olive-green shales with

bedded Limestones

Sakesar

Massive and nodular

limestones, with marls;

chert in upper part

Nammal

Light gray calcareous

shales and limestone

Paleocene

Makarwal

Group

Patala

Green shales with coal

seam in east; thin

limestones

Lockhart

(Khairabad)

Gray, semi-nodular and

marly limestones

Hangu

(dhak pass)

Impure limestones,

sandstones, and shales,

often carbonaceous

Major Unconformity

Early

cretaceous

Surghar

group

Lumshiwal Light-colored sandstones

with carbonaceous bands

Early

cretaceous &

late Jurassic

Chichali

(belemnite beds)

Dark green to black

glauconitic shales and

sandstones

Unconformity Middle Jurassic

Baroch

Group

Samana suk

(baroch

limestones)

Gray and purple bedded

limestones with shale

interbeds

Early

Jurassic

Shinawari Alternating limestone,

shale and siltstone;

sandstone at top

Data

(variegated beds)

Sandstones with

limestones, carbonaceous

shales and lateritic zones

Unconformity

Late

Triassic

Musakhel

Group

Kingriali

(kingriali

dolomite)

Massive light colored

dolomite and dolomitic

limestones, with sandstones

Middle

Triassic

Tredian

(kingriali

sandstone)

Massive gray and purplish

sandstone, with thin

carbonaceous bands

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Early

Triassic

Mianwali

(ceratite beds)

Olive-green and gray shales

with thin limestones and

sandstones

Paraconformity

Late

Permian

Zaluch

Group

Chhidru

(Up. Productus)

Limestone, marl and

calcareous sandstone

Wargal

(Middle

Productus)

Massive gray limestones;

occasional thin

carbonaceous bands

Amb

(Lower

Productus)

Calcareous sandstone and

impure limestone;

carbonaceous shale

interbeds

Early

Permian

Nilawahan

Group

Sardhai

(Lavender clays)

Dark purple and lavender

clays with subordinate

sandstones

Warchha

(Speckled

sandstones)

Red and light colored

sandstones and grits in part

arkosic; calys interbeds

Dandot

(conularia beds)

Olive-green and gray

sandstones and shales,

occasionally carbonaceous

Tobra

(talchir

conglomerates)

Conglomeratic sandstones

and shales, boulders mainly

igneous or metamorphic

Major Unconformity

Middle

&

Early(?)

Cambrian

Jhelum

group

Jhelum

Group

Baghanwala( salt

pseudomorph

beds)

Blood-red shales and

flaggy sandstones; with salt

pseudomorphs

Jutana

(magnesian

sandstone)

Massive light-colored

dolomite and dolomitic

sandstones; subordinate

shales

Kussak

(neobolus shales)

Gray and purplish shales

and glauconitic sandstones;

pebble-bed at base

Khewra

(purple

sandstones)

Massive maroon fine-

textured sandstones;

maroon shales and flags

below

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Eocambrian

Salt Range Formation

Red gypseous marl with

rocksalt; gypsum-dolomite

above; occasional oil shale

Central Salt Range:

CHHARAT GROUP:

NAMMAL FORMATION: This formation is the first member of the Cherat group. Cherat

group represents the Eocene strata of the Salt range.

HISTORY:

“Nammal limestone and shale” by Gee (1935), “Nammal

Shale” by Danilchik and Shah (1967), is named as Nammal formation by

Stratigraphic committee of Pakistan.

LITHOLOGY:

Main lithology of this formation is shale, marl and limestone

alterations. Shale is gray to green and fossiliferrous. Lime stone is gray to

bluish, argillaceous and highly fossiliferrous. Marl is light gray to bluish

gray and is also fossiliferrous.

ENVIRONMENT OF DEPOSITION:

Environment of deposition of this formation is shallow

marine to lagoonal environment.

THICKNESS:

Thickness of this formation at its type locality is 100m.

CONTACT:

The upper contact of this formation is with overlying

Sakessar formation and is transitional and conformable. The lower

contact of this formation is with underlying Patala formation and this

contact is also conformable.

FOSSILS AND AGE:

Various fossils found in this formation are Foraminifera and

mollusks. Due to the presence of these fossils, age assigned to this

formation is Early Eocene.

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SAKESSAR LIMESTONE: This formation is the second member of the Cherat Group.

