Field report of swabi area, department of geology university of peshawer

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FIELD REPORT OF SWABI FIELD TRIP
SUPERVISORS:
• MR.NOWRAD ALI
• MR.NAVEED ANJUM
SUBMITTED TO:
• MR.NAVEED ANJUM
SUBMITTED BY:
• MUHAMMAD SULIMAN
BS GEOLOGY PART: 1st
UOP PESHAWAR

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CONTENTS
• ABSTRACT
• INTRODUCTION
• CHAPTERS
a. SIDEMENTARY ROCKS
b. METAMORPHIC ROCKS
c. IGNEOUS ROCKS
d. GEOLOGIC STRUCTURES AND FEATURES
e. REFERENCES

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ABSTRACT
Our field trip to district Swabi was arranged on
08/04/2019. Swabi is located within Peshawar basin.
An almost complete Paleozoic sequence of
sedimentary rocks is exposed in the ranges of fringing
the Peshawar basin. The Precambrian-Cambrian
Tanawal formation forms the base of the sequence
and is overlain unconformably by the Ambar
formation (Cambrian). The Misri Banda Quartzite
unconformably overlies the Ambar formation and
contains Cruziana ichnofossils which indicate an early
to middle Ordovician age. The limestone at the base
of panjpir formation contains silurieus zone
conodonts and unconformably the Misri Banda
formation. The early to late Devonian Nowshera
formation overlies the Panjpir and contains a reef
facies first recognized by Stauffer in 1968. The
youngest recognized Paleozoic unite is the Jafar
Kandao formation from which carboniferous
conodonts have been obtained. The section outlined
above have possible correlatives in the Khyber and
Hazara regions, but differ dramatically from Paleozoic
sequence of the salt Range to the south. The tectonic
setting of the area is transitional between a

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sedimentary fold-thrust belt the south and a
Metamorphic terrane to the north.
Figure 1-Swabi area(Map) in Peshawar basin study area //photo from google.

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INTRODUCTION
Our 2nd geological trip was arranged on
08/04/2019 to the area of Swabi district along
with other areas with in Peshawar basin. The trip
was organized under the supervision of
MR.NAVEED ANJUM and MR.NOWRAD.
We left the department at 9:00 am sharply, and
started our journey through Motorway from
Peshawar to Swabi passing through Mardan
district.
The area is located within the Peshawar Basin.
The Peshawar basin is overlain by lacustrine
sediments of quaternary age, having maximum
thickness of 300 meters.
It is imagined that Peshawar basin was bounded
by mountains from all three sides, except at
south, the waters were flowing in from south,
forming a lake environment, due to uplifting of

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Attock-Cherat range, the basin came into
existence.
The Peshawar basin is bounded on the east by
Gandghar range and river Indus, on west by
Khyber range and on north by rocks of lower
Swat-Buner schistose group (Ambela granitic
complex). To the south of Peshawar basin is
Attock-cherat range.
There are six different formations along with
igneous rocks and intrusive structures.
Figure 2-Generalized map of eastern Peshawar basin showing study area (Pogue et al.1992)

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The 1st and oldest formation is the Tanawal
formation of Precambrian age containing mostly
quartzite of different types along with other low-
grade metamorphic rocks.
The 2nd formation which overlies the Tanawal
formation, is the Ambar formation of Cambrian
age mainly consisting of dolomite with little
limestone.
The 3rd formation overlying the Ambar formation
is Misri Banda quartzite of early to middle
Ordovician age composed mainly of quartzite.
The 4th formation is the Panjpir formation of
Silurian age which overlies the Misri Banda
formation mostly consisting of argillite and
phyllite with little limestone.
The 5th formation is the Nowshera formation
having early to late Devonian age, overlying the
Misri Banda formation mostly composed of
limestone, marble and other rocks.
The 6th and last formation is the Jafar Kandao
formation of carboniferous age overlying the

