Geological Field Report on Sitakund Anticline

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Figure 0.1: In font of YPSA
Acknowledgment
Firstly, I want to thank Almighty Allah
for giving me a propitious opportunity
for performing a fieldwork trip to
Sitakund anticline hill tracts,
Chittagong.
This is an untold pleasure for me to
express my deep sense of gratitude to
our honorable teacher, Field Geology
Expert Muhammad Risalat Rafiq,
Assistant professor, Department of
Geology & Mining, University of
Barishal, for his sentient guidance,
lively support, throughout contribution
and discreet co-operation throughout
the field survey.
I also like to express my sense of
gratitude with great pleasure Md.
Abdullah Salman, Lecturer,
Department of Geology & Mining,
University of Barishal, for his
consistent guidance, valuable advice,
and proper instruction throughout the
field survey. His presence encouraged
us with thoughtful instructions and
suggestions.
It was conducted from 27th
December
2021 to 2nd
January 2022, which didn’t
only helps us to complete our field
smoothly and with great pleasure but
also resulted in the completion of this
result and kindly perspective provided
by the diversity of their viewpoint and
experience and their many thoughtful
suggestions they have been made along
the field have led to significant
improvements in my study.
I would like to offer the heartiest
gratitude and appreciation to our
Chairmen, Sukhen Goswami, Assistant
professor, Department of Geology &
Mining, the University of Barishal for
such kind of arrangement of the field
trip, Sitakund Anticline in Chittagong
district.
I would like to thanks immensely for the
quality of support rendered by YPSA
(Young Power in Social Action),
Sitakund branch for providing our
accommodation. YSPA was our Base
Camp.
I thank the chefs who cooked in a
timely. They ensured hygienic food
items for us.
Besides, I show gratitude to the
transport Saudia Paribahan and Pubali-
7 launch to assist us in case of
transportation.
I want to thank our classmates who
work hard for managing this field trip
and also others for supporting them.
I also want to thank local people and
local authorities who give us instruction
when we need it and safely.

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Executive Summary
The field report is based on all the
scientific facts and data found during
the brief field survey on the
Shahasradharara section, Barabkund
Hill section, and Chandranath Hill
Section in the Sitakund Anticline area in
Chittagong District. This field report
deals with the physiographic,
structural, stratigraphic, and
sedimentological. And geomorphic
characteristics of Sitakund Anticline
along with practical and economic
aspects.
The Sitakund Anticline is situated in the
southeast part of Bangladesh under
Chittagong District. It is above 75 km
long and 10 km wide and is one of the
westernmost structures of Chittagong
and the Chittagong Hill Tracts. The
Sitakund Anticline range act as a water
divide between Halda Valley and
Swandwip Channel.
Structurally, Sitakund Anticline is one of
the prominent structures of the eastern
folded belt of the Bengal Basin. The
Sitakund Anticline is trending in the
NNW-SSE direction. It is an asymmetric
fold and the western flank of the
anticline is faulted regionally, the
alignment of which runs parallel to the
NNW-SSE trending regional strike.
The Sitakund Anticline is completely
composed of sedimentary rock which
was deposited during the tertiary age in
the marginal marine environment. The
sedimentary beds are mainly composed
of sandstone and shale but at some
places, mudstone, and siltstone are also
found. So, the overall lithology of the
area can be described as the alteration
of sandstone and shale with a minor
presence of mudstone and siltstone at
different sites.
In our investigation, we got some
geomorphic features such as stream,
pool, riffle, rapid, waterfall, slump,
pothole, etc.
The report gives us the study of rock
samples collected from three
consecutive sections. They are the
Shahasradharara section, the
Barabkund Hill Section, and the
Chandranath Hill section. There are
some economical aspects and
importance of this area. It is anticipated
that there is a reservoir of gas and
petroleum in this area. Several gases
seepage that we have found in our
investigation are provides strong
evidence of it. Besides many hard rocks
are supplied from this area for
industrial and construction projects.
These areas also have the importance
of religious views.

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Table of Content
Content Page No.
Acknowledgment 01
Executive Summary 02
List of figures 05
List of tables 07
List of Maps 08
Chapter 01: Introduction 09-14
1.1 Background 10
1.2 Scope of Study 10
1.3 Objectives 11
1.4 Previous work 12
1.5 Study area 13
Chapter 02: Physiography 15-20
2.1 Topography 16
2.2 Drainage pattern 18
2.3 Climatology 19
2.4 Population & Culture 20
Chapter 03: Geological Setup 21-26
3.1 Tectonics 22
3.2 Geomorphology 23
3.3 Structural Geology 25
3.4 Petrology 26
Chapter 04: Methodology 27-29
4.1 Method of Study 28
4.2 Lab Investigation 29
4.3 Equipment 29
Chapter 05: Description of Individual Section 30-58
5.1 Shahasradhara Section 31-39
 Measuring the height of the waterfall 34
5.2 Barabkund Hill Section 40-50
 Gas Seepage 41
5.3 Chandranath Hill Section 51-58
Chapter 06: Structure 59-64
6.1 Introduction 60
6.2 Fold 61
6.3 Fault 62
6.4 Joint 63
6.5 Unconformity 64