HISTORY:

“Sakessar Limestone” by Gee in 1935 was accepted by the

Stratigraphic committee of Pakistan.

LITHOLOGY:

Bulk of lithology of this formation is limestone which is cream to

light gray in color, nodular, and massive in the upper part and also highly

fossiliferrous. Light gray colored Marl is also found in the top most part

and having Chert nodules.

THICKNESS:

Thickness of this formation in Salt range is from70-150m.

CONTACT:

The upper contact is with Chorgali formation and this contact is

transitional and conformable. The lower contact is with Nammal

formation and it is also conformable.

FOSSILS AND AGE:

Various fossils

found in this formation are

Foraminifera, Mollusks

and Echinoids. Due to the

presence of these fossils,

the age assigned to this

formation is Early Eocene.

The last member of Cherat

group is missing in the

Nammal gorge. So the

Sakessar formation is the

last formation that we have seen in the Nammal gorge.

CHORGALI FORMATION: This is the 1st member of Cherat Group.

HISTORY:

“Chorgali beds” by Pascoe (1920) has been formalized as Chorgali

Formation by SCP. This formation also represents the “Passage beds” of

Pinfold (1918) in the Attock area “Badhrar beds” of Gee and Evans (in

Davies and Pinfold 1937) in the Salt Range and “Lora Formation” of

Latif (1970a) in the Hazara area.

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LOCATION & TYPE SECTION:

The section exposed in the Chorgali Pass (Lat. 33°26'30"N :

Long. 72°41'E) in the Khair-e-Murat Range, has been chosen as the type

section.

LITHOLOGY:

According to Cheema et al. (1977), the formation is

composed of shale and limestone.

In the Khair-e-Murat Range, it is divisible into two distinct units.

The lower unit comprises dolomitic limestone and shale. The upper unit

is composed predominantly of shale with one thick bed of dark grey

limestone and a bed of nodular argillaceous limestone near the top.

In Salt Range, the formation is also divisible into two parts. The

lower part consists of shale and limestone, while the upper part is mainly

limestone.

DISTRIBUTION:

The formation is distributed in the eastern Salt Range, Kala

Chitta Range, Khair-e-Murat Range and in the Hazara area.

THICKNESS:

It is 150 m thick at Chorgali Pass, 30 m in Tarki, 15m at

Bahadurkhel and about 45 m in southeastern Hazara.

CONTACT:

In the Salt Range, the formation conformably overlies the

Sakesar Limestone and at other places Margala Hill Limestone.

In the Salt Range, it is unconformably overlain by the

Murree Formation, while conformably in other areas by the Kuldana

Formation.

FOSSILS:

A rich fossil assemblage including foraminifers, mollusks

and ostracodes has been reported by Davies and Pinfold (1937), Eames

(1952), Gill (1953) and Latif (1970c).

WESTERN SALT RANGE: ZALUCH NALA: Zaluch Nala is located in the western Salt range. It is the type

locality of the Zaluch group rocks.

In this Nala we have studied

Lei Conglomerate which are Quaternary deposits.

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LEI CONGLOMERATE:

Lei conglomerates are quaternary deposits. The name “Lei

Conglomerates” was introduced by Gill in 1952 but it was earlier named

as “Boulder Conglomerate” by Pilgrim in 1910.

This conglomerate consists of poorly sorted pebbles and boulders of

mostly Eocene rocks, with a small proportion of older sedimentary rocks,

quartzites and igneous rocks. The conglomerate is intercalated with beds

of soft sandstone and siltstone of pale brown to dark brown color.

This conglomerate is different from the conglomerate of the Tobra

formation in sense that there are no bedding planes in Lei Conglomerate

but they are present in Tobra formation.

Lei conglomerates are known as FANGLOMERATES because the

environment of deposition of this formation is Fluvial.

Lei conglomerate

NILAWAHAN GROUP: These rocks are of Lower Permian age. It includes Tobra

formation, Dandot formation, Warcha Sand stone and Sardhai formation.

TOBRA FORMATION: This formation is the first member of the Neela Wahan group.

Neela Wahan group represent

the Lower Permian strata of

the Salt range.

HISTORY:

“Talchir boulder beds” by

Gee and “Talchir stage” by

Pascoe in 1959 was now

named as Tobra formation by

stratigraphic committee of

Pakistan.

