1

CHAPTER 1

1.INTRODUCTION

This trip is part of our BS and valued 3 credit hours. The trip was arranged from 20 th

November to 23th November, 2013. Our targeted location was Salt Range and the main

objective was to study and have the overview picture of Stratigraphical and Geological

features of that region. On the field we used:

i. HCl to differentiate between dolomite and limestone as limestone fizzes

on applying HCl

ii. Brunton Compass to take dip and strike

iii. Hand lens for studying different lithologies and fossils

iv. Geological hammer for collecting samples

v. Scale

We stayed at the Kallar Kahar. We went there through buses hired by university. The

journey was pleasant and smooth. The field which we visited was unsteady and rocky.

Pakistan is full of beautiful mountain ranges like, Himalaya, Hindukush, and

Karakorum. There are many other ranges in Pakistan which are full of geological

features. Pakistan is the best place to study the geological structure, history and ages. The

salt range of Pakistan is good for studying the geological ages. The name of Salt Range

was first use by ELPHISTON in 1813. The name is derived from the fact that area

contains huge reserve of the common table salt. The East-West trending fold belt

comprises the low rolling hills and valleys of the uplifted Kohat-Potwar Plateau, The Salt

Range and its Westward extensions. It is 85 km wide and extends for about 200 km. It is

a discrete structural zone bounded in the north by the north-dipping Main Boundary

Thrust (Sarwar et al. 1979; Yeats et al. 1984; Coward et al. 1985). Southward the Salt

Range Thrust, Kalabagh Fault and the Surghar Thrustfrom its southern boundary. West

and eastward it is terminated by the N-S oriented Kurram Thrust and Jehlum Fault

respectively (Kazmi and Raza 1982). The Salt range is mainly divided into two parts.

(Sajjad el al., 2005)

2

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 are called “Trans-Indus Salt range”. The main Salt

range is further divided into three parts:

(a) Western Salt Range

(b) Central Salt Range

(c) Eastern Salt range

Map 1. Western and Eastern part of Salt Range.

1.1 OBJECTIVE

The objectives for field trip were to

i. Study and observe the Lithology

ii. Sedimentary structures

iii. Rock types and contacts 

3

iv. We have studied the stratigraphy and detailed lithology of the various

formations.

1.2 SCOPE OF STUDY

On field the scope of our study was to study:

(a) Attitude of formation

(b) Stratigraphical relationship

(c) Lithological units

(d) Sedimentary structures

(e) Interruption in sequences

(f) Planning of Electric Resistivity Survey

(g) Survey Designing - Grid

(h) Acquisition of VES Data

1.3 LOCATION OF THE AREA

Kallar Kahar is a union council and subdivision of Chakwal District in Punjab,

Pakistan. It is a tourist destination and is notable for its natural gardens, peacocks and a

saltwater lake. Kallar Kahar Lake is a small brackish lake in the Salt Range, with an area

of 85 ha. The Kallar Kahar Lake is located in District Chakwal, Punjab Province at a

distance of 25 km north to Chakwal city. Kallar Kahar Lake is situated at a distance of

about 135 km from Rawalpindi via Chakwal road whereas 100km from Islamabad by

Motorway to the south and from Chakwal it is about 30kms to the south-west on

Chakwal-Sargodha road. It is located between 32° 46’ 30.31” North latitude and 72° 42’

23.80” East longitude at an altitude of 554 m above sea level. The lake is located at the

edge of Potwar Plateau and the Salt Range. (Arshad, 2006)

4

Map 2. shows Location of Study area.

1.4 ACCESSIBLITY

The Salt Range is connected to major cities of Pakistan through National Highway

and Motorway. The Eastern Salt Range is accessible from Kallar Kahar. The route

undertaken for this field trip, starting from Islamabad via Motorway to Kallar Kahar can

be seen in (Figure 1.3)

Map 3. s showing the Route undertaken for the Filed Trip starting from Islamabad to Kallar Kahar

5

1.5 GEOMORPHOLOGY AND SOILS OF SALT RANGE

Sedimentary rocks and preserved fossil records portray a complete picture of

geological and biological history of the region. The severe tilting of these rocks during

geological ages resulted in the exposure of these layers near the surface at many places

(Shaw, 1989). Aridity prevailing in the area for major part of the year is the main

climatic characteristic that affects its soils. This has resulted in limiting the soil moisture

and scantiness of vegetative cover. The over use of vegetation has accelerated rates of

erosion, resulting in bare sheet rocks devoid of any soil layers. The rocks are composed

of limestone and sandstone or both. At some places infertile red marl is exposed due to

similar reasons and the steep geological tilt resulting in frequent slips. Soils in Salt

