Day 1 in khewra gorge

Khewra Gorge and Chowa Road section Day 1
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Stratigraphic Sequence in Salt Range
Age Group Formation
Pleistocene Kalabagh Cong Mansehra S/St.
Conglomerate.
Pliocene, Late Miocene Siwalik Group Soan Formation
Dhok Pathan Formation
Nagri Formation
Chingi Formation
Early Miocene Rawalpindi Group Kamlial Formation
Murree Formation
MAJOR UNCONFORMITY
Early Eocene Charrat Group Chor Gali Formation
Sakesar Limestone
Nammal Formation
Makarwal Group Patala Formation
Lockhart Formation(Khanabad)
Hungu (Dhak Pass)
MAJOR UNCONFORMITY
Early Cretaceous (Early
Cretaceous and Late
Jurassic)
Surghar Group Lumshiwal Formation
Chichali Formation

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UNCONFORMITY
Middle Jurassic Baroch Group
Samanasuk(Baroch Limestone)
Shinawari Formation
Datta Formation (Variegated
beds)
UNCONFORMITY
Late Triassic Musakhel Group Kingrali (Kingrali Dolomite)
Tradian Formation
Mianwali Formation
PARACONFORMITY
Late Permian Zaluch Group Chiddru Formation (Upper
Productus)
Wargal Limestone (Middle
Productus)
Amb Formation (Lower
Productus)
Early Permian Nilawahan Group Sardhai Formation
Warchha Formation
Dondot Formation
Tobra Formation
Major UNCONFORMITY

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On day one, we went to the Khewra Gorge located in Eastern Salt Range. We observed different
formations. They are explained below
Salt Range Formation:
Synonym: Wynne (1878) named and described the formation as ‘Saline Series’. Gee (1945)
called the same unit as ‘Punjab Saline Series’. The present name, the Salt Range Formation has
been given by Asrarullah (1967).
Type Locality: Punjab, Khewra Gorge in the eastern Salt Range has been designated as its
type locality.
Age:The age of Salt Range Formation is late Precambrian or early Cambrian.
Lithology: The lower part of the Salt Range Formation is composed ofred-coloured gypseous
marl with thick seems of salt while the beds ofgypsum, dolomite, greenish clay and low grade
Middle and Early
Cambrian
Jehlum Group Baghanwala Formation (Salt
Pseudomorph Beds)
Jutana Formation (Magnesium
Sandstone)
Kussak Formation (Glauconitic
Sandstone)
Khewra Sandstone (Purple
Sandstone)
Pre Cambrian Salt Range Formation (Saline
Series)

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oil shale are the constituents of the upper part. A highly weathered igneous body knownas
“Khewra Trap” has been reported from the upper part of the formation. It consists of highly
decomposed radiating needles of a light-coloured mineral, probably pyroxene. The red-
coloured marl consists chiefly of clay, gypsum and dolomite with occasional grains and crystals
of quartz of variable size. Thick-bedded salt shows various shades of pink colour and well-
developed laminations and colour bandings upto a metre thick. The gypsum is white to grey in
colour. It is about 45m thick, massive and is associated with bluish grey, clayey gypsum. The
dolomite is usually light grey in colour and flaggy.
It has three members:
1. Sahwal Marl Member.
2. Bhandar Kas Gypsum Member.
3. Billianwala Salt Member.
Fossils:It is devoid of fossils.
Contacts:Its upper contact is with Khewra Sandstone which is normal and conformable and
lower contact with metamorphic rocks of Precambrian age.

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Fig .1 Gypsum beds of Salt Range Formation in Khewra gorge.
2. Khewra Sandstone:
Synonym: The name was originally proposed by Noetling (1894) as ‘Khewra Group’. Prior to
that Wynne (1878) called the formation “Purple Sandstone Series” and this name was
continued until recently when the name of the formation was formalized as “Khewra
Sandstone” by the Stratigraphic Committee of Pakistan.
Type Locality: The type locality is in Khewra Gorge near Khewra Town, Salt Range.
Age: The age of Khewra Sandstone is early Cambrian.
Lithology: The formation consists predominantly of purple to brown and yellowish brown
fine-grained sandstone. The lowermost part of the formation is red flaggy shale. The sandstone
is mostly thick bedded to massive. The Khewra Sandstone is widely distributed throughout the
Salt Range.

