Salt Range Field Report

STRATIGRAPHIC STUDY OF SALT RANGE
Submitted
By
MUHAMMAD ASLAM KHAN
BS Geology (Batch-1)
…………………………………………………………………………………………………………..
Field Report Submitted To Muhammad Awais Lecturer Geology
Department, University of Swabi

Introduction of Salt Range
The Salt Range contains the most important geologic and paleontological localities in
Pakistan and is one of the outstanding field areas in the entire world. In fact, it represents an open
book of geology where various richly fossiliferous stratified rocks are very well exposed due to
lack of vegetation. It is also called as museum of geology and paleontology. The Salt Range forms
the southern border of the hydrocarbon-bearing Potowar Basin in northern Pakistan, along the
northwestern margin of the Indo-Pakistani Plate (Fig. 1).
Figure 1: Map of the Salt Range, Pakistan (after E.H. PASCOE, 1919).
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 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.

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 (Main Boundary Thrust).
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:
 Eastern Salt Range
 Central Salt Range
 Western 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 altitude of 1422m at Sakesar.
Similarly 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.
Field Visit
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 lithology of the various formation exposed in the above said Gorges. We also
observed a very important mineral deposit e.g. Khewra Salt mine.

EASTERN SALT RANGE
The different areas that we visited in eastern salt range are marked in the following satellite
image on the basis of GPS data taken in the field.
Figure 2: Satellite image of the study areas (stations) that were visited in Eastern Salt Range.
Station # 1
At station 1, there was Sakesar Limestone and location was Katas. This formation is the
second member of the Chharat Group. Lithology of this formation is limestone which is cream to
light gray in color, nodular, and massive in the upper part and also highly fossiliferous. Chert
nodules are present in Sakesar Limestone (fig. 3). Mostly forams are present in this formation.
Mollusks and Echinoids are also present, due to the presence of these fossils, the age assigned to
this formation is Early Eocene. Its environment of deposition is shallow marine. The upper contact
is with Chorgali Formation and this contact is conformable (fig. 4). The lower contact is with
Nammal Formation and it is also conformable. Chorgali is the last member of Chharat group and
is of Early Eocene age. Main lithology of Chorgali is olive green shale with bedded limestone (fig.
5). According to the GPS data (32°43.482' N and 72°57.451' E) satellite image of the study area
(fig. 2) and elevation is 690 meter.

Figure 3: Chert nodules in Sakesar limestone (coin is for scale).
Figure 4: Conformable contact between Chorgali formation and Sakesar Limestone, camera
facing south-east (geological hammer is for scale).

Figure 5: Chorgali Formation with shale and limestone beds, camera facing north-west
(geological hammer is for scale).
Station # 2
At station 2, there was Tobra Conglomerate. This formation is the first member of the
Nilawahan group. Nilawahan group represent the Lower Permian strata of the Salt range. Main
lithology of this formation is conglomerate (fig. 6), 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. Environment of deposition of this formation is Glacio-Fluvial
and Fluvial environment. Various fossils reported from this formation are pollens, spores etc. Age
assigned to this formation is Lower Permian. The upper contact of this formation is with Dandot
Formation and conformable. The lower contact of this formation in Zaluch Nala is with Lei
conglomerate which is an unconformable contact. On basis of GPS data (32°40.591' N and
72°58.252' E) satellite image of the study area (fig. 2) and elevation is 677 meter.

Figure 6: Tobra Conglomerate, camera facing east (geological hammer is for scale).
Station # 3
At station 3, there was Baghanwala formation. This formation is the last member of Jehlum
group. Main lithology of this formation is blood-red shales and flaggy sandstones; with salt
pseudomorphs (fig. 7). Sandstone is thick bedded while shale is thin bedded. The upper contact of
the Baghanwala Formation with the overlying Tobra Formation is unconformable which can be
easily seen on Khewra-Choa Saidan Shah road (fig. 8), whereas the lower contact with the Jutana
Formation is conformable. Environment of deposition of Baghanwala Formation is Lagoonal
environment. According to GPS data (32°40.089' N and 72°58.931' E) satellite image of the study
area (fig. 2) and elevation is 652 meter.
Figure 7: Salt pseudomorphs in Baghanwala Formation (coin is for scale).