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Chapter 07: Co-relation 65-68
7.1 Lithological Description 66
7.2 Previous Study 67
7.3 Co-relation 68
Chapter 08: Discussion & Conclusion 69-71
8.1 Discussion 70
8.2 Conclusion 71
Reference 72
Geological Map of Sitakund Anticline 73

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List of Figure
Figure No. Topics Page No.
0.1 In font of YPSA 01
2.1 Climate graph of Sitakund Anticline in 2020 19
2.2 Local People 20
2.3 Local Cultivation (Bean) 20
3.1 Stream 24
3.2 Gully 24
3.3 Gorge 24
3.4 Waterfall & Plunge pool 24
3.5 Pothole 24
3.6 Rapid 24
3.7 Pool & Riffle 24
3.8 Ridge & Valley 24
3.9 Reverse Fault 25
3.10 Joint 25
4.1 Measuring Attitude of Beds 28
4.2 Taking Photograph 28
4.3 Data Plotting on the Map 28
4.4 Collecting Sample 28
4.5 GPS (Global Positioning System) 29
4.6 Grain Size Comparator 29
4.7 Compass Clinometer 29
4.8 Measuring Tape 29
4.9 Hands Lens 29
4.10 Hammer 29
4.11 Field Notebook 29
4.12 Base Map 29
5.1.1 At the shahasradhara waterfall section 31
5.1.2 Geometrical Configuration of Waterfall 34
5.1.3 Shahasradhara Waterfall and Plunge pool 35
5.1.4 Stream 35
5.1.5 Rapid 35
5.1.6 Ridge & Valley 36
5.1.7 Landslide 36
5.1.8 Bedding 37
5.1.9 Lamination 37
5.1.10 Bioturbation 37
5.1.11 Sandstone 38
5.1.12 Shale 38
5.1.13 Silty Shale 38

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5.1.14 Lithological Succession of Shahasradhara Section 39
5.2.1 In font of Agnikand Temple 40
5.2.2 Gas Seepage 41
5.2.3 Stream 45
5.2.4 Pothole 45
5.2.5 Pool & Riffle 46
5.2.6 Point Bar 46
5.2.7 Ridge 46
5.2.8 Gully 46
5.2.9 Gorge 46
5.2.10 Bedding 48
5.2.11 Groove Cast 48
5.2.12 Lenticular Bedding 48
5.2.13 Mud Cast 48
5.2.14 Nodular 48
5.2.15 Lamination 48
5.2.16 Bioturbation 48
5.2.17 Baroz 48
5.2.18 Sandstone 49
5.2.19 Shale 49
5.2.21 Lithological Succession of Barabkund Section 50
5.3.1 Start Point of Chandranath Hill 51
5.3.2 Ridge 55
5.3.3 Y-shaped Valley 55
5.3.4 Bedding 56
5.3.5 Nodular 56
5.3.6 Lamination 56
5.3.8 Sandstone 57
5.3.9 Silty Sandstone 57
5.3.10 Lithological Succession of Chandranath Hill Section 58
6.1 Fold 61
6.2 Anticline of Fold 61
6.3 Fault in Shahasradhara waterfall 62
6.4 Reverse Fault 62
6.5 Joint in Chandranath Hill Section 63
6.6 Joint in Barabkund Section 63
6.7 Local Unconformity 64

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List of Table
Table No. Topics Page No.
1.1 Previous work in Sitakund Anticline 12
5.1 Attitude of Bed (Shahasradhara Section) 32
5.2 Attitude of Bed (Barabkund Section) 42
5.3 Attitude of Bed (Chandranath Hill Section) 52
7.1 Correlation 68

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List of Map
Map No. Topics Page No.
1.1 Satellite image of Sitakund Anticline 13
1.2 Location map of Sitakund Anticline 14
1.3 Sitakund Anticline In Chittagong District Map 14
2.1 Topographic map of Sitakund Anticline 16
2.2 Physiographic map of Sitakund Anticline 17
2.3 Drainage pattern of Sitakund 18
2.4 River system of Chittagong 18
3.1 Geological Setup of Sitakund Anticline 22
3.2 Sitakund Anticline Fold 25
3.3 Petrological Map of Sitakund Anticline 26

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Chapter One
INTRODUCTION
1.1 Background
1.2 Scope of Study
1.3 Objectives
1.4 Previous work
1.5 Study area

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1.1 Background
Geology is the study of visual earth
science. Field Studies offer several
unique advantages in solving geological
problems. A purpose may be economic
or scientific. Our purpose was scientific.
Field mapping is fundamental to all
geologic knowledge.
Geological fieldwork usually involves
the study and interpretation of rocks,
topographic forms, etc. Geologic Field
Work is a compulsory course of the
Geology and Mining Department,
which supplements practical
knowledge. The chief purpose of the
fieldwork is to get aquatinted with
different geologic field problems and
interpret them properly.
The geologic fieldwork deals with the
study and explanation of the rocks,
drainage patterns, and structural
features such as fold, fault, joint,
unconformity, and plotting this
geologic data on the base map.
For this reason, the Geology and Mining
Department of the University of
Barishal arranges annual field trips for
students. The department of Geology
and Mining arranged scheduled
fieldwork in Sitakund Hill Range under
the district of Chittagong.
Course Name: Field Geology I
Course Code: GMF 114
Course Credit Hours: 2 Credit
We are fifty-four students of the 1st
year B.S. (Hon’s) Session 2019-2020
made a field tour for six days. Our
investigation was based on the traverse
method. We were divided into nine
groups consisting of six members.
1.2 Scope of Study
In Sitakund Anticline, exposures that
are found along the waterfall area, hill
slopes, river valleys, anticlinal folded
structures, and rock types offer huge
scopes for geological investigations.
Through exposures, we can study its
attitude and lithology and observed
different morphological features and
the change in natural processes. We
prove that it is a clear anticline by
defining the axial plane.