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Nowshera formation, consisting of argillite,
limestone etc.
The igneous rocks present over there were fine
grained Rhyolite, and tuff at Guhati village, and
Gabbros at Shewa Shahbaz Gahri. After
completing field we return back along Motorway
to Peshawar.
Figure 3-Paleozoic stratigrphic succession in the Peshawar Basin(after Pogue et al.,1992)

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CHAPTER.1
SEDIMENTARY ROCKS
Rocks formed from,
Sedimentary rocks are the product of the
erosion of existing rocks. Eroded material
accumulates as sediment, either in the sea or on
land, and is then buried, compacted and
cemented to produce sedimentary rock (a process
known as diagenesis).
TYPES:
a) Clastic or detrital
b) Non-Clastic/chemical S.R
c) Organic S.R
In case of sedimentary rocks, we observe only
limestone in field.
• Lime stone:
Limestone is a sedimentary rock consisting of
more than 50% calcium carbonate (calcite - CaCO
3). There are many different types of limestone
formed through a variety of processes. Limestone

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can be precipitated from water (non-clastic,
chemical or inorganic limestone), secreted by
marine organisms such as algae and coral
(biochemical limestone), or can form from the
shells of dead sea creatures (bioclastic limestone).
Some limestones form from the cementation of
sand and / or mud by calcite (clastic limestone),
and these often have the appearance of
sandstone or mudstone. As calcite is the principle
mineral component of limestone, it will fizz in
dilute hydrochloric acid.
At our 1st stop the supervisor lead us to an
outcrop, at the top of Panjpir formation that was
laid on road side was basically limestone
(Nowshera formation). In limestone fossils were
also present. That fossils were of marine type.
Crinoids are the dominant fossils of Nowshera
formation. Such fossils are given below…

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a)Gastropods: (more commonly known as snails
and slugs,
belong to a
large taxonomic
class of
invertebrates
within the
phylum
Mollusca,
called Gastropoda. This class comprises
snails and slugs from saltwater, from
freshwater, and from the land.
Figure 4-Gastropods fossils in Nowshera formation(limestone)//photo
by M.suliman and Meraj

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b)Crinoids: (are echinoderms related to starfish, sea
urchins, and
brittle stars.
Many crinoid
traits are like
other members
of their
phylum. Such
traits include
tube feet,
radial
symmetry, a
water vascular
system, and appendages in multiples of five
(pentameral).
c) Corals: (Corals are marine invertebrates within the
class Anthozoa
of the phylum
Cnidaria. They
typically live in
compact
colonies of
many identical
individual
polyps. Corals
species include
Figure 5-Crinoid fossils in Nowshera formation (limestone)//photo by
M.Suliman & Meraj
Figure 6-Corals in Nowshera formation(limestone)// photo by
M.Suliman & Meraj

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the important reef builders that inhabit tropical
oceans and secrete calcium carbonate to form a
hard skeleton.
d) Brachiopods: (are marine animals that, upon first
glance, look like clams. They are actually quite
different from clams in their anatomy, and they
are not closely
related to the
molluscs. They
are
lophophorates, and so are related to the Bryozoa
and Phoronida.
e) Ammonites: (are the extinct relatives of sea
creatures such as the modern Nautilus from Palau.
Ammonites lived during the periods of Earth
Figure 7-Brachipod fossils in Nowshera formation (limestone)// photo by
M. Suliman & Meraj

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history known
as the Jurassic
and
Cretaceous.
Together,
these
represent a
time interval
of about 140
million years.
The sample
of crinoidal limestone from the upper part of
Nowshera formation have yielded late Silurian
conodonts. This discovery provides the first
evidence for the rock of early and middle
Silurian age from Pakistan. On the basis of
previous and present conodonts finds, the age
of the Nowshera formation is regarded is
early to late Silurian.
Formation: Nowshera formation
Lithology: Crinoidal limestone
Age: Devonian
Color: Weathered surface; Brown grey
Figure 8-Ammonites in Nowshera formation// photo by M.Suliman &
Meraj

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Fresh surface; Light grey
Upper Contact: conformable contact with
overlying Jafar Kandao formation, contact is
placed at base of massive limestone.
Lower contact: with Panjpir formation.
Correlation: Nowshera formation resemble
Ghundai Sar “reef complex” of Khyber
Agency.
• DOLOMITIC LIMESTONE
Dolomite is a common rock-forming
mineral. It is a calcium magnesium
carbonate with a chemical composition of
CaMg(CO3)2. It is the primary component
of the sedimentary rock known as
dolostone and the metamorphic rock
known as dolomitic marble.
Limestone that contains some dolomite is
known as dolomitic limestone.