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Fossils:The formation contains only a few trace fossils in the Salt Range which have been
interpreted as trilobites.
Contacts:Upper contact is with Kussak Formation which is gradational and lower contact with
Salt Range Formation.
Fig 2.Purple sandstone with honey comb weathering in Khewra Sandstone.
3.Kussak Formation:
Synonym: Wynne (1878) applied the name ‘Obulus beds’ or ‘Siphonotreta beds’ to a
predominantly greenish grey, glauconitic, micaceous sandstone and siltstone. Waagen (1895)
used the name ‘Neobolus beds’ for the same unit. Noetling (1894) proposed the name ‘Kussak
Group’ and finally the Stratigraphic Committee of Pakistan named the Formation as “Kussak
Formation”.
Type Locality: The type locality lies near the Kussak Fort in the eastern part of the Salt Range.
Age:The age of the formation is either late early or early middle Cambrian.

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Lithology:The formation is composed of greenish-grey, gluconitic, micaceous sandstone,
greenish-grey siltstone, interbedded with light grey dolomite and some oolitic, arenaceous
dolomite. Numerous layers of intraformatinal conglomerate are present. Pink gypsum lenses
are present near the top. The general lithology throughout the formation is uniform. However,
thickness vary at different places.
Fossils:The formation is fossiliferous and has yielded the following fauna: Neoboluswarthi,
Bolsfordla granulate, Lingulellawanniecki, Redlichtanoetlingi.
Contacts: Upper contact is with Jutana Formation which is conformable and lower contact
with Khewra Sandstone which is gradational.
Fig 3. Shale and micaceous silt stone of Kussak Formation.

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4. Jutana Formation
Synonym: Fleming (1853) named this unit “Magnesian sandstone”. Noetling (1894) described
it as ‘Jutana Stage’. The Stratigraphic Committee of Pakistan formalized the name as “Jutana
Formation”.
Type Locality: The type locality lies near Jutana Village in the eastern Salt Range.
Age: It is early middle Cambrian or late early Cambrian.
Lithology:At the type locality the lower part of the formation consists of light green, hard
massive, partly sandy dolomite and the upper part is composed of light green to dirty white
massive dolomite. In the upper part, brecciated dolomite is also present with matrix and
fragments consisting of same rock.
Fossils:It contains Lingulellafushi, Botsfordia granulate, Redilchianoetlingi,
Pseudothecasubrugosa.
Contact:The formation is conformably underlain by the Kussak Formation and conformably
overlain by the Baghanwala Formation.
Fig 4.Massive dolomite of Jutana Formation.

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5. Baghanwala Formation:
Synonym: The name Baghanwala Formation is now given to the rocks of the ‘Pseudomorph
Salt Crystal Zone’ of the Wynne (1878) and the ‘Baghanwala Group’ of Noetling (1894). Holland
(1926) called these beds “Salt Pseudomorph be ds” and Pascoe (1959) named them
“Baghanwala Stage”.
Type Locality:It is near Baghanwala Village in the Eastern Salt Range.
Age: Early middle Cambrian
Lithology: The formation is composed of red shale and clay, alternating with flaggy sandstone.
The flaggy sandstone exhibits several colours including pink grey or blue green, especially in the
lower half of the formation.
Fossils:Devoid of fossils.
Contact:The contact of the Baghanwala Formation with the overlying Tobra Formation is
unconformable, whereas the lower contact with the Jutana Formation is conformable.

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Fig 5.Flaggy sandstone beds and shales in Baghanwala Formation.
6. Tobra Formation:
Synonym: It was previously known in the literature as “Talchir Boulder Bed” or “Talchir Stage”
of Gee and “Salt Range Boulder Bed” of Teichert (1967).
Type Locality:The type locality is located near Tobra Village in the eastern Salt Range.
Age: Early Permian
Lithology:The Tobra Formation depicts a very mixed lithology in which the following three
facies are recognized
1. Tilliticfacies exposed in the eastern Salt Range. This rock unit grades into marine
sandstone containing Eurydesma and Conularia fauna
2. Freshwater facies with few or no boulders. It is an alternating facies of siltstone and
shale containing spore flora.
3. A complex facies of diamictite, sandstone and boulder bed.
In the eastern Salt Range the Tobra Formation exhibits true trillite; the rock unit is composed of
boulders of granite with fragments of quartz, feldspar, magnetite, garnet, clay stone, siltstone,
quartzite, bituminous shale and gneiss. The matrix of the conglomerate bed is generally clayey,
sandy and at some places calcareous.
Fossils:Pollens and spores, Punctatisporites, Leiotriletes, Protohaploxypinus, and
Striatopodocarpites.
Contact:Upper contact with Dandot Formation which is gradational lower contact with
Cambrian rocks(Baghanwala Sandstone) which is disconformable.

