The Salt Range formation
The Salt Range is a hill system in the Punjab province of Pakistan, deriving its name from its extensive deposits of rock salt. The
range extends from the Jhelum River to the Indus, across the northern portion of the Punjab province. The Salt Range contains the
great mines of Mayo, Khewra, Warcha and Kalabagh, which yield vast supplies of salt. Coal of a medium quality is also found.

Sakaser and Tilla Jogian are the highest peaks of Salt Range.

Khabikki Lake and Uchhali Lake are lakes in the Salt Range.
The Salt Range forms the southern border of the hydrocarbon bearing Potwar basin in northern Pakistan, along the northwestern
margin of the Indo- Pakistani plate (Sameeni,2009). The Eocene rocks exposed in the Salt Range are divided from base to top into
Nammal Formation, Sakesar Formation and the Chorgali Formation respectively. The nomenclature of the Eocene succession in the
Salt Range as accepted by the Stratigraphic Committee ofPakistan (Fatmi, 1973) The term “Chorgali beds” of Pascoe (1920) has been
formalized as Chorgali Formation by the Stratigraphic Committee of Pakistan. The formation also represents the “Passage beds” of
Pinfold (1918) in the Attock area, “Bhadrar Beds” of Gee and Evans (In Davies and Pinfold 1937) in the Salt Range and “Lora
Formation” of Latif (1970a)in the Hazara area.
The Eocene rocks exposed in the Salt Range are mainly the limestones, marls, clays and shales and highly rich in well preserved
fossils. The fossil pelycepod were collected from Chorgali Formation locally known as Bhadrar Beds. The present collection was
carried out from the basal beds of Chorgali Formation which consists of mainly soft marl and argillaceous limestone, located about
one kilometer east to south-east of the Nurpur village, Salt Range
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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.
9
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.
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.
10
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.
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
Pleistocene and late Kalabagh Conglomerates
pliocene
(naushahra sandstone and
conglomerates)
LITHOLOGY
Brown and gray
conglomerates with
sandstone and clay
interbeds
Major Unconformity
Pliocene &
late Miocene
SOAN
SIWALIK
Late Miocene
Dhok Pathan
GROUP
Nagri
light coloured sandstone &
conglomerate light red and gray
clays
Red-brown clays with gray
sandstone; conglomeratic near
Indus
Greenish -gray sandstone and
clays; Conglomeratic near Indus
Bright red clays with
sandstone
Middle
Miocene
Chinji
Massive red and brown
sandstones, dark red clays
Kamlial
Early Miocene
Rawalpindi
GROUP
Muree
Massive sandstones, dark red and
purplish clay-shales; basal
conglomerate
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Major Unconformity
Chor Gali
(Bhadar Beds)
Early
Chharat
Group
Sakesar
Eocene
Nammal
Patala
Makarwal
Paleocene
Group
Lockhart
(Khairabad)
Hangu
(dhak pass)
Early
cretaceous
Major Unconformity
Lumshiwal
Surghar
group
Early
cretaceous &
late Jurassic
Chichali
(belemnite beds)
Middle Jurassic
Baroch
Group
Unconformity
Samana suk
(baroch
limestones)
Shinawari
Early
Jurassic
Data
(variegated beds)
Late
Triassic
Middle
Triassic
Unconformity
Kingriali
(kingriali
dolomite)
Musakhel
Tredian
Group
(kingriali
sandstone)
Olive-green shales with
bedded Limestones
Massive and nodular
limestones, with marls;
chert in upper part
Light gray calcareous
shales and limestone
Green shales with coal seam
in east; thin
limestones
Gray, semi-nodular and
marly limestones
Impure limestones,
sandstones, and shales, often
carbonaceous
Light-colored sandstones
with carbonaceous bands
Dark green to black
glauconitic shales
sandstones
and
Gray and purple bedded
limestones
with
shale
interbeds
Alternating limestone, shale
and siltstone;
sandstone at top
Sandstones with
limestones,
carbonaceous
shales and lateritic zones
Massive light colored
dolomite and dolomitic
limestones, with sandstones
Massive gray and purplish
sandstone, with thin
carbonaceous bands
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Mianwali
(ceratite beds)
Early
Triassic
Late
Permian
Paraconformity
Chhidru
(Up. Productus)
Wargal
(Middle
Productus)
Amb
(Lower
Productus)
Zaluch
Group
Sardhai
(Lavender clays)
Early
Permian
Limestone, marl and
calcareous sandstone
Massive gray limestones;
occasional thin
carbonaceous bands
Calcareous sandstone and
impure limestone;
carbonaceous shale
interbeds
Dark purple and lavender
clays with subordinate
sandstones
Nilawahan
Group
Warchha
(Speckled
sandstones)
Dandot
(conularia beds)
Tobra
(talchir
conglomerates)
Jhelum
group
Middle
&
Early(?)
Cambrian
Olive-green and gray shales
with thin limestones and
sandstones
Jhelum
Group
Major Unconformity
Baghanwala( salt
pseudomorph
beds)
Jutana
(magnesian
sandstone)
Kussak
(neobolus shales)
Khewra
(purple
sandstones)
Red and light colored
sandstones and grits in part
arkosic; calys interbeds
Olive-green and gray
sandstones and shales,
occasionally carbonaceous
Conglomeratic sandstones
and shales, boulders mainly
igneous or metamorphic
Blood-red shales and
flaggy sandstones;
pseudomorphs
with
salt
Massive
light-colored
dolomite
and
dolomitic
sandstones; subordinate
shales
Gray and purplish shales and
glauconitic sandstones; pebblebed at base
Massive maroon finetextured 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.
16
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.
17
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),
formation” by Teichert is now called as Amb formation by SCP.
“Amb
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
formation is Shallow marine to palludal.
of
this
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.
20
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.
21
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.
Billian wala 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
23
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, welldefined 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.
30
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:
3
1
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.