Range are rich in basic (rock salt) but poor in Nitrogenous matter. The exposed salt rocks

get dissolved in water on rainy occasion and this dissolved salt later on deposits on

faraway soil during runoff. The area is rich in minerals e.g. salt, coal, lime, different

kinds of clay and gypsum. (Arshad, 2006)

1.6 VEGETATION

The vegetation of the area is dry-sub tropical evergreen scrub forests

characterized by open grasslands intermingled with scattered shrubs and dwarf tree

species. Vegetation of the area is divided into two main categories:

1.7 TERRESTRIAL VEGETATION

Terrestrial vegetation of Lake Kallar Kahar of the Salt Range was studied during

2007. The vegetation of the area is subtropical scrub type with scattered broad-leaved

trees, shrubs and a basal grass cover. However the vegetation around the lake was

modified due to abundant soil moisture and water salinity.

1.8 GEOGRAPHY

Geographically the Salt Range is located between 32° 23 – 33° 00 N and 71° 30 –

73° 30 East. This area is of prime importance as it is located between the Thar Desert in

the west and the Potohar plateau in the north east (Mc Kerrow et al., (1992), Yeats et al.,

(1984). Salt Range covers an area of 150 miles from east to west. It takes its name from

6

important salt deposits, which are present at Khewra, Khatha, Warcha and Kala Bagh

(Ahmad 1964, Ahmad et al., 2007). The range of hills extends in irregular arc from east

of Jhelum River in the Tilla Jogian and Bakrala ridges. It runs southwards to the north of

Jhelum River for some distance before turning North West to cross the River Indus near

Kala Bagh. On the west of river Indus Salt Range continuous southwards to the districts

of Bannu and D.I.Khan .

1.9 WATER RESOURCES

Salt Range runs in two parallel lines of hills separated by a distance of about 5 miles.

These hills consist of a number of parallel ridges. These ridges include several high level

valleys. The water from these hills finds no outlet and is collected in the valleys forming

salt lakes. There are four lakes i.e. Kallar Kahar Lake which lies close to northern slope

of range in District Chakwal. Uchali, Khabaki and Jahlar lakes are present in soon

valley, District Khushab (Ahmad, 1964). These lakes are of prime importance as these

wet lands are the winter sites of rare or vulnerable water fowls, specially the white

headed duck (Nawazish et al, 2006).

The wells situated with a short distance of these salt lakes have sweet drinking water,

showing that the saline water of lakes does not affect the underground water (Ahmad,

1964). There are streams in the area, which flow between the mountains, near Sodhi and

anhati. The nearby areas are irrigated by this water. (Arshad, 2006)

1.10 CLIMATE OF THE REGION

The climate of the area is sub-humid sub-tropical continental type with hot to

moderate summer and severe winter. The thirty-year average precipitation was 853 mm

for the Salt Range region but is estimated 500 mm for Kallar Kahar. There are two

distinct rainy seasons: the summer season or the monsoon rains start by about mid-July

and last until the mid of September. Most of the precipitation is received during July,

August and September. The winter rains begin in January and persist up to beginning of

March. May is the driest month of the year. The mean monthly temperature varies

7

between 5.9 - 38.4 °C, January being the coldest and June the hottest month of the year.

During winters the temperature often drops to below zero, usually in December and

January. (Arshad, 2006)

8

CHAPTER 2

2.1 HISTORY OF SALT RANGE

The name “Salt Range” was first used by Mounstaurt Elphinstone, a British envoy

to the Court of Kabul, who traveled from 1808 to 1815 across the territory. He noted the

extraction of Salt in the area and hence named it as “Salt Range”. The Salt Range is a

175 km east-northeast trending rampart that juts out over fluvial plain of the Jhelum

River. The Range is a broad U-shaped belt of Pre-Cambrian to Eocene strata south of

Potwar Plateau and largely east of the Indus River and North West of River Jhelum.

Map 2.1 Showing the Salt Range, Kohat Potwar Plateau, Jhelum fault and Main Boundary Thrust (MBT).