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Fig 7.Tilaticfaciesof Tobra Formation.
7. Dandot Formation:
Synonym: The name Dandot Formation is formalized after the ‘Dandot Group’ of Noetling
(1901) and includes the “Olive Series”, ‘ Eurydesma beds’ of Wynne (1878) and the ‘Speckled
sandstone’ of Waagen (1879).
Type Locality: The type locality is near Dandot Village, eastern Salt Range.
Age:Early Permian.
Lithology:The lithology at the type locality consists of light grey to olive green yellowish
sandstone with occasional thin pebbly beds and subordinate dark grey and greenish splintery
shale.
Fossils: The Dandot Formation is fossiliferrous and the basal part in the eastern Salt Range has
yielded brachiopods including Discina species, Martiniopsis species and Chonetes species.
Contact:The formation has a gradational contact with the underlying Tobra Formation and is
terminated in sharp but conformable contact with the overlying Warchha Sandstone.

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Fig 8.shales and pebbly beds of sandstone in Dandot Formation.
8. Patala Formation:
Synonym: The term Patala Formation was formalized by the Stratigraphic Committee of
Pakistan for the “Patala Shale” of Davies and Pinfold (1937) and its usage was extended to other
parts of the Kohat-Potwar and Hazara areas.
Type Locality: The section is exposed in Patala Nala in the Salt Range.
Age:Late Paleocene
Lithology:The Formation consists of shale and marl with subordinate limestone and
sandstone. The shale is dark greenish grey, selenite bearing, in place carbonaceous and
calcareous, and also contains marcasite nodules. The limestone is white to light grey with
nodules. It occurs as interbeds. Subordinate interbeds of yellowish brown and calcareous
sandstone are present in the upper part. Coal seams of economic value are present locally.

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Fossils:Forams, molluses and ostracodes. Actinosiphontibetica, Assilinadandotica,
Discicyclineranikotensis, Lockhartiaconditi, Nummulitesgloblus, Globigerina linaperta.
Contact:Upper contact conformable and transitional with Namal Formation and lower contact
conformable with Lockhart Limestone.
Fig 9.Shale , and fire clays of Patala Formation.
9. Namal Formation:
Synonym: The term Nammal Formation has been formally accepted by the Stratigraphic
Committee of Pakistan for the “Nammal Limestone and Shale” of Gee (in Fermor, 1935) and
“Nammal Marl” of Danilehik and Shah (1967) occurring in the Salt and Trans Indus Ranges.
Type Locality: The section is exposed in the Nammal Gorge (lat. 32˚ 40˚ N :lon. 71˚ 07’ E) is
the type section.
Age:Early Eocene.

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Lithology: The formation, throughout its extent, comprises of shale, marl and limestone. In
the Salt Range, these rocks occur as alternations. The shale is grey to olive green, while the
limestone and marl are light grey to bluish grey. The limestone is argillaceous in places.
Fossils:Forams and moluscs, Assilinagranulosa, Discocyclinaranikotensis etc.
Contact:Upper contact transitional with sakeser limestone and lower contact with Patala
Formation which is transitional.
Fig 10.Nodular Limestone of Nammal Formation.
10. Sakesar Limestone:
Synonym:The term Sakesar Limestone was introduced by Gee for the most prominent Eocene
limestone unit in the Salt Range and Trasns-Indus Ranges.
Type Locality: Sakesar Peak in the Salt Range has been designated as the type locality.
Age: Early Eocene

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Lithology:The unit consists dominantly of limestone with subordinate marl. The limestone,
throughout its extent, is cream coloured to light grey, nodular, usually massive, with
considerable of chert in the upper part. The marl is cream coloured to light grey and forms a
persistent horizon near the top.
Fossils: Foramsmolluscs and echinoids, Assillinalaymeriei, Flosculineglobosa, Lockhartiaconditi
etc.
Contact:Upper contact conformable with Chorgali Formation and lower contact with Namal
Formation which is transitional.
Fig 11. Cherty nodules in massive limestone of Sakaser Limestone.