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1.3 Objectives
Important Objectives of field report
are:
 To use maps (topographic and
geologic) to estimate distances,
visualize landforms and identify
geographic and geologic
features.
 To identify common minerals in
hand samples and in-field
exposures of rock using visual
clues and to identify the
common form of sedimentary
rock in hand samples and in-field
exposures using observations of
mineral composition and
texture.
 To identify common structures
and bed features in sedimentary
strata. Using a variety of tools
and instrumentation, students
will describe and quantify the
mineral, paleontological
composition, grain distribution,
textural properties, bedforms,
and structures of earth materials
and strata.
 To know how to collect data
process and analyze and
represent the collected data.
 To know how to make a field
report and for realizing about
completing the fieldwork.
 To know how to make a field
report and for realizing about
completing the fieldwork.
 Using observations and
measurements of lithological,
paleontological, and
geochemical properties, to
interpret the history and
environment of the formation of
rock samples and strata.
 To integrate data from
fieldwork, laboratory
measurements, library research,
and the course work to
formulate or evaluate a
hypothesis and to produce and
present oral reports based on
posters or digital media (e.g.
PowerPoint) that clearly and
accurately describe and
illustrate the backgrounds,
methods, data, and
interpretation relevant to a
particular project.
 To demonstrate proficiency
using digital photography and
image processing or drafting
software to generate scientific
illustrations, maps, diagrams, or
graphs. After all, and to will
apply critical thinking skills such
as inductive, deductive, and
mathematical reasoning to solve
geological problems using the
scientific method.

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1.4 Previous Work
S.N Geologists/Organization Work Time
01
The Indian Petroleum
Prospecting Company
Drilled three wells 1910-1914
02 The Burma oil company (BUC) Drilled a shallow well 1914
03
The oil and gas development
corporation (OGDC)
Conducted a
geological
investigation of the
area
1963-1964
04
Professor M.A. Latif and M.T.
Hossain.
Mapped the area
Geologically
1963-1965
(winter season only)
05
Professor M.A. Latif and M.T.
Hossain
Published analytic
writings on this hill
range.
1968
06 Momin Ullah
Published analytic
range.
1978
07
Dr. K.M. Hossain, and Dr. S.H.
Akhter
Published analytic
range.
1983
08 Petrobangla Drilled a well 1983
Table 1.1: Previous work in Sitakund Anticline
Also, the Geological Survey of Bangladesh, Petrobangla took several projects in this hill
range.
Moreover, students and teachers of the Department of Geology & Mining of the
University of Barishal, Department of Geology of the University of Dhaka, Department
of Geology & Mining of Rajshahi University, and Jahangirnagar University, and many
geologists study every year.

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Map 1.1: Satellite image of Sitakund Anticline
1.5 Study Area
Sitakund is one of the most familiar hill
ranges in Bangladesh. Sitakund is an
upazila under the Chittagong District. It
is situated in the northwestern part of
the Chittagong District.
The investigated area lies within the
latitude of 22°30ʼ N to 22°45ʼ N and the
longitudes of 91°35ʼ E to 91°50ʼ E and
is included in the survey of
Bangladesh topo sheet No. 79 N/10.
The distance between Sitakund and
Chittagong is 40 km whereas it is 185
km southeast of Dhaka City, the
capital of Bangladesh. It stands beside
the Dhaka Chittagong Highway and
Dhaka-Chittagong Railway line.
The Sitakund Anticline is about 68 km
long and 12-16 km wide and covers
about 840 sq. km.
Sitakund Anticline extends from Feni
River to Karnaphuli River whereas
Swandip Channel is on the western
side and Halda Valley is on the
eastern side of the hill range.
We went to three sections.
Shahasradhara section is situated on
the eastern side, Barabkund Section is
situated southern side, and
Chandranath Hill Section is situated
on the north-eastern side of Sitakund
Upazila.

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Map 1.2 : Location map of Sitakund Anticline
Map 1.3: Sitakund Anticline In Chittagong District Map

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Chapter Two
Physiography
2.1 Topography
2.2 Drainage pattern
2.3 Climatology
2.4 Population and Culture

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Map 2.1 : Topographic map of Sitakund Anticline
2.1 Topography
The topographic expression of the area
is the abrupt rise of the hill on the
eastern flank whereas the western
flank’s hills are buried under the alluvial
plain. (fig)
The Sitakund hill range is trending
NNW-SSE direction caused by folding.
(fig) The eastern flank of the hill
gradually merges with Halda Valley and
the western flank is abruptly
distributed by a major fault.
The average height of the Sitakund hill
range is 700 feet from sea level. The
height of the highest elevated area is
1156 feet from sea level. Based on the
general topography, the whole hill
range is divided into three major
physiographic zones. They are as
follows:
The Western Zone: This portion is
mainly covered with shallow depth of
alluvium that’s why it is also named “A
Zone of Buried Hill”. This zone extends
from the sea coast to the western
margins of the hills. Since the
sediments are encountered at a
shallow depth of alluvial cover.
The Middle Zone: The middle portion
of the hill range constitutes a strip of
landmasses, that make up the foothills
of the main range. The average
elevation is 100 to 250 feet. Due to
differential weathering, the zone shows
an inversion of topography and results
in a long escarpment. As a result, this
zone is named “The Zone of
Topographic Inversion”.
The Eastern Zone: The eastern
portion represents the maximum
elevation. The highest peak of this zone
is 1156 feet at the Chandranath
Temple. The area is still in its early
geomorphic youth and the work of sub
areal denudation is conspicuous. As a
result, the features like cliffs spur rapid
waterfalls, plunge pools, etc. are
present.