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LITHOLOGY:

Main lithology of this formation is conglomerate, sandstone and shale.

Conglomerate of this formation is polymictic which means that clasts of

this formation are derived from various sources. Pink colored Granite

clasts are very common in these conglomerates which are the part of the

“Nager Parker granite” in Sindh. Metamorphic slates are also present in

this formation. Striations are also present in this formation which

indicates Glacio-Fluvial environment of deposition of this formation.

ENVIRONMENT OF DEPOSITIION:

Environment of deposition of this formation is

Glacio-Fluvial and Fluvial environment.

THICKNESS:

Thickness of

this formation is 20m in type

locality but 133m in the western

Salt range.

CONTACT:

The upper

contact of this formation is with

Dandot formation which is

transitional and conformable.

The lower contact of this

formation in Zaluch Nala is with Lei conglomerate which is an

unconformable contact.

FOSSIL AND AGE:

Various fossils reported from this formation are pollens,

spores etc. Age assigned to this formation is Lower Permian.

WARCHHA SANDSTONE: This formation is the third member of the Neela Wahan

group. The second member of this group i.e. Dandot formation is missing

in the Zaluch Nala.

HISTORY:

“Warcha Group” by Noetling (1901) is named as

Warcha Sandstone by Hussein Ahmed in 1967.

LITHOLOGY:

This formation is mostly consisting of Sandstone of red

to maroon color which indicates oxidizing conditions. Sandstone is

medium to coarse grained and mostly thick bedded and massive. Pebbles

of granite and quartzite are also present. Carbonaceous shale and coal are

also present.

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ENVIRONMENT OF DEPOSITION:

Environment of deposition of this formation is

non-marine, sub aerial to paludal.

THICKNESS:

Thickness of this formation at its type locality is 26-80m.

CONTACT:

The upper contact of this formation is with overlying Sardhai

formation which is conformable. The lower contact of this formation is

with underlying Dandot formation which is also transitional and

conformable.

FOSSIL AND AGE:

Some plants remains are found in this formation. Age

aasigned to this formation is Early Permian.

SARDHAI FORMATION: This formation is the fourth and last member of the

Neela Wahan group.

HISTORY:

“Upper part of the Warcha group” by Noetling (1901) is named

as “Lavender Clays” or “Sardhai formation” by Gee and Pascoe in1959.

LITHOLOGY:

This formation mainly consists of bluish to greenish

colored clay, minor gray sandstone and gypsum and calcareous beds in

the upper part.

ENVIRONMENT OF DEPOSITION:

Environment of deposition of this formation is very

shallow reducing marine to estuarine environment.

THICKNESS:

Thickness of this formation at its type locality is 42m

and in western Salt range its thickness is 65m.

CONTACT:

Upper contact of this formation is with overlying Amb

formation which is conformable contact. Lower contact of this formation

is with Warcha Sandstone which is also conformable.

FOSSIL AND AGE:

Brachiopods are commonly found in this formation. Age

assigned to this formation is Early Permian.

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Sardhai Clays.

ZALUCH GROUP:

AMB FORMATION: It is the first member of Zaluch Group. Zaluch group

represents the Upper Permian strata of the Salt range.

HISTORY:

“Amb sandstone beds” by Waagen (1891), “Amb

formation” by Teichert is now called as Amb formation by SCP.

LITHOLOGY:

This formation consists of thin to medium bedded

sandstone and limestone. Thin beds of shale are also present. In some

portion limestone and sandstone are mixed. When limestone is less then

sandstone, then it is called as Limy sandstone. Limestone is light grey on

fresh surface and grey to brown on weathered surface. Fractures are also

present in limestone. Thin layers of organic shale are also present in this

formation.

ENVIROMENT OF DEPOSITION:

Environment of deposition of this

formation is Shallow marine to palludal.

THICKNESS:

This formation is well developed

in the western Salt range and thin out east wards.

Thickness of this formation is 80m in type locality

and 47 m in Khisor range.

CONTACTS:

Upper contact with Wargal

limestone is conformable and the lower contact

with Sardhai formation is also conformable but

not present in the Nammal gorge.

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FOSSIL AND AGE:

This formation is highly fossiliferrous. Typical microfossils

are Forms. Most important fossil group is foraminifera. Example of this

group is fusulina which is macrofossil in this microfossil group.