The deformed foreland rocks of the northern Indian cratonic foreland basin are

marked by Main Boundary Thrust (MBT) in the south. The MBT system contains highly

deformed Pre-Cambrian to Cenozoic sedimentary rocks, which progressively become

9

younger southward. The Kohat-Potwar foreland basin contains deformed Paleocene-

Pleistocene sedimentary sequence bounded towards south by the Salt Range Thrust

(SRT) in Potwar Plateau and the southern boundary of the Trans-Indus Ranges and the

unreformed Bannu Basin in Kohat Plateau. The undeformed foreland of the Indo-

Gangatic plain lies south of the Salt Range Thrust (SRT).

Due to the excellent exposures and a more or less complete stratigraphic sequence

of Phanerozoic rocks, the area is rightly called as “Field Museum of Geology”.

Internationally it has generated interest among the scientists for its Permian / Triassic

boundary, Pre-Cambrian – Cambrian sequence and abundance of Permian, Mesozoic and

Tertiary fauna.

Salt-Range facies in the Kohat area are more basin ward and were affected in the Early to

Middle Eocene during the early stages of the Himalayan orogeny. The unconformity

predictions and stratigraphic chart helped in the under- standing of the regional geology

and were key to the sequence and seismic stratigraphy.

2.2 PREVIOUS WORK

In the Salt Range, the pioneering work is done by E.R. Gee (1935, 1945) who

dedicated almost his entire geological career to the study of the salt Range. His work was

related to solving the controversy regarding the age of the “S aline Series” and producing

a geological map.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 ceratitids 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 (1977). Kummel and Telchert

(1966, 1970) illustrated Permian brachiopods and described the detailed stratigraphy of

the Permian rocks while Grant (1966) described trillobites. Haque (1956) described the

smaller foraminifera from the Tertiary formations of the western Nammal Gorge, Salt

Range. Afzal (1997) completed his doctoral thesis on the planktonic foraminifera of the

Paleogene and establshed a planktonic biostratigraphy for the Patala Formation of the

Salt Range and Surghar Range (Afzal & von Danials, 1991: Afzal & Butt, 2000).

10

Sameeni (1997) completed his doctoral thesis on the Paleogene biostratlgraphy of the Salt

Range under UNESCO IGCP-286, headed by Prof. Lukas Hotinger of Basel Unlversity,

Switzerland, and established an alveolinid biosstratigraphy for the Eocene succession of

the salt Range (Sameeni & Butt, 1996, 2004; Sameeni & Hotfinger. 2003). Ashraf and

Bhatti (1991) worked on the nannofossils of the Patala and Nammal Formations of the

Khairabad area of the western Salt Range.

2.3 REGIONAL GEOLOGICAL SETTINGS & TECTONICS

At the Salt Range front, Eocambrian evapontes and overlying strata override

synorogenic fan material and alluvium (Yeats et al.,1984). The strongly emergrnt central

Salt Range is located between a weakly emergent thrust front at the Surghar Range and a

buried thrust front in the easternmost Salt Range (termrnology of Morley, 1986). The

right -lateral Kalabagh tear fault terminates the Salt Range to the west (Yeats and

Lawrence, 1984). In contrast, the eastern termination of the Salt Range is divided into several

fault blocks bounded by forward and rearward-verging thrusts (Johnson et al., 1986). The Salt

Range lies about 80 km outboard of thrusting in the northern Potwar deformed zone; the

intervening Soan syncline is relatively undeformed.The northern flank of the central Salt Range is

an eroded monocline that flattens northward into the southern limb of the Soan syncline. The

monocline is the surface expression of a footwall ramp, identified by reflection profiles as a

normal fault with a basement offset of 1 km down-to-the-north (Lillie and Yousuf, 1986). The

most likely hypothesis for the origin of the down-to-the-north basement fault are:

1. extension related to Eocambrian rifting that may have accompanied the formation of evaporite

basins on the northwestern margin of the Indian subcontinent.

2. Neogene normal faulting related to flexure as the origin is loaded by thrust sheets from the

north (Lillie and Yousuf, 1986; Duroy, 1986) .

The basement offset apparently acted as a buttress that controlled ramping and

emplacement

of the Salt Range thrust sheet. The Salt Range is underlain by salt, which appears to have

flowed from beneath synclines (cf. Davis and Engelder, 1985; Fox 1983), as suggested by the

presence of more than 2 km of allochthonous salt at the bottom of the Dhariala well(Gee,

11

1983)

Map 2.2 Tectonic Model

2.4 GENERAL GEOLOGY OF THE AREA

This east west trending fold belt comprises the low rolling hills and valleys of

uplifted Kohat-Potwar Plateau, the Salt Range and westward extensions. It is about 85km

wide and extends for about 200km. It is a discrete structural zone bounded in the north by

north dipping Main Boundary Thrust. Southward the Salt Range Thrust, Kalabagh Fault

and Surghar Thrust from southern boundary. West and eastward it is terminated by

Kurram Thrust and Jhelum Fault. (Kazmi & Jan).