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Map 2.2 : Physiographic map of Sitakund Anticline

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Map 2.3: Drainage pattern of Sitakund
Map 2.4 : River system of Chittagong
2.2 Drainage Pattern
There are numerous valleys and
streams along and across the Anticline.
The steams are locally known as
‘Chara”. Most of the valleys and
streams of Sitakund are in the youth
stage. Some streams are perennial and
had a very narrow flowage. Two major
types of drainage patterns are seen.
One is the ‘Dendritic’ pattern. There are
no streams that are straight for a
hundred meters. All are curved and
dendritic. Generally found southern
and eastern part and the second is
‘Trellised’ drainage pattern in the north
and North-West part of this area.
But the drainage of this area is mostly
dendritic which indicates that the
underlying bedrock is uniform. In these
dendritic patterned streams or charas,
we found many geomorphic features
such as waterfalls, rapids, etc. The
general characteristics of those streams
in the area are demonstrated and
controlled by the geomorphic feature
available here like waterfalls, rapids,
potholes, gorge, V-shaped valley, etc.

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Figure 2.1 : Climate graph of Sitakund Anticline in 2020
2.3 Climatology
The weather on our observation days
was colder to warmer, with a sunny
day, no humidity, no rainfall, and
temperature is 16°C to 21°C. It was a
good time in December we visited
Sitakund. There are three distinct
seasons in the Sitakund area. They are
described below-
The summer: Begins in March
continues up to May with moderate
precipitation. As this mountainous area
has a huge amount of plantations so
summer heat is not so unbearable.
The monsoon: Starts in June and lasts
till October. During monsoon, the sky is
often overcast with dark clouds, and it
rains heavily accomplished by gusty
wind and occasionally with a cyclonic
storm.
The winter: It begins in November and
continues up to February, with cool,
calm, and pleasant weather.

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Figure 2.2 : Local People
Figure 2.3 : Local Cultivation (Bean)
2.4 Population and Culture
According to the census of 2001,
Sitakundhad a population of 298,528
distributed to55,837 units of
households (average household size
5.3), including 163,561 men and
134,967 women, or a gender ratio
of121:100. The average population of
component administrative units of the
Upazila is 4,072 for wards, 1,666 for
mahallas, 29,853 for unions, 5,060 for
mulas(revenue villages), and 5,060 for
villages reported by the census. Out of
the 69 mauzas here, 8 have less than 50
households, while 27 have more than
600 households. Of the villages, 8 have
a population of less than 250, while 29
have more than 2,500. As of 2001, the
population density of Sitakund was 692
inhabitants per square kilometer
(1,792/square mile). Apart from the
Bengali majority, there are several
small communities of ethnic minorities
in the area. Many of the resident
Rakhine people are believed to have
settled here during the Arakanese rule
of Chittagong (1459-1666), though the
event is not historically traceable.
The Rakhine population in Khagrachari
District migrated from the surrounding
area and built up their permanent
abode at Ramgarhin in the 19th
century. Other ethnic groups include
the recently migrated Tripuri people. In
the District of Chittagong which
includes Sitakund, the population ratio
by religion in 2001 wasMuslim83.92%,
Hindu13.76%, Buddhist2.01%, and
Christian 0.12%, with 0.19% following
other religions. In 1981, it was Muslim
82.79%, Hindu14.6%, Buddhist 2.23%,
and Christian0.21%, with 0.19%
following other religions. Chittagonian,
a derivative of Bengali spoken by 14
million people mainly in the Chittagong
district, is the dominant language. In
plain lands most of the people are
farmers. But there are also working
people like woodcutters, businessmen
or porters. There are many temples in
the Sitakund region such as
Chandranath, and Barabkund temples.
An enormous number of people come
here every year to meet on religious
occasions.

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Chapter Three
Geological Setup
3.1 Tectonics
3.2 Geomorphology
3.3 Structural Geology
3.4 Petrology

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Map 3.1 : Geological Setup of Sitakund Anticline
3.1 Tectonics
Sitakund anticline is a result of the
collision between the Burma plate in
the east and the Indian plate in the
west. It is situated in the
northwestern part of the Chittagong
district, between 22'34' N and 22'43'
N latitude and 91'38' E and 91'41' E
longitude. It is delimited in the north
by the Fini River, in the south by the
Karnaphuli, in the east by the Halda
River, and the west by the Swandwip
Channel. In a broader sense, the
Sitakund hill range acts as a water
divider between the Halda valley on
the east and the Swandwip channel
on the west. The structure is about 70
km long and 10-km wide.