Brachiopods are also present. Due to presence of these fossils the age

assigned to this formation is Upper Permian. Monodeoxydiacathonxis

(rice like fossils) also seen here.

WARGAL LIMESTONE: It is the second member of the Zaluch group.

HISTORY:

“Wargal group” by Noetling (1901), “Middle Productus

limestone” by Waagen (1879), is now called as Wargal limestone by

stratigraphic committee of Pakistan.

LITHOLOGY:

This formation is consists of limestone and dolomite.

Limestone is argillaceous, somewhat nodular, thin to medium bedded and

highly fossiliferous. Dolomite is pinkish grey in color and massive. Black

colored chert nodules are also present in it. Small scale fault is also

visible in this formation.

ENVIRONMENT OF DEPOSITION:

Environment of deposition of this formation is shallow marine

shelful, and littoral to super-0tidal environment.

THICKNESS:

This formation is well distributed in the Salt range and Khisor

Range. Its thickness in Zaluch Nala is 182m.

CONTACT:

Lower contact with Amb formation is sharp and conformable and

upper contact with Chidru formation is also transitional and conformable.

FOSSILS AND AGE:

This formation is highly fossiliferous. Various fossils found

are Brachiopods, Gastropods, Ammonoids, trilobites etc. Index specie

Productus (brachiopod) is also found abundantly in this formation. Due to

presence of these fossils age assigned to this formation is Middle

Permian.

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CHHIDRU FORMAITON: This formation is third member of Zaluch group.

HISTORY:

“Chidru beds” by Waagen (1891), “Chidru Group” by

Dunbar (1932) is now called as Chidru formation by the stratigraphic

committee of Pakistan.

LITHOLOGY:

Main lithology of this formation included limestone,

sandstone, and limy sandstone. At the base of the formation, Shale unit of

grey to dark grey color is also present. The upper most part has well

marked Sandstone bed, which is the marker horizon and distinguishing

character of this formation.

ENVIRONMENT OF DEPOSITION:

Environment of deposition of this formation is shallow

marine, littoral to palludal.

THICKNESS:

This formation is well distributed in the western Salt

ranges and Trans Indus ranges. Its average thickness at the type locality is

64m.

CONTACT:

The lower contact of this formation with Wargal

limestone is conformable and transitional. The upper contact with

Mianwali formation is disconformable.

FOSSILE AND AGE:Various fossils reported from Chidru formation

are Brachiopods and ammonoites. Due to the presence of these fossils age

assigned to this formation is Late Permian.

THE PERMO-TRIASSIC BOUNDARY: (The passage of Marine Permian to Marine Triassic)

The Permian rocks located in the Salt Range have

richness of fauna and having relationship with the rocks of Triassic

system, the strata near the Permo-Triassic boundary are marine and

having conformable relationship but there is significant break in the fauna

at the contact.

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Kummel and Teichert in 1966 referred to the body as Paraconformity

showing sub-Arial exposure at the end of the Permian time. In support to

this view, they thoroughly studied the contact throughout the Salt range to

find out the lithological and textural changes across the boundary. Their

work is briefly summarized as under. The upper most lithological unit of

Chidru formation is sandstone bed called as white sandstone bed. The

sandstone is fine to medium grained, thinly bedded with interbeds of

shale while the upper contact with Kathwai member of Mianwali

formation is dolomite.

The Permo-Triassic boundary is marked by the following properties:

There is abrupt change in the lithology at the boundary of the two system

i.e. white sandstone of Upper Permian and dolomite at the base of

Triassic.

The upper most sandstone bed shows decrease in faunal contents which

indicate change in depositional environment during the deposition of

white sandstone bed. Kathwai member on the other hand also lack fossils,

indicating shallow intertidal environment.

The variation in thickness of white sandstone bed indicates time gap

between Permian and Triassic rocks.

SALT RANGE FORMATION: It is the oldest and only Pre-Cambrian age formation

exposed in the Khewra Gorge. It has three members:

Sehwal marl member:

This member is further divide into two parts:

It consists of dull red marl beds with some salt seems. Thick beds of

Gypsum are also found. Thickness of this part is >40m.

It consists of the bright red marl beds with irregular gypsum. KHEWRA

TRAP is also present in this part. Thickness of this part is 3-100m.