2.5 Generalized Lithologies

12

2.6 DISTRIBUTION AND NATURE OF PRINCIPAL STRATIGRAPHY

13

A sedimentary sequence ranging from Eocambrian to Recent is exposed in the

Salt Range and Kohat-Potwar Plateau. The exposures of Mesozoic and earlier rocks are

largely confined to the southern margin of Salt Range, Surghar Range and Khisor Range.

These comprise Eocambrian evaporites (Salt Range Formation) and shallow marine to

non-marine lower to Middle Cambrian sequence of dolomites, shales and sandstone

(Jhelum Group) that are unconformably overlain by a thick Permian clastic and carbonate

succession (Nilawahan and Zaluch Groups).

The angular unconformity at the base of Permian is characterized by the wide

spread Tilchar boulder beds (Tobra Formation). A Para conformity separates the

Mesozoic shelf (Tredian and Datta Formations) and shallow marine deposits (Mianwali,

Kingriali, Shinwari, and Samana Suk Formations from Paleozoic Sequence. The exposed

Mesozoic sequence is thickest in the western Salt Range which is more then 1,000m thick

but it has been greatly attenuated eastward due to erosion and overlap by Cenozoic

sequence. There are minor unconformities indicating disruption in sedimentation and in

the foreland sedimentary basin during the Mesozoic.

The Cenozoic sedimentary rocks consist of a 125 to 400m thick Paleogene

sequence, deposited in various types of environments, ranging from shallow marine

(Lockhart, Nammal, Sakesar, Chorgali, Kohat Formations), marine to continental

(Hangu, Kuldana Formations), marine to logoonal (Patala Formation).

In the western Salt Range, there is a significant angular unconformity above the

Cretaceous. In the western part of Salt Range there is angular unconformity (Surghar and

Khisor Ranges) they overlie Triassic/Jurassic rocks. The stratigraphic sequence is highly

fossiliferous.

14

CHAPTER 3

3.1 STRATIGRAPHY OF SALT RANGE

Exposed stratigraphic sequence in the vicinity of Zaluch Nala consists of about

one and half km thick succession of rocks of Eocambrian to Eocene age (Figure 3). The

Salt Range Formation that is the oldest rock sequence in the area represents the

Eocambrian sequence. The Tobra Formation of the Nilawahan Group marks the base of

the Permian sequence in the study area and grades upward into medium- to coarse-

grained Warchha Sandstone, whereas Dandot Formation is missing in the area. The

Warcha Sandstone is overlain by the Sardhai Formation with a transitional contact and is

placed at the top of the highest massive sandstone bed and grades upward into the Amb

Formation, which is composed of sandy limestone, gray in color and medium- to thick-

bedded. The Amb Formation having a conformable contact grade upward into the Wargal

Formation. It grades into the overlying Chhidru Formation which is Para conformably

overlain by the Mianwali Formation of early Triassic age. The upper contact of the

Mianwali Formation is marked by the Tredian Formation, which consists of sandstone,

shale and dolomite. The Tredian Formation is conformably overlain by Kingriali

Formation, which is composed of dolomite and dolomitic limestone. The upper contact of

the Kingriali Formation with the Data Formation is disconformable.

TABLE 3.2. STRATIGRAPHICAL STUDY OF THE SATLT RANGE AND

NAMMAL GORGE

Salt Range represents the escarpment running south of Potwar, where the rocks

are generally dipping to the north. It exposes rocks ranging in age from Precambrian to

Miocene. Most of these rocks i.e those belonging to Miocene, Eocene, Paleocene,

Permian, Cambrian, under Potwar, are found to be hydrocarbon bearing.

15

16

Formations Type Locality Thick-ness Lithology Fossils Age Environ

ment

S

I

W

A

L

I

K

G

R

O

U

P

S

O

A

N

Gali jagir-sihal road,

near Mujahad

village, North of

Soan

river,Campbell-pur,

Punjab.

120-450 m Conglomerate with

subordinate interbeds of

sandstone, siltstone/

clay.

Clay and sandstone

intercalated.

Vertebrates

Poorly-

fossiliferous

Late

Pliocene-

Early

Pleistocen

e

Terrestrial

DHO-K

PAT-

HAN

Dhok Pathan

village,

Campbellpur,

Punjab.