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3.2 Geomorphology
We found various types of
geomorphic features in different
sections of our field trip. A short
description is given below:
Stream: A body of running water or
any other moving liquid under the
influence of gravity to lower levels in
a narrow, clearly defined natural
channel is called a stream. It has three
important roles in the formation of a
landscape: It erodes the channels in
which it flows, it transports materials
provided by weathering and slope
processes, and it produces a wide
variety of erosional and depositional
landforms. It was seen in all
Sections(Shahasradhara Section,
Barabkund Section, Chandarnarh Hill
Section).
Waterfall: A steep to vertical descent
of a stream course where it drops
over the edge of a plateau or where
erosion has worn away overhanging
softer rock. It was seen in
Shahasradhara Section. Because of the
force of the water, all waterfalls must
necessarily be relatively ephemeral
features.
Pothole: A pothole is a bowl-shaped,
circular, or cylindrical hole formed by
the grinding action of a stone in the
rock bed of a river of the stream. It
was seen in Barabkund Section.
Potholes are created by the abrasive
action of particles swirling in fast-
moving eddies. The rotational motion
of the sand and pebbles act like a drill
to bore the holes.
Plunge Pool: The water occupying a
deep hollow scoured in the bed of a
stream at the foot of a waterfall is
called a plunge pool. It was seen in
Shasradhara Section.
Ridge & Valley: A ridge is a geological
feature consisting of a chain of
mountains or hills that form a
continuous sharp elevated crest for
some distance. Ridges are usually
termed hills or mountains as well,
depending on size. A valley is a low
area between hills, often with a river
running through it. In geology, a
valley or dale is a depression that is
longer than it is wide. We had seen
the ridge & valley from the top of
Chandranath Hill Section and
Shahasradhara Section. In the
Sitakund hill range, we found mainly
shale and sandstone. Since sandstone
is more resistant, it undergoes less
weathering than shale. Therefore it
makes the ridge. In other cases, shale
undergoes more weathering and
forms a valley.
Gully: A gully is a landform created by
running water, eroding sharply into
soil, typically on a hillside. Gullies
resemble large ditches or small
valleys but are meters to tens of
meters in depth and width. When the
gully formation is in process, the
water flow rate can be substantial,
which causes a significant deep
cutting action into the soil. Gully was
seen in the Barabkund Section.

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Figure 3.1 : Stream Figure 3.2 : Gully
Figure 3.3 : Gorge
Figure 3.4 : Waterfall & Plunge pool
Figure 3.5 : Pothole Figure 3.6 : Rapid
Figure 3.7 : Pool & Riffle
Figure 3.8 : Ridge & Valley
Gorge: Gorge is a narrow passage
between mountains or the wall of the
canyon, especially one with steep and
rocky walls. Most gorges were formed
by a process of long-time erosion
from a plateau or table-land level. The
cliffs form because harder rock strata
that are resistant to erosion and
weathering remain exposed on the
valley walls. We’ve seen Gorge at
Balukhali Section and Chandranath
Hill Section.
Rapid: A rapid is a part of the river
where the current is very fast because
of the relatively steep gradient of the
river bed at that place causing an
increase in water flow and
turbulence. It was seen in the
Sahasdhara Section.
Pool and Riffle: Pool and riffle are the
deep and shallow portions of an
undulating stream bed. Pools are
most easily seen in a meandering
stream where the outer edge of each
meander loop is deep and undercut;
riffles form in the shallow water of the
short, straight, wide reaches between
adjacent loops. The pools and riffles
form sequences spaced at a repeating
distance of about five to seven widths
of the channel and often appear in-
stream development long before the
stream produces visible meanders. It
was seen in Barabkund Section.

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Map 3.2 : Sitakund Anticline Fold
Figure 3.9: Reverse Fault
Figure 3.10: Joint
3.3 Structural Geology
Sitakund is mainly a Fold. The
Sitakund fold is an elongated,
asymmetrical, box-type doubly
plunging anticline. The axis of the fold
is running in the NNW-SSE direction,
parallel to the general trend of the
regional strike. Both the flanks of the
anticline merge into the alluvial plain
of the Feni River in the north and the
Karnaphuli in the south due to its
doubly plunging nature. For a lack of
infrastructure in Bangladesh, this
anticline is one of the few regularly
surveyed structures in the country.
The syncline from Sitakund separates
the eastern end of the Feni structure
located in the folded flank of the
Bengal foredeep. In Sitakund, we also
found many structural features. They
are:
Fault: A fault is a planar fracture or
discontinuity in a volume of rock
across which there has been
significant displacement as a result of
rock-mass movements. It was seen in
Shahasradhara Section.
Joint: Joints are brittle-fracture
surfaces in rocks along which little or
no displacement has occurred. It was
seen in Barabkund Section and
Chandranath Hill Section.
Unconformity: An unconformity is a
surface of erosion or non-deposition
that generally separates younger
strata from older ones.
Fault Line

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Map 3.3 : Petrological Map of Sitakund Anticline
3.4 Petrology
The Upper Bhuban Member in the
Sitakund anticline is constituted by
the light gray, light yellow, and
greenish-gray sandstone and
siltstone with dark gray, bluish-black
and black finely laminated silty shale
to shale. The lithofacies of massive
sandstone(Sm), turbidite sandstone
(ST), flat bedded sandstone-siltstone
(Sh), ripple cross-laminated
sandstone-siltstone (Sr), laminated
sandstone-siltstone (Sl), lenticular
laminated sandstone-siltstone-shale
(Sll), wavy laminated silty shale to
shale (Fw), laminated shale (Fl) with
sub-facies black shale (Flbk) and blue
shale (Flb) and mudstone (Fm) have
been delineated in this member.