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Sedimentary Structures Observed in Eastern Salt Range:
Ripple Marks:
Ripple cross-laminae forms when deposition takes place during migration of current or
wave ripples. A series of cross-laminae are produced by superimposing migrating ripples.
The ripples form lateral to one another, such that the crests of vertically succeeding laminae
are out of phase and appear to be advancing upslope. This process results in cross-bedded
units that have the general appearance of waves in outcrop sections cut normal to the wave
crests. In sections with other orientations, the laminae may appear horizontal or trough-
shaped, depending upon the orientation and the shape of the ripples. Ripple cross-laminae
will always have a steeper dip downstream, and will always be perpendicular to paleoflow
meaning the orientation of the ripples will be in a direction that is ninety degrees to the
direction that current if flowing. Scientists suggest current drag, or the slowing of current
velocity, during deposition is believed to be responsible for ripple cross-laminae. In the field
we identify ripple marks in Khewra Sandstone.
Ripple Marks

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Cross Bedding:
In geology, the sedimentary structures known as cross-bedding refer to (near-) horizontal units
that are internally composed of inclined layers. This is a case in geology in which the original
depositional layering is tilted, and the tilting is not a result of post-depositional deformation.
Cross-beds or "sets" are the groups of inclined layers, and the inclined layers are known as cross
strata.
Cross bedding forms during deposition on the inclined surfaces of bedforms such as ripples and
dunes, and indicates that the depositional environment contained a flowing medium (typically
water or wind). Examples of these bedforms are ripples, dunes, anti-dunes, sand waves,
hummocks, bars, and delta slopes. In the field we observed cross bedding in Khewra Sandstone.
Cross Bedding

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Mud Cracks:
Mud cracks (also known as desiccation cracks or mud cracks) are sedimentary structures formed
as muddy sediment dries and contracts. Naturally forming mud cracks start as wet, muddy
sediments desiccates, causing contraction. A strain is developed because the top layer tries to
shrink while the material below stays the same size. When this strain becomes large enough,
channel cracks form in the desiccated surface material, relieving the strain. Individual cracks
spread and join up forming a polygonal, interconnected network. These cracks may later be filled
with sediment and form casts on the base of the overlying bed.
Mud Cracks
Honey Comb Weathering:

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Honeycomb weathering, also known as fretting, cavernous weathering, alveoli/alveolar
weathering, stone lattice, stone lace is a type of salt weathering common on coastal and semi-arid
granites, sandstones and limestone. Honeycomb weathering is not limited to natural settings and
can be seen to develop on buildings where a rate of development can be established. This rate
can be as fast as several centimeters in 100 years.
Cause
For honeycomb weathering to occur, a source of salt is needed because the basic mechanism for
this kind of weathering is salt heaving. Salt is deposited on the surface of the rock by saltwater
spray or by wind. Moisture must be present to allow for the salt to settle on the rocks so that as
the salt solution evaporates the salt begins to crystallize within the pore-spaces of the rock.
Porous rock is also needed so that there are pore-spaces for the salt to crystallize within. These
salt crystals pry apart the mineral grains, leaving them vulnerable to other forms of weathering. It
takes prolonged periods for this weathering to become visible, as the rock goes through cycles of
wetting and drying. We observed the honey comb weathering in Khewra Sandstone.
Honey comb Weathering

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Convolute Bedding:
Convolute bedding forms when complex folding and crumpling of beds or laminations occur.
This type of deformation is found in fine or silty sands, and is usually confined to one rock layer.
Convolutelaminations are found in flood plain, delta, point-bar, and intertidal-flat deposits.
They generally range in size from 3 to 25 cm, but there have been larger formations recorded as
several meters thick. We also observed it in Khewra sandstone.
Convolute Bedding

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Pseudomorph Salt Crystals:
In mineralogy, a pseudomorph is a mineral or mineral compound that appears in an atypical
form (crystal system), resulting from a substitution process in which the appearance and
dimensions remain constant, but the original mineral is replaced by another. The name literally
means "false form". We observed it in Baghanwala Formation.
Pseudomorph Salt Crytals
Load Casts:
Load casts or Sole marks are sedimentary structures found on the bases of certain strata that
indicate small-scale (usually on the order of centimeters) grooves or irregularities. This usually
occurs at the interface of two differing lithologies and/or grain sizes. They are commonly
preserved as casts of these indents on the bottom of the overlying bed (like flute casts). This is

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similar to casts and molds in fossil preservation. Occurring as they do only at the bottom of
beds.
Load Casts

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Hoddows Structures:
These are Hoddows structures which are found in Salt Range Formation.
Chopboard weathering:
We observed chopboard weathering in Jutana Dolomite.

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Stalactite
Burrows:

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Day 1 in khewra gorge

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