1330 m Monotonous cyclic

alterations of sandstone

& clay.

Vertebrates Middle

Pliocene

Terrestrial

NAG-RI

Nagri village

Campbellpur Disst,

Punjab.

300-1200

m

Sandstone with

subordinate clay &

conglomerate.

Vertebrates

Crocodiles

Early

Pliocene

Terrestrial

C

H

I

N

J

I

South of Chinji,

Campbellpur,

Punjab.

750 m Red clay & subordinate

brown grey sandstone

(Argillaceous facies)

Vertebrates

Crocodiles

Turtles

Lizards

Aquatic birds

Water deer

Late

Miocene

Terrestrial

R

A

W

A

L

P

I

N

D

I

G

R

O

U

P

KAM-

LIAL

Kamlial in

Campbellpur

district.

90 Purple gray & dark

brick red sandstone and

interbeds of hard purple

shale and purple

Intraformational

conglomerates.

Spheroidal weathering

& heavy minerals.

(Tourmaline)

Mammalian

fossils

Middle-

late

Miocene

Continent

al fluvial

MUR-

RE

Dhok Maiki in

Campbellpur

district.

180-600 Dark red & purple clay

and purple gray &

greenish gray sandstone

with subordinate

intraformational

conglomerates.

Plant remains

Silicified wood

Fish remains

Frogs

Mammalian

bones

Early

Eocene

Continent

al fluvial

CHORG-ALLI Chorgali Pass in 150 Shale and limestone. Foraminiferas Early Shallow-

17

CHAPTER 4

Field work

DAY 1:

LOCATION: First Location of our field was Karoli Village. The coordinate of karoli

village are:

Lat: 320 40” 52.066’N

Long: 720 46 “ 25.798’ E

Our field teachers are Dr. Anwar Qadir and sir Amjid Raees told us about the Salt

Range. Sir Anwar Qadir told us that it is formed due to coliision of plates. The Salt

Range Formation is mainly divided into three units as follows.

(i) Eastern Salt Range

18

(ii) Western Salt Range

(iii) Southern Salt Range

Point 1

we observed limestone, It was yellowish in color. It also has sandstone beds and is nodular. It has parallel bedding. There is also transitional contact between limestone and clay. Lime stone contains fossils of Assilina and Numulites.which are observed with the help of a Hand Lens.

Fig 1. Showing Limestone.

Point 2

At point two we observed another lithologywhich are composed of clayey

sandstone. Its color is maroon and is coarse grained. There is a sharp contact between

point one limestone andpoint two clay. The limestone beds are assive here.

19

Fig 2. Showing Clayey Sandstone.

Point 3

Here we observed well sorted Warcha Sandstone. There is contact between limestone, sandstone and clay. The clay is maroon in color and the shale is very thinly laminated. We also measured bed thickness and the change in lithology which is given in the table below.

20

Fig 3. Showing contact of limestone, sandstone and clay.

Table 1

S.No of Beds

Bed Thickness

Sorting Grain Size Structures Color

1 3 feet Well Sorted Coarse Cross bedding

Brown

2 1feet Well Sorted Medium Nill Rusty3 3 -17 feet Well-

Medium sorted

Medium Nill Greenish

4 1 feet 2 inches

Medium sorted

Finefine-Medium

Nill Brownish

5 8 feet Medium sorted

Medium Crosss bedding

Grey

6 3 feet Poorly sorted

Fine-Medium

Nill Brownish Black

7 7 feet Poor- Coarse Nill Grey

21

Medium sorted

8 2 feet Poorly sorted

Fine Nill Grey

9 3 feet Well sorted. Medium Cross bedding

Brown

Location 2

Point 1

At location two on point one we observed Patala Shale. It contains lamination.

Due to stresses microfoldings are also present. The shale contain black organic matter.

Fig 4. Showing Patala Shale.

Point 2

At point two we observed medium to coarse grained sandstone which are well

sorted and is brownish black in color. It also contains chert nodulues. It has parallel and

22

conjugate joints. Sir told us to measure the Dip and Strike of the strata, which are as

follows.

Dip: 240 SW

Strike: S 670 E

Fig 5. Showing Conjugate fractures in sandstone.

We also took section measurement here which is given below.

