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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.
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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
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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.