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At our 1st stop we also studied Marbalised
limestone. When limestone metamorphoses,
it converts
into marble.
The
dolomitic
limestone of
Nowshera
formation is
semi
metamorphosed to marble. Fewer fossils
were also present in marbalised limestone.
It constitute the youngest Paleozoic
sedimentary formation exposed between the
Nowshera and Swabi areas.
Formation: Nowshera formation
Lithology: Dolomitic Marbalised limestone
Age: Early to late Devonian
Color: Pinkish (due to Mn and Fe)
Figure 9-Marbalised limestone at Nowshera formation// photo by M.Suliman &
Meraj

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Texture: three different types of textures
I. Sugary: more course grained
II. Medium: medium grained
III. Fine: relatively fine grained
The rocks were
shining due to
more crystalline
form, therefore
they are used as
dimension
stone.
Upper contact:
unconformable
contact with
Jafar Kandao
formation. The
unconformity is marked by a discontinuous
conglomerate bed composed of pebble and
cobbles of argillite in quartzite-argillite matrix.
Lower contact: with panjpir formation.
Correlation: with Ghundai sar “reef complex”
ofKhyber area.
Figure 10-Marbalised limestone at Nowshera formation// photo by
M.Suliman & Meraj

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CHAPTER.2
MEHIC ROCKTAMORP
Metamorphism is the alteration of pre-existing
rocks in the solid state due to changes in temperature
and pressure. Under increasing temperature and / or
pressure existing minerals become unstable and
break down to form new minerals. In the case of
regional metamorphism, the rocks are subjected to
tectonic forces which provide the necessary
mechanisms for metamorphism. Products include
schist and slate. Contact metamorphism involves
metamorphosis through heating by an intruding
plutonic body. Hornfels is the result of this type of
metamorphism.
Metamorphic rocks are classified according to the
conditions under which they recrystallized, known as
their metamorphic facies. The key parameters in this
classification are index minerals which indicate
particular pressure / temperature conditions. These
minerals may only be present in small proportions,
and in many cases are difficult to recognize in hand
specimen. An alternative classification, useful in the
field or for hand specimens, is based upon the degree
of recrystallisation of the original minerals, and so

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grain size and the degree of foliation (see below) are
important. As metamorphism occurs in areas
undergoing deformation, look also for structures that
indicate deformation, such as folding (often shown as
crenulations or small crumpled folds), and small
fractures or faults.
• ARGILLITE
Argillite is highly indurated mudstone. Argillite
is commonly extremely deformed, fractured,
and veined. Although similar to shale, argillite is
generally have no fissiles, i.e. does not
preferentially break along closely spaced
bedding planes. It differs from slate in its lack of
foliation.
Formation: Panjpir formation
Color: argillite is grayish brown on fresh surface
and yellowish on weathered surface.
Age: Silurian

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Upper Contact: conformable contact with
overlying Nowshera formation, contact is placed
at base of massive limestone.
Lower contact: with Misri Banda quartzite
formation.
This formation was studied at 1st stop
• PHYLLITE
Phyllite is a metamorphic rock which forms
when slate is further metamorphosed until
very fine-grained white mica attains a
preferred orientation. Slate has fine clay
flakes which is oriented but with the phyllite it
has fine grained mica flakes that are oriented.
Its constituent platy minerals are larger than
those in slate but are not visible with naked
eye. Phyllites are said to have a texture called
Phyllitic sheen and are usually classified as
having formed through low-grade
metamorphism conditions through regional
metamorphism.
The protolith (or parent rock) for phyllite is
shale or Pelite, or slate, which in turn came
from a shale protolith. Its constituent platy