Table 2

S.No of Beds

Thickness of beds

Sorting Grain Size Structures Color

1 2 feet Poorly Sorted

Fine Nill Whitish

2 2 feet Poorly Sorted

Medium Ripple Marks

Grey

23

3 6 feet Well Sorted Fine Nill Grey4 8 feet Medium

SortedFine Nill Brownish

5 2 feet Poor-Medium Sorted

Coarse Nill Grey

6 3 feet Medium Sorted

Fine Nill Brownish

7 3 feet Medium Sorted

Fine Lineations Dark Brown

8 4 feet Well Sorted Medium Lineations Yellowish9 2 feet Medium

SortedMedium Ripple

MarksWhitish

10 1 feet Poorly Sorted

Coarse Nill Grey

Location 3

Here we observed Tobra formation. It is brownish in color. It is characterized by

its characteristic feature which is that it has conglomerates.

Location 4

Here we observed Jutana Dolomite of light color which are thinly bedded. At the

same location we also observed Baghanwala Sandstone. Its fresh color is greenish and its

weathered color is grey. It has lamination, bedding and also cliffs. Beside this formation

there is a sequence of the following formations.

24

Fig 6. Jutana Dolomite

At the top is Baghanwala Formation, below it is Juttana Formation, below it is

Kussak Formation and below it is Khewra Sandstone.

On its opposite side is Punjab Plain, which is separated from the rest of the Strata

by the Salt Range Thrust.

DAY 2:

25

STOP 1 LOCATION

Our first stop one location was at Namal Gorge of Western Salt Range. Its coordinates

are as follows.

Lat: 320 4” 5’ N

Long: 710 47” 14’ E

Stop 1

we observed Wargal Limestone of light green color. It contains conjugate joints

and nodules. We also observed some fossilized shells there. We also measured the dip

and strike of the strata which is as follows.

Fig 7. Showing Wargal Limestone.

Strike: N 230 E

Dip: 240 SW

26

Location 2

Coordinates are :

Lat: 320 39” 14’ N

Long: 710 47” 38.9’ E

Point 1

On point one we observed shale which is grey in color and has organic materials.

It seems to be coal. There are contacts in which limestone overlies sandstone and

sandstone overlies shale.

Fig 8. Showing Shale.

Point 2

Here we observed Kalabagh member of Wargal Limestone. Using Hand lens we observed different fossils like Brachiopods, gastropods and productus.

27

Fig 9. Showing Wargal Limestone.

Point 3

we observed shale of Tridian Formation. It is grey to greenish in color. It is thinly

laminated and is friable.

28

Fig 10. Showing lineation inTridian Sandstone.

Point 4

we observed Mianwali Formation which is composed of sandstone of brownish

color. we also measured the dip and strike of the strata, which are as follows.

This formation is divided into the following three members.

(i) Nermain Member

(ii) Mittiwali Member

(iii) Katwai Member

29

Fig 11. Showing Mianwali Formation.

Point 5

At point five we observed Kingriali Dolomite of Triassic age. Here sulphur is

released . some oil seepages are also present in this area.

30

Fig 12. Showing oil seepage.

Point 6Here we observed Datta Sandstone. It is of Jurassic age. It is coarse grained and

has interbeds of shale. We measured the dip and strike here which are as follows.

Strike: N 510 E

Dip: 700 SE

31

Fig 13. Showing Datta Santstone.

At the same point we observed Tridian sandstone. It is brownish red in color. It

also has some sedimentary features like ripple marks and cross bedding. We then moved

to another outcrop where we observed Calcareous Tuffa. It is deposit of Calcium

Carbonate in fresh water, it has structures called Spelithems.

DAY 3: Location 1

Here our first location was Dandot Village. Its coordinates are given below.

Coordinates are :

32

Lat: 320 40” 37.1’N

Long: 720 52” 13.2’E

Point 1

At point 1 we observed Tobra formation of brownish color and sandstone with

conglomerate. There was a contact between Warcha and Dandot which forms an

Anticlinal Structure.

Fig 14. Showing Tobra Formation.

Electrical Resistivity Surveying

Theory Resistivity is a physical property of materials related to how well current can pass

through the material. Most materials are insulators so the resistivity is normally

controlled by the water content of the subsurface material. Materials with a high water

content have a lower resistivity because the ions in the water allow current to flow more

easily.

33

Resistivity can be measured by passing a current into the ground and measuring

the potential difference. Separate pairs of electrodes need to be used for both functions

because of high contact resistances at the probes. A reversing square wave current source

this is applied to the ground to stop the build up ions at the probes and this also nullifies

the effect of telluric current. Telluric currents are naturally occurring currents that usually

flow parallel to the surface, when a reversing current is applied they add on when the

current is in the same direction and take off with the current is in the opposite direction,

this just shifts the measurements taken up or down so the telluric current effect can be

removed.