Figure 8: Unconformable contact between Tobra Conglomerate and Baghanwala Formation,
camera facing north (geological hammer is for scale).
Station # 4
At station 4, there was contact between Khewra Sandstone and Salt Range Formation in
Khewra Gorge which is a thrust fault (fig. 9). Khewra Sandstone is the first member of Jehlum
group and is of Early Cambrian in age. Main lithology of Khewra Sandstone is Shale and purple
sandstones. Environment of deposition of Khewra Sandstone is deltaic environment. There were
climbing ripple marks in Khewra Sandstone (fig. 10). While Salt Range Formation is of Pre-
Cambrian age and is also called as Punjab Saline Series. Main lithology of this formation is red
gypseous marl with rock salt, gypsum-dolomite above; occasional oil shale. Marl is bright reddish
in color. Environment of deposition of Salt Range Formation is evaporitic environment. According
to GPS data (32°40.075' N and 73°00.287' E) satellite image of the study area (fig. 2).

Figure 9: Thrust Fault between Khewra Sandstone and Salt Range Formation, camera facing
north-east direction.
Figure 10: Climbing ripple marks in Khewra Sandstone, camera facing south (GPS is for scale).

Station # 5
At station 5, there was contact between Khewra Sandstone and Kussak Formation (fig. 11)
in Khewra Gorge. Kussak Formation is of Early Middle Cambrian and is the second member of
Jehlum group. Main lithology of Kussak Formation is gray-purplish shales and glauconitic
sandstones. Lower contact with underlying Khewra Sandstone is conformable and upper contact
with overlying Jutana Formation is also conformable. Its environment of deposition is marine
environment. On the basis of GPS data (32°40.185' N and 73°00.227' E) satellite image of the
study area (fig. 2) and elevation is 369 meter.
Figure 11: Conformable contact between Khewra Sandstone and Kussak Formation (man is for
scale).
Station # 6
At station 6, there was Khewra Trap in Khewra Gorge which is the product of only igneous
activity in the entire Salt range (fig. 12). Khewra Trap is also known as “Khewrite”. It is a thin
flow of an ultrapotassic rock (silica-under-saturated rock) and is purple reddish, brown, orange to
buff, rarely dark green 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. According to GPS data (32°40.016' N and 73°00.291' E) satellite image of the study area
(fig. 2) and elevation is 340 meter.

Figure 12: Type locality of Khewra Trap, camera facing south-east (man is for scale).
Western Salt Range
Zaluch Nala
The different areas that we visited in Zaluch Nala of the western salt range are marked in
the following satellite image on the basis of GPS data taken in the field.
Figure 13: Satellite image of the study areas (stations) that were visited in Zaluch Nala.

Station # 1
At station 1, there was Tobra Conglomerate in Zaluch Nala. This formation is the first
member of the Nilawahan group. Nilawahan group represent the Lower Permian strata of the Salt
range. Main lithology of this formation is conglomerate (fig. 14), 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. Environment of deposition of this formation is
Glacio-Fluvial and Fluvial environment. The upper contact of this formation is with Dandot
formation but in Zaluch Nala, Dandot formation is missing so the upper contact is unconformable.
The lower contact of this formation in Zaluch Nala is with Lei conglomerate which is an
unconformable contact. According to GPS data (32°46.900' N and 71°38.359' E) satellite image
of the study area (fig. 13) and elevation is 270 meter.
Figure 14: Tobra Conglomerate of Zaluch Nala, camera facing north (coin is for scale).
Station # 2
At station 1, there was Warchha Sandstone (fig. 15) in Zaluch Nala. The second member
of this group i.e. Dandot formation is missing in the Zaluch Nala. Warchha Sandstone is of Early
Permian and is the third member of the Nilawahan group. Main lithology of this formation is

sandstone which is medium to coarse grained and mostly thick bedded and massive. Sandstone is
of red to maroon and light in color. The sandstone is arkosic. The formation is locally speckled
which caused the previous workers to call it as "Speckled sandstone". Cross bedding in Warchha
Sandstone (fig. 16). Environment of deposition of this formation is fluvial (flood plain). The upper
contact of this formation is with overlying Sardhai Formation which is conformable. The lower
contact of this formation is unconformable in Zaluch Nala. On the basis of GPS data (32°46.892'
N and 71°38.261' E) satellite image of the study area (fig. 13) and elevation is 268 meter.
Figure 15: Coarse grained Warchha Sandstone, camera facing north-east (coin is for scale).
Figure 16: Cross bedding in Warchha Sandstone, camera facing north (GPS is for scale).