Bandarkas Gypsum member:

It is mainly massive gypsum with some salt seems. Minor beds of

dolomite and clay are also present. Its thickness is >80m.

Billianwala Salt member:

It consists of Ferrogenous red marl with thick seems of salt. Its thickness

is >650m.

Conjugate fractures are present in all the members.

CONTACT:

Lower contact of the Salt range formation is not exposed but in some oil

wells crystalline basement rocks are found. The upper contact with the

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Khewra sandstone of Jehlum group is conformable. Thickness of this

formation is >830m.

ENVIROMENT OF DEPOSITION:

Environment of deposition is restricted basin condition with high rate of

evaporation and climate is hot and arid.

Salt Range Formation.

KHEWRA TRAP:

Khewra trap is highly weathered igneous body about 6m

thick present in the upper member of the Salt rage formation. It is purple

to green in color. Characteristic feature is that it consists of highly

decomposed radiating needles of light colored Pyroxene mineral. Its

origin is crustal thinning due to normal faulting.

MUSAKHEL GROUP:

MIANWALI FORMATION: It is the first member of the Musa Khel group. Musa Khel

group represents the Triassic strata of the Salt range.

HISTORY:

“Lower part of Mianwali series” by Gee (1959), “Top most

limestone and dolomite beds” by Waagen (1879) was named as

“Mianwali formation” by Kummel in (1969).

LITHOLOGY:

This formation is mainly composed of limestone, siltstone,

dolomite, shale and sandstone. This formation is divided into three

members:

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Kathwai member: It is the lower most part of the Mianwali formation and

mainly consist of crystalline dolomite and interbedding of Shale.

Mitti wala member: It is the middle part of the Mianwali formation and consists

of green shale beds with sandstone and limestone interbedded.

Narmia member: It is the lower most member of the Mianwali formation and

mainly consists of sandy dolomite, and dark gray to brown color

limestone. Sandstone interbeds are also found in this part.

ENVIRONMENT OF DEPOSITION:

Environment of deposition of this formation is open

marine to deltaic environment.

THICKNESS:

Thickness of this formation is 127m.

CONTACT:

The lower contact with Chhidru formation is marked

by Paraconformity and the upper contact with overlying Tredian

formation is sharp, well defined and conformable.

FOSSIL AND AGE:

The various fossils found in this formation are

ceratites (cephalopod), brachiopods, and conodonts. Due to the presence

of these fossils the age assigned to this formation is Lower Triassic.

TREDIAN FORMATION: It is the second member of the Musa Khel group.

HISTORY:

“Kingriali Sandstone” by Gee (1948), is called as “Tredian

formation” by Kummel and Gee in 1966.

LITHOLOGY:

Main lithology of this formation is sandstone, which is

medium to thick bedded and upper part is massive. Few beds of shale,

siltstone and sandy limestone are also found.

ENVIRONMENT OF DEPOSITION:

Environment of deposition of this formation is shallow

marine to deltaic.

THICKNESS:

The thickness of this formation in Zaluch Nala is 76m.

CONTACT:

Lower contact with Mianwali formation is sharp, well-

defined and conformable. The upper contact with Kingriali formation is

also gradational and conformable.

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FOSSIL AND AGE:

The various fossils found in this formation are plant

microfossils. Due to the presence of these fossils the age assigned to this

formation is Middle Triassic.

Contact between Tredian and Kingrilai Formations

KINGRIALI FORMATION: It is the third and last member of the Musakhel group.

HISTORY:

“Kingriali Dolomite” by Gee (1943) is named by Gee again

in 1945 as “Kingriali formation”.

LITHOLOGY:

The bulk of lithology is dolomite, dolomitic limestone with

interbeds of dolomitic shale. The dolomite is thin to medium bedded, fine

grained with inter beds of shale and marl. Cross beds are also present in

this formation.

ENVIRONMENT OF DEPOSITION:

Environment of deposition of this formation is shallow

marine environment.

THICKNESS:

The average thickness of this formation is 76-106m.

CONTACT:

Lower contact of this formation is with Tredian formation

and is conformable. Upper contact is with Datta formation of Jurassic age

and the contact is Disconformity.

FOSSIL AND AGE:

Poorly preserved Brachiopods, Bivalves, and crinoids are

present in this formation. Age assigned to this formation is Early Triassic.