The purpose of electrical surveys is to determine the subsurface resistivity

distribution by making measurements on the ground surface. Resistivity method is good

for exploration of subsurface water and ore exploration, metallic ores, the data acquired

by resistivity survey is also used for identifying shallow structure like fault. From these

measurements, the true resistivity of the subsurface can be estimated. The ground

resistivity is related to various geological parameters such as the mineral and fluid

content, porosity and degree of water saturation in the rock. Electrical resistivity surveys

have been used for many decades in hydro geological, mining and geotechnical

investigations. More recently, it has been used for environmental surveys.

Determination of stratigraphy

Groundwater exploration

Mineral resource exploration

Sand, gravel and hard rock resource exploration

Locating fracture zones and voids

Mapping pollution plumes

Locating leakage from landfills

34

In an electrical resistivity exploration, electric current is applied to the ground surface

through two electrodes. Two or three additional electrodes are placed in the ground to

measure variations in the potential of the electrical field (voltage) that is set up within the

earth by the current electrodes.

There are two basic field procedures which are commonly used in electrical resistivity

1) Electrical traversing in which the electrode separation remains constant during the

survey.

2) Electrical sounding, in which the centre of the electrode spread is maintained at a fixed

location and the electrode spacing is increased in increments.

Electrical traversing is normally employed when a rapid survey of an area is desired.

It is particularly suited for prospecting for sand, gravel and ore deposits and for locating

fault zones or contacts between steeply dipping layers of earth materials

Electrical sounding is designed to provide information on the variation in subsurface

conditions with depth. Sounding is typically used to help determine the depth to the water

table, the thickness of sand, gravel and rock layers, and the actual value of electrical

resistivity versus depth.

Array Used In Survey:

Resistivity Configurations

In the field we have two current and two potential electrodes with different

spacing and we induce current in the earth with the help of current electrode and measure

potential difference by potential electrodes, potential will develop at right angle to current

line.

Current is known and measuring volt with the help of potential electrode and

measure resistivity, this depend on certain factors which type of array configuration is

used.

35

There are three important configurations

Wenner configuration

Schlumberger configuration

Dipole-dipole configuration

Wenner configuration

If the distance between AM, MN, NB is equal this configuration is called Wenner

configuration.

Dipole-dipole configuration:

In which current electrodes on one side and potential electrode on other side, and

distance between current and potential electrode are same this configuration is called

dipole-dipole configuration.

Figure 5.13:.Electrode arrays used to measure resistivity.

Schlumberger:

In field we are using Schlumberger configuration in which we move only current

electrode and fix potential electrodes.

Potential electrodes are kept fixed until measured voltage decreases to low values

as potential gradient in ground falls with increasing current electrode separation.

Then moved and process repeated.

36

Processing

On the whole the SAS 1000 / 4000 is equipped with a PC-compatible

microcomputer and controlled by four knobs (Figure-1). Each knob is mounted on a

hook, fixed in the instrument panel, and the motion of the knob is transferred

magnetically.

To turn on the SAS 1000 / 4000, press the two lower knobs towards each other as

indicated by the ON, OFF symbol on the instrument panel. A LED (Light Emitting

Diode) indicates that the instrument is starting, and after approximately 20 sec the start

menu comes up on the display.

For measurements utilizing only one channel (out of the four channels) it is often

easier to use the four connectors labelled C1, C2, Pl and P2. These connectors are

localized above the instrument display. In cases where more channels are needed, the

MULTI connector has to be used; The Cl, C2, Pl and P2 connectors are connected in

parallel to the corresponding pins in the MULTI connector. To connect more than one set

of potential electrodes, use the Multi Channel Adapter (optional accessory for the SAS

4000), Stainless steel potential electrodes are preferable, although ordinary steel

electrodes are acceptable,

37

Methodology

The instrument used was an ABEM Terrameter.

The instrument contains four operating knobs; using them we can change the

parameters according to our needs.

The measurement of resistivity done using four electrodes placed into the ground. 

The electrodes A & B are the current electrodes and the electrodes M & N are the

voltage electrodes.

The electrodes are simply metal stakes about 0.3 m long that are hammered

vertically into the ground. 

The electrodes are spaced apart according to an array at different locations as

described in the grid shown above.

The electrodes are connected to the instruments via cables.

A fixed value of current is current is selected and we turn on the instrument.