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Chapter Four
Methodology
4.1 Method of Study
4.2 Lab Investigation
4.3 Equipment

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Figure 4.1: Measuring Attitude of Beds
Figure 4.2: Taking Photographs
Figure 4.3 : Data plotting on the map
Figure 4.4: Collecting Sample
4.1 Method of Study
Our investigation was based on the
traverse method. The area has been
surveyed along the roads and streams
where the bedrocks were exposed and
outcrops were found. We were divided
into nine groups consisting of six
members guided by honorable
teachers. The following methods were
used during the fieldwork-
Measuring Attitude of Beds:
While the investigation of exposure was
taken, the strike direction, dip
direction, and amount of dip of the bed
were measured with the help of
Clinometers and then written in the
field notebook.
Describing lithology:
The lithology of the exposures was
described and inscribed on the
notebook.
Collecting samples:
We collected some rock samples and
some significant sedimentary
structures from the explored areas.
Identify Mineral Constituents:
The constituent minerals and grain size
of rock specimens were identified with
the help of a lens.
Data plotting on the supplied map:
During our investigation, we found
some data on the attitude of beds and
we tried to understand the lithology of
the beds.1 cm on the map represents
200 meters on the ground.
Taking Photographs:
Photographs of well-exposed
geomorphic features, vegetation
structures, and topography were taken
in each section.

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Figure 4.5: GPS
Figure 4.6: Size comparator
Figure 4.7:Compass clinometer
Figure 4.8: Measuring tape
Figure 4.9: Hand lens Figure 4.10: Hammer
Figure 4.11: Field Notebook
Figure 4.12: Base Map
4.2 Lab Investigations
The rock specimens and samples
collected during the field survey were
investigated in the Barishal University
mineralogy Lab. So, we can able to
determine the fabric or other optical
properties of rock and mineral.
4.3 Equipment
GPS Navigation Device:
To measure the position (latitude and
longitude) of the station’s location.
Compass clinometer: Used in
measuring the attitude of beds, that is
the dip direction, the amount of dip,
and the strike direction of the beds.
Hammer & Scrapper: To collect
samples and find out proper beds.
Acid bottle and dropper: Used for
identifying rock nature whether it is
calcareous or not.
Measuring tape: To measure distance.
Hand Lens: To see grain size.
Grain Size Comparator: To define grain
size.
Base Map: To plot rocks data and
lithology.
First Aid Box: For First aid, if needed.
Also, we took a field notebook(6”×4”),
pen, pencil(also color), Marker pen,
Eraser, Diagonal scale, Set square,
writing paper, Graph paper, Tracing
paper, Pocket knife, Sample bag,
Camera, Flash Light, Water Bottle, and
enough cloth, Toiletries kit, and
necessary equipment according to our
needs.

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Chapter Five
Description of Individual Section
 Sections
5.1 Shahasradhara Section
5.2 Barabkund Section
5.3 Chandranath Hill Section
 Topics to be described
 Introduction
 Attitude of Bed
 Geomorphic features
 Sedimentary Structure
 Petrology
 Lithological Succession

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Figure 5.1.1: With our honorable teachers at
shahasradhara waterfall section
5.1 Shahasradhara Section
5.1.1 Introduction
Our 1st
day of fieldwork was in
Shahasradhara Section. There was a
waterfall called Shahasradhara
Waterfall. Shahasradhara Waterfall is in
the evergreen forest of Chandranath
Reserve Forest block of Sitakund
Upazilla of Chittagong. The
Shahasradhara eco-park is 35 km from
Chittagong city, located on the east side
of the Dhaka-Chittagong Highway and
railway in the north. During the year
other than the monsoon, this fountain
is less water. The fountain is found 7 km
away from the main gate of the eco-
park, with a brick path. There is a
stairway from the top of the park to the
waterfall. So, one just needs to do a
relaxing walk to reach the waterfall. But
beware, you’d have to do some hard
work during your return.
The shahasradhara waterfall is a
narrow waterfall with only a single
drop. The flow of water is not that
heavy and it doesn’t produce much
noise either. This waterfall is the upper
stream of the Suptadhara Waterfall.
There is a small pool at the base of the
waterfall. Since this is easy to access,
that’s why a lot of people visit it, and
sometimes they are careless about
littering. When we went there during
the summer we didn’t see any water in
the waterfall. The waterfall can be seen
from the top of the eco-park(if anyone
does not wish to climb down and up).
Also, we didn’t find any path that would
lead us to the top of the waterfall. For
sure there is a path which local people
might know. But as tourists, we
couldn’t find it. I’d love to see the photo
of the top of this waterfall (if anyone
has done it).
Date: 29 December
2021(Wednesday)
Start Time: 7:15 AM
Weather: Cloudy
Temperature: 17°C
Start Point: Base Camp (YPSA)
GPS of Start Point: 22°36’28” N
91°39’49” E
End Point: Base Camp (YPSA)
GPS of End Point: 22°36’28” N
91°39’49” E