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minerals are larger than those in slate but are
not visible with the naked eye. Phyllites are
said to have a texture called "phyllitic sheen,"
and are usually classified as having formed
through low-grade metamorphic conditions
through regional metamorphism
metamorphic facies.
Phyllites are
usually black
to gray or
light
greenish
gray in color.
The foliation
is commonly
crinkled or
wavy in
appearance.
At our 1st stop of Swabi field trip we observe
phyllite at Panjpir formation. Our supervisor
told us that the outcrop on which we were
standing is phyllite, and composed of Mica
Figure 11-phyllite at Panjpir formation (highly jointed due to
stresses)// photo by M.Suliman & Meraj

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(muscovite and Biotite), Quartz and clay
minerals. Grains of mica were visible to the
naked eye. Similarly thin beds of limestone
were also present as a vein (when joint is
filled up with sediment). We saw phyllite rock
surface which were plater.
Formation:
Panjpir
formation
Lithology:
Phyllite
Age: Silurian
Texture: fine
grained
Color: black
to gray or
light greenish
gray in color. The foliation is commonly
crinkled or wavy in appearance.
Upper contact: conformable contact with
overlying Nowshera formation, contact is
placed at base of massive limestone
Lower contact: with Misri Banda quartzite
formation.
Figure 12-phyllite at Panjpir formation(highly jointed due to stresses)// photo
by M.Suliman & Meraj

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Correlation: Panjpir formation strongly
resembles the phyllite and interbedded
limestone sequence exposed below the
Ghundai Sar “reef complex” located at about
17 km northwest of Peshawar.

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CHAPTER.3
IGNEOUS ROCKS
Igneous rocks are formed when molten
material from within the Earth, called magma,
cools down and solidifies forming crystals.
They are thus characterised by an interlocking
crystalline texture.
Igneous rocks can be classified in various
ways:
1. Intrusive or extrusive. Intrusive (plutonic)
rocks form when magma solidifies within the
crust below the surface. It usually cools slowly
and produces large crystals. Extrusive
(volcanic) rocks form when magma erupts
onto the surface of the Earth as lava flows,
and usually cools quickly producing small
crystals. It can also erupt explosively as ash.
Sometimes molten lava remains for a long
time in its magma chamber, allowing crystals
of a specific mineral to form first, so that
when the whole rock is finally solid it contains

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these large crystals, called phenocrysts, set in
a ground mass of small crystals. A surface lava
sometimes cools very quickly, allowing no
time for crystals to grow; this results in the
formation of a glass.
2. Acidic, intermediate or basic, depending on
the amount of the elements of silica, SiO2,
they contain. Acidic rocks such as granite,
microgranite and olivine, pyroxene, feldspar
and/or quartz among others; they are also
rich in the metals magnesium and iron and
are often described as "mafic". The
intermediate rocks include diorite,
microdiorite and andesiterhyolite are rich in
silica and contain the minerals quartz,
feldspar and biotite among others. Basic rocks
such as gabbro, dolerite and basalt are poor in
silica and contain the minerals.

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SHEWA SHAHBAZ GAHRI GABBRO
GABBRO:
Gabbro is a dense, mafic intrusive rock. It
generally
occurs as
batholiths and
laccoliths and
is often found
along mid-
ocean ridges
or in ancient
mountains
composed of
compressed
and uplifted oceanic crust. Gabbro is the
plutonic equivalent of basalt.
Figure 13-fresh surface of gabbroic rock at Shewa Shehbaz Gari Gabbroic
complex of Peshawar plain alkaline igneous provence // photo by M.Suliman &
Meraj