After a short interval of time we get the resistivity value.

DAY 4

Location 1

Our first station on fourth day was Katas Raj. Its latitudes and longitudes are

given below.

Lat: 320 43” 8.1’ N

Long: 720 57” 12.3’ E

Point 1

38

Here we observed calcareous tuffa. It is formed from the deposition of calcium

carbonate in fresh water. It is of very younger age i-e Holocene. It has white layers. Each

layer preserve important history. Its surface is very much weathered so called Karst

topography. It also has long elongated structures which are called Spelithems.

Fig 15. Showing Calcareous Tuffa.

Location 2

Lat: 320 44” 58’ N

Long : 720 57” 12.3’ E

Here we observed Rawalpindi Group. It is of Miocene age and has two members.

Murre Formation and Kamlial Formation. These two formations can be differentiated on

the base that Kamlial Formation has spheroidal weathering. Laminations are also presnt

in the rock and it can easily be scratched. Here we also took section measurement which

is as follows.

Table 5

39

S. No

Bed thickness Sorting Grain Size Structures Color

1 4 feet Well Sorted Coarse Joints Maroon2 6 feet Well Sorted Coarse Joints Redish3 3 feet Medium

SortedMedium Cross

BeddingBrownish

4 2 feet Well Sorted Fine Nill Brownish5 3 feet Poorly Sorted Coarse Nill Brwonish

Black6 3 feet Well Sorted Fine Nill Yellowish7 2 feet Well Sorted Fine Cross

BeddingGreenish Grey

8 6 feet Medium Sorted

Fine Cross Bedding

Yellowish

9 5 feet Poorly Sorted Fine-Medium

Nill Brownish

10 3 feet Poorly Sorted Medium Nill Brownish

40

CONCLUSION

Pakistan is full of beautiful mountain ranges like, Himalaya, Hindukush, and

Karakurm. There are many other ranges in Pakistan which are full of geological features.

Pakistan is the best place to study the geological structure, history and ages. The salt

range of Pakistan is good for studying the geological ages. Allah has blessed Pakistan

with a huge amount of geological structures and features. Salt range is also called the

“Museum of Geology” because here we can see everything related to geology and almost

all the geological features we use to study in our books are present in this region. This

field thus provided us with a great amount of knowledge and practical approach to

analyze and study various geological structures and features. As in this modern age the

geology has a great importance in exploration of oil and gas, one should know the

regional geology and the tectonic settings of the area.

In the western Salt Range, there is a significant angular unconformity above the

Cretaceous and there is angular unconformity (Surghar and Khisor Ranges) they overlie

Triassic/Jurassic rocks. The area contains active frontal thrust due to which we saw

repeating formation. We saw Cambrian formation that overlain Eocene formations. At

some part, salt range formation is also present which belongs to Precambrian age. This

shows that the area we visit was highly deformed. The Zaluch and Nammal sections have

excellent exposures of upper Permian geology in Pakistan.

The Chhidru Formation has been given the Early Dzhulfian to Late Dzhulfian age on the

bases of current studies and research on brachiopods. Paleoenvironmental study based on

brachiopods suggests inner sublittoral environment for the Chhidru Formation while

faunal dominancy in Zaluch section suggesting comparatively deeper environment of

deposition for Chhidru Formation. Brachiopods in Zaluch and Nammal sections show

almost same faunal details but the only variation observed is the fossil range and

population.

41

REFERENCES

A., Sajjad, A., Irshad and Khan, M., Irfan 2005. Structure and Stratigraphy of the

Paleozoic and Mesozoic Sequence in the Vicinity of Zaluch Nala, Western Salt Range,

Punjab Pakistan vol. 15 4-6.

Arshad, M., 2006 Site Management Plan Kallar Kahar Game Reserve 2, 5-10

Ahmad and Waseem, 2004 Taxonomic studies of Grasses of Salt Range of Pakistan 1-5

Ahmad, A., S., Hussain, M., Ashraf, M., and Ashraf, Yasin, M., Spatio-Temporal

Variations In Soil Characteristics In The Sub-Mountainous Himalayan Tract Of Pakistan

2.

Dan M. Baker, Robert J. Lillie, Robert S. Yeats, Gary D. Johnson, Yousuf , M., and

Sher,Hamid Development of the Himalayan frontal thrust zone: Salt Range, Pakistan 35-

42.

Ali H. Kazmi, H., Ali, and  Jan, Qasim, M., 1997 Geology and Tectonics of

Pakistan pg 130-131 187-190.