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SURGHAR GROUP:

DATTA FORMATION: This formation is the first member of the Surgher Group.

Surgher group represents the Jurassic and Cretaceous strata of the Salt

Range.

HISTORY:

“Variegated stages” by Gee

(1945), “Lower part of Samana beds” by

Davies (1930) is named as “Datta

formation” by Danilchik in1961.

LITHOLOGY:

Variegated beds of

sandstone, siltstone and shale of different

colors are present in this formation.

Sandstone is red to maroon, grey, green and

white in color. Shale, siltstone and

mudstone are irregularly distributed. In the upper part thick beds of

maroon shale are also present. Sulpher is mostly present in this formation

indicating swamp or deltaic environment.

ENVIRONMENT OF DEPOSITION:

Environment of deposition of

this formation is very shallow marine to

deltaic and alluvial plains.

THICKNESS:

Thickness of formation at its

type locality is 212m.

CONTACT:

Upper contact of this

formation with overlying Shinawri formation

is gradational and conformable. Lower contact

with underlying Kingriali formation is

disconformable.

FOSSIL AND AGE:

This formation is poorly fossiliferrous but some petrified

wood is present there. Age assigned to this formation is Jurassic.

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SHINAWARI FORMATION: This formation is the second member of the Sur Gher group.

HISTORY:

“Lowest Samana Beds” by Davies (1930), “Lower part of

Kyoto Limestone” by cutler (1933), is named as Shinawri formation by

Fatmi in 1961.

LITHOLOGY:

Main lithology of this formation is medium to coarse

bedded limestone which is of gray to brownish gray color. It is well

bedded, sandy, oolitic with nodular marl, shale and sandstone. Lime stone

in the lower part has thick sandstone bed in middle and maroon shale in

the upper part.

ENVIRONMENT OF DEPOSITION:

Environment of deposition of this formation is shallow

marine, deltaic, tidal flats and estuarine environment.

THICKNESS:

Thickness of this formation at type locality is 400m.

CONTACT:

Upper contact of this formation is with overlying Samana

Suk formation and is transitional and conformable .Lower contact with

underlying Datta formation is also Conformable.

FOSSIL AND AGE:

Various fossils found in this formation are Ammonoites,

Brachiopods and corals. Due to the presence of these fossils age assigned

to this formation is Middle Jurassic.

SAMANA SUK FORMATION: This formation is third member of Sur Gher group. Few beds

of this formation are present in Nammal gorge but it is undifferentiated

from the Shinawri formation.

HISTORY:

“Bared limestone” by Gee, “Upper part of Kyoto limestone”

by Cutler (1933) is named as Samana Suk formation by Davies in 1930.

LITHOLOGY:

Main lithology of this formation is medium to thick bedded

limestone of gray to dark gray color. This limestone is oolitic with shale

beds with subordinate marl and calcareous shale.

ENVIRONMENT OF DEPOSITION:

Environment of deposition this formation is shallow marine

shelful to supertidal environment.

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THICKNESS:

Thickness of this formation at type locality is 186m.

CONTACT:

Lower contact of this formation with underlying Shinawri

formation is conformable and upper contact with overlying Chichali

formation is disconformable.

FOSSIL AND AGE:

Various fossils found in this formation are Brachiopods,

bivalves, Gastropods and Crinoids. Due to presence of these fossils age

assigned to this formation is Middle Jurassic.

The rest of the three members of Sur Gher group i.e. Chichali formation,

Lumshiwal formation and Kawagarh formation are absent in along a

major unconformity Named as K.T Boundary.

K.T BOUNDARY: (Cretaceous-Tertiary Boundary)

At the end of the Mesozoic era and before the beginning

of the Cenozoic era, there was a major Disconformity in geologic history.

If we study the rocks of the Paleocene age, we find a total displacement

of almost all the life on earth. The dinosaurs, plants, invertebrates etc. all

are disappeared. This major Disconformity is seen all over the world. It is

represented in Pakistan in the form of the laterite bed at the bottom of the

Hangu formations as we go from Kawagarh formation within Hangu

formation. In the lower Indus basin, it is represented between the Moro

group and Ranikot group.

Scientists all over the world have presented their ideas on

this matter out of which three are well known.