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5.1.2 Attitude of Bed
Station Location Lithology
Attitude of Bed
Rock Name
S.D D.D A.D
01
22°36’90” N
91°40’42” E
Alteration of
yellowish-brown
incline bedded
shale and
Reddish-brown
Siltstone.
Grain Size:
0.025mm-2mm
N46°E N44°W 50° Silty shale
02
22°36’80” N
91°40’41” E
Fine-grain
yellowish-brown
color Sandstone.
It is porous and
permeability is
high. Grain Size:
< 1/16 mm
N70°W N160°W 30° Sandstone
03
22°36’57” N
91°41’36” E
Brownish Gray-
colored Silty
Shale. It Shows
lamination.
Grain Size: 0.004
mm- 0.063 mm
N105°E N15°E 15° Silty Shale
04
22°36’50” N
91°41’32” E
Brownish Gray-
colored
Sandstone. It
shows the
sedimentary
structure found
in the valley and
channel.
Lamination is
found.
Grain Size: 0.125
mm – 0.25 mm
N78°E N168°E 20° Sandstone

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05
22°36’51” N
91°41’34” E
It is sandstone-
dominated. Light
gray color
sandstone(highly
compacted).
Fissile shale is
visible.
N20°W N70°E 20° Sandstone
(some shale)
06
22°36’23” N
91°41’10” E
Sandstone is
mica silt. It is one
kind of fossil,
plant root.
N18°W N72°E 2° Sandstone
07
22°36’23” N
91°41’10” E
Sandstone is
found that
contains mica,
quartz, sand, and
iron.
N166°E N76°E 30° Sandstone
08
22°36’70” N
91°41’30” E
Yellow-colored
pure sandstone.
Grain size: 0.125
mm – 0.25 mm
N64°E N26°W 32° Pure
Sandstone
Table 5.1: Attitude of Bed(Shahasradhara Section)

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Figure 5.1.2: Geometrical Configuration of Waterfall
5.1.3 Geomorphic Feature
We found many geomorphic features in the Shahasradhara Section. The main
geomorphic features are being described below-
Waterfall: A steep to vertical descent of
a stream course where it drops over the
edge of a plateau or where erosion has
worn away overhanging softer rock.
Because of the force of the water, all
waterfalls must necessarily be
relatively ephemeral features.
We found a waterfall in this section
called “Shahasradhara Waterfall”. Its
GPS location is 22°36’51” N and
91°41’34” E. The height of the observed
waterfall in the Shahasradhara section
was 36.013 meters. We measured its
height by using a compass clinometer
and the help of basic trigonometry.
Measuring the height of waterfall
Here,
The height of the person is,
BE = CD = 1.3716 m
Distance between person and waterfall is,
BC = ED = 20 m
We measure the angle by the clinometer,
<ABC = 60°
Now,
The height of the waterfall is,
AD = ?
Calculation :
Waterfall height, AD = AC + CD
Person height, CD = 1.3716 m
AC = BC × tan <ABC
= 20 m × tan 60°
= 34.64 m
AD = AC + CD
= 34.64 m + 1.3716 m
= 36.013 m
So, The height of the waterfall is, 36.013 m

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Figure 5.1.3: Shahasradhara Waterfall and Plunge pool
Figure 5.1.4: Stream
Figure 5.1.5: Rapid
Plunge Pool: The water occupying a
deep hollow scoured in the bed of a
stream at the foot of a waterfall is
called a plunge pool.
Stream: A body of running water or any
other moving liquid under the influence
of gravity to lower levels in a narrow,
clearly defined natural channel is called
a stream. It has three important roles in
the formation of a landscape: It erodes
the channels in which it flows, it
transports materials provided by
weathering and slope processes, and it
produces a wide variety of erosional
and depositional landforms.
Rapid: A rapid is a part of the river
where the current is very fast because
of the relatively steep gradient of the
river bed at that place causing an
increase in water flow and turbulence.
Ridge & Valley: A ridge is a geological
feature consisting of a chain of
mountains or hills that form a

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Figure 5.1.6: Ridge and Valley
Figure 5.1.7: Landslide
continuous sharp elevated crest for
some distance. Ridges are usually
termed hills or mountains as well,
depending on size. A valley is a low area
between hills, often with a river running
through it. In geology, a valley or dale is
a depression that is longer than it is
wide.
Landslide: A landslide is defined as the
movement of a mass of rock, debris, or
earth down a slope. Landslides are a
type of "mass wasting," which denotes
any down-slope movement of soil and
rock under the direct influence of
gravity.

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Figure 5.1.8: Bedding
Figure 5.1.9: Lamination
Figure 5.1.10: Bioturbation
5.1.4 Sedimentary Structure
The sedimentary structures, observed here are given below:
Bedding: Bedding is a term used for a
structure occurring in granite and
similar massive rocks that allow them
to split into well-defined planes
horizontally or parallel to the land
surface, thickness more than 1cm.
Lamination: Lamination is a small-scale
sequence of fine layers that occurs in
sedimentary rocks. Laminations are
normally smaller and less pronounced
than bedding. Thickness is less than 1
cm.
Bioturbation Structure: Bioturbation is
defined as the reworking of soils and
sediments by animals or plants. These
include burrowing, ingestion, and
defecation of sediment grains.
Bioturbating activities have a profound
effect on the environment and are
thought to be a primary driver of
biodiversity.