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We study Shewa Shahbaz Gahri gabbroic complex
at 2nd stop. This gabbroic complex is the part of
Peshawar plain alkaline igneous province which
have intruded the Paleozoic sequence of
Peshawar basin.
Unite: Peshawar plain alkaline igneous province
Minerology: pyroxene(mostly) and plagioclase.
Color:
Melanocratic
(dark color due to
pyroxene) and
light grey due to
plagioclase.
Texture: course
grained (visible to
unaided eye). Figure 14-Weathered surface of gabbroic rock at Shewa Shehbaz Gari Gabbroic
complex of Peshawar plain alkaline igneous provence // photo by M.Suliman &
Meraj

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GUHATI RHYOLITE
Rhyolite is a felsic extrusive rock. Due to the high
silica content, rhyolite lava is very viscous. It flows
slowly, like tooth paste squeezed out of a tube,
and tends to pile up and form lava domes. If
rhyolite magma is gas rich it can erupt explosively,
forming a frothy solidified magma called pumice
(a very lightweight, light-colored, vesicular form
of rhyolite) along with ash deposits, and / or
ignimbrite. In certain situations extremely porous
rhyolite lava flows may develop. The extreme
porosity of such flows allows degassing and
subsequent collapse of the flow, forming obsidian
(dark colored volcanic glass). Rhyolite is the
volcanic equivalent of granite.

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We study Rhyolite at 3rd stop of our trip. The
rhyolitic complex is the part of Peshawar plain
alkaline igneous province which intrude the
Paleozoic
sequence of
Peshawar
basin.
The rocks were
powered (fault
gauge) and
Brecciated due
to tectonic
stresses. The
vesical, in rhyolite were filled up with Fe, Mn and
pyrite, called
amygdule.
Texture: very
fine grained,
cannot be seen
with out
microscope.
Porphyritic
texture was
Figure 15-fresh surface (bluish color) of Ghuhati Rhyolite, Peshawar plain alkaline
igneous provence // photo by M. suliman & Meraj
Figure 16-Sheared Rhyolite at Ghuhati (white color due fault gauge) // photo by M.
suliman & Meraj

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present which shows two stage of magma cooling.
Phenocrysts of that porphyritic texture were
consist of mostly
quartz and
feldspar.
Joints/fractures:
there were joints
in rhyolite which
were more than
one set.
Leaves like
appearance: The
rhyolites were having leaves like appearance or
structures, having black colors which are in fact
manganese accumulations during cooling of
Rhyolite from magma, called manganese
dendrites.
Color: white to light dark (not sheared)
Age: in Paleocene sequence.
Weathering: onion like layers were present in
Rhyolite showing expoliation weathering.
Composition: felsic(acidic)
Figure 17-Amagdules in Ghuhati rhyolite // photo by M. Suliman & Meraj

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Color: white- milky(sheared)
Feel: soupy touch
Appearance: powdery
Unite: Peshawar plain alkaline igneous province
INTRUSIVE STRUCTURE
DIKE:
Dikes are sheet intrusions that cut across layers,
or into an unlayered mass. Dikes usually follow
zones of weakness in the rocks they travel
through. Even if they came to lie horizontal, for
example by folding, as long as they cut host rock
strata they are still dikes. The rocks in dikes can be
both pegmatites (very coarse-grained) and aplites
(sugary fine-grained). Several dikes together can
form a dike swarm. – In scientific terms, a dike is a
relatively narrow tabular discordant body which

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propagates through rock perpendicular to the
least principal
stress.
We studied dike at
3rd stop in Ghuhati
rhyolite. The dike
which were
present in Ghuhati
rhyolite was
metamorphosed.
Mineralogy:
dolerite, which
were metamorphosed to meta dolerite (green
schist). Basic minerals in dolerite is chlorite,
epidote, feldspar and amphibole.
Color: weathered surface; brown greenish
Fresh surface; greenish grey.
Green color was because of the presence of
chlorite and epidote.
Figure 18-Intruded Dike (Meta Dolerite) at ghuhati Rhyolite// photo by M.
Suliman & Meraj u din

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REFFERENCES
• Sir Naveed Anjum Hints/lectures
• Sir Nowrad Hints
• Plummer book (physical geology)
• Tarbuck book (The earth)
• Wikipedia/rocks and minerals.