Meteorite impact theory:

According to this a meteorite stuck the earth near the Gulf

of Mexico. As a result a huge cloud rose which block the sun rays from

reaching the earth’s surface. As a result all living creatures died due to

their dependence on sunlight as a primary source of energy.

Volcanic activity:

According to this theory, during this period repeated

volcanic activity cause the formation of the huge dust clouds. Eventually

blocking sunlight and other sources, thus causing the death of the living

creatures on the earth.

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Change in the earth’s Magnetic field:

According to this theory, the sudden reversal of the earth’s

magnetism distributed the living systems, which could not adjust to the

new magnetic field and thus resulted in the death of all the living

organisms.

After this event some of the organisms survived. Thus these organisms

are seen nowadays having different structural features as compared to

these before this event.

MAKARWAL GROUP:

HANGU FORMATION: This formation is the first member of the Makarwal group.

Makarwal group represents the Paleocene strata of the Salt range.

HISTORY:

The “Hangu Shale” and “Hangu Sandstone” by Davies

(1930) have been formalized by the stratigraphic committee of Pakistan

as Hangu formation.

LITHOLOGY:

This formation consists of dark grey, rarely variegated

sandstone, shale, carbonaceous shale, and some nodular argillaceous

limestone. The sandstone is white, light gray, and reddish brown,

weathers dark rusty

brown, fine to coarse

grained and medium to

thick bedded.

THICKNESS:

In the

Salt range area this

formation is 40 to 45m

thick.

CONTACT:

The upper

contact of this

formation is with

Lockhart formation and this contact is transitional and conformable. The

upper contact of this formation is with Samana Suk formation and this

contact is unconformable.

FOSSILS AND AGE:

The various fossils found in this formation are foraminifera

with some corals, gastropods and bivalves. Due to the presence of these

fossils, the age assigned to this formation is Paleocene.

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LOCKHART FORMATION: This formation is the second member of the Makarwal Group.

HISTORY:

Davis (1930) introduced the term Lockhart Limestone for a

paleocene limestone unit in the kohat area.

LITHOLOGY:

Grey to dark gray, medium to thick massive bedded, brecciated

limestone. The limestone displays very well developed nodularity. The

nodularity may be caused by any of the following four reasons.

Organic activity

Differential compaction

Pressure solution

Stretching

ENVIRONMENT OF DEPOSITION:

The environment of deposition is shallow marine shelf

conditions where calcite is precipated in warm water to form limestone.

THICKNESS:

In the Samana Range the formation is 60 meter thick.

CONTACT:

The upper contact with Patala formation is transitional and

conformable. The lower contact is with Hangu formation and the contact

is also conformable.

FOSSILS AND AGE:

The limestone contains abundant foraminifers, corals,

mollucs, Echinoids and algea. On the basis of these fossils the age of the

formation is assigned as Middle Paleocene.

PATALA FORMATION: This formation is the third member of Makarwal group.

HISTORY:

Davies Pinfold (1937) named it as Patala shale which later

was renamed as the Patala Formation by the SCP.

LITHOLOGY:

Alternate beds of Shale, Clay and limestone. Thin bedded

sandstone and some interbedded marl and conglomerate are also present.

ENVIRONMENT OF DEPOSITION:

The environment of deposition is transitional, continental and

deltaic marine environment.

THICKNESS:

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Type locality is in Patala nala located in the salt range area,

where the thickness of the formation is 90 meters.

CONTACTS:

The upper contact with overlying Nammal formation is

transitional and conformable. The lower contact is with Lockhart

formation and it is also transitional and conformable.

FOSSILS AND AGE:

The formation is richly fossiliferrous and contains abundant

foraminifera and mollusks. On the basis of the above mentioned fauna,

the age assigned to this formation is Late Paleocene.

۞ CREDITS ۞ With the Grace of ALLAH (THE most merciful

and beneficent ) I have completed my this report of Salt Range Field.

This all credit goes to my dear Parents, respected Teachers and fellows

who always remembered me in their prayers, guided me through their

best and gave me a backup while doing this tough job.

I want to thank them all.

REFRENCE: 1. The Geological Survey of Pakistan (volume 22)

2. Stratigraphy of Pakistan – by S.M.Ibrahim Shah

3. www.brooks/cole.com/geology

4. www.mcgraw-hill.co.uk/geology

5. www.gsp.gov.pk/pakistan/index.html

6. www.wikipedia.com/geology