Station # 3
At station 3, there was Amb Formation in Zaluch Nala. Amb Formation is the first member
of Zaluch Group and is of Late Permian age. This formation consists of thin to medium bedded
sandstone and limestone (fig. 17). Environment of deposition of this formation is shallow marine
to paludal (marsh - dominated by herbs). Thin beds of shale are also present. Upper contact with
Wargal limestone is conformable and the lower contact with Sardhai formation is also
conformable. According to GPS data (32°46'52.41" N and 71°38'42.95" E) satellite image of the
study area (fig. 13).
Figure 17: Sandstone of Amb Formation, camera facing south-west (man is for scale).
Station # 4
At station 4, there was contact between Amb Formation and Sardhai Formation in Zaluch
Nala (fig. 18). Sardhai Formation is the fourth or last member of Nilawahan Group and is of Early
Permian. Main lithology of Sardhai Formation is dark purple and lavender clays with subordinate
sandstones. Environment of deposition of this formation is fluvial dominated delta (fluvial-
marine). Upper contact of this formation is with overlying Amb formation which is conformable
contact. Lower contact of this formation with Warchha Sandstone is also conformable. According
to GPS data (32°46'59.62" N, 71°38'49.13" E) satellite image of the study area (fig. 13).

Figure 18: Picture showing Sardhai clays, camera facing north.
Station # 5
At station 5, there was Datta Formation in Zaluch Nala. Datta Formation is the first member
of Baroch Group and is of Early Jurassic age. Main lithology of Datta formation is Sandstones
(fig. 19) with limestones and carbonaceous shales. Environment of deposition of this formation is
very shallow marine to deltaic and alluvial plains. Upper contact of this formation with overlying
Shinawari Formation is gradational and conformable. Lower contact with underlying Kingriali
Formation is unconformable. According to GPS data (32°47.249' N and 71°39.072' E) satellite
image of the study area (fig. 13) and elevation is 418 meter.
Figure 19: Datta Sandstone, camera facing south (man is for scale).

Nammal Gorge
The different areas that we visited in Nammal Gorge of the western salt range are marked
in the satellite image on the basis of GPS data taken in the field.
Figure 20: Satellite image of the study areas (stations) that were visited in Nammal Gorge.
Station # 6
At station 6, there was contact between Sardhai Clays and Warchha Sandstone (fig. 21).
Sardhai Formation is including dark purple and lavender clays with subordinate sandstones while
Warchha Sandstone consist of red and light colored sandstones (arkosic). According to GPS data
(32°38.325' N, 71°47.581' E) satellite image of the study area (fig. 20) and elevation is 335 meter.

Figure 21: Contact between Sardhai clays and Warchha Sandstone, camera facing north (man is
for scale).
Station # 7
At station 7, there was Chhidru Limestone in the Nammal Gorge. Chhidru Limestone is
the third member or last member of Zaluch Group and is of Late Permian age. Main lithology of
this formation is limestone, marl and calcareous sandstone. Environment of deposition of this
formation is shallow marine, littoral to paludal. The lower contact of this formation with Wargal
limestone is conformable. The upper contact with Mianwali formation is not conformable (fig.
22). The boundary between Paleozoic Era and Mesozoic Era is called Permo-Triassic boundary. It
is passage of Marine Permian to Marine Triassic. 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 which is a Paraconformity. According to GPS data (32°39.279' N
and 71°47.684' E) satellite image of the study area (fig. 20) and elevation is 273 meter.

Figure 22: Permo-Triassic boundary between Chhidru Limestone and Mianwali Formation,
camera facing south-east (man is for scale).
Reference: Stratigraphy of Pakistan 2009 by S.M Ibrahim Shah
THE END

Salt Range Field Report

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