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Figure 5.1.11: Sandstone Figure 5.1.12: Shale
Figure 5.1.13: Silty Shale
5.1.5 Petrology
The lithology of this area includes sandstone, shale, and silty shale.
Sandstone: the rock is composed of
yellowish-brown colored, fine to
medium-grained, very thinly to thickly
bedded, loose compacted sand-size
particles.
Shale: The rock is composed of bluish-
gray colored, thinly to thickly
laminated, clay-sized particles.
Silty shale: the rock is composed of
bluish gray-colored, thinly to thickly
laminated, medium to fine-grained silt,
and clay size particles.

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5.1.6 Lithological Succession
The lithological succession of the Shahasradhara Section is given below:
5m
10m
15m
20m
25m
30m
Thickness
Clay(Shale)
Silt
Sand
fine Medium Coarse
Grain Size
0m
Figure 5.1.14: Lithological Succession of Shahasradhara Section
Ex-01
Ex-02
Ex-03
Ex-04
Ex-05
Ex-06
Silt
Clay
Sand

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Figure 5.2.1: In font of Agnikund Temple
5.2 Babarkund Section
5.2.1 Introduction
Our 2nd
day of fieldwork was in
Barabkund Section. There was a gas
seepage. The elevation of this area is
200 feet- 600 feet from sea level. It is
located on the east side of the Dhaka-
Chittagong Highway and Railway. In this
area, most of the rock that we found is
Shale. Siltstone, Sandstone, and other
sedimentary rock are also found. This
area is an evergreen forest area.
Calcareous Sandstone is also found in
this area.
There is a temple name Agnikund
Temple and its age is more than
hundreds of years ago. On the path,
there will be a huge piece of hilly soil.
The soil has softened due to the
wetness of the rain. But without the
rainy season, it is purely hard. The most
interesting thing in the Barabkund
Section is Gas Seepage. The Agnikund
Temple is located beside this gas
seepage.
Date: 30 December 2021(Thuesday)
Start Time: 8:07 AM
Weather: Hazy
Temperature: 17°C
91°39’49” E
91°39’49” E

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Figure 5.2.2: Gas Seepage
 Gas Seepage
Gas is a very important economic
resource. Natural gas is an energy
source often used for heating, cooking,
and electricity generation. It is also
used as fuel for vehicles and as a
chemical feedstock in the manufacture
of plastics and other commercially
important organic chemicals. Various
Gas Seepages were found almost all
over Sitakund. One of the Gas Seepages
was at Barabkund Temple in
Barabkund, which was investigated.
There we found an amount of very little
gas at the temple, which helps to light
up the fire beside that. Mainly most of
the temples are built centering gas
seepage.
Gas is formed by organic matter in
sedimentary rocks. At first plant or
animal, fossils are cooked beneath the
surface and the source rock is
transformed into kerozin. By getting
heated this kerozin releases gas. This
gas is then trapped in a reservoir. A
layer of shale acts as a seal in the
Sitakund gas reservoir. Without the
seal, gas cannot be trapped in the
reservoir. The seal must be non-porous.
It helps the rock to be preserved. The
stronger the seal is, the more gas will be
deposited. When the Seal cracks, gas
started to leak from the Reservoir. This
is what we find at the top of the hill as
“Gas Seepage”.

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Station Location Lithology
Attitude of Bed
Rock Name
S.D D.D A.D
01
22°34’53” N
91°41’22” E
Bluish gray Shale
dominated and
also yellowish
brown
sandstone.
Planer
lamination,
inclined bedding,
Lenticular
bedding, and
Bioturbation are
found.
N10°E N80°W 26° Sandy Shale
02
22°34’54” N
91°41’24” E
Yellowish-brown
Shale and a
minor amount of
sandstone.
Wavy bedding
due to turbidite.
N178°E N92°W 8° Sandy Shale
03
22°34’54” N
91°41’28” E
Bluish gray-
colored shale
dominated.
Concretion and
Reverse graded
bedding are
found.
N185°E N85°W 5° Shale
04
22°34’51” N
91°41’30” E
Light bluish-gray
colored Shale.
Upper bedding
shows light color
due to oxidation.
Flaser bedding
(Sandstone) and
concretion are
found.
N150°E N120°W 20° Shale(some
sandstone)
05
22°34’51” N
91°41’30” E
Light greenish
gray colored
Shale.
N160°E N70°E 38° Shale

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06
22°34’50” N
91°41’32” E
Yellowish-brown
colored
sandstone.
Iron concretion
is found.
N180°E
(True
Dip)
N90°E 38° Sandstone
07
22°34’50” N
91°41’36” E
Pure Shale is
found.
Color: Dark
Bluish Gary
Pure Shale
08
22°34’50” N
91°41’35” E
Greenish brown
colored Shale. A
minor amount of
sandstone and
siltstone.
Ripple and
potholes are
found.
N165°E N105°W 42° Silty Shale
(Some
sandstone
also)
09
22°34’51” N
91°41’38” E
Light brown
colored loose
shale and a
minor amount of
compacted
sandstone.
N145°E N55°E 60° Sandy Shale
10
22°34’52” N
91°41’40” E
Medium-light
gray-colored
shale and a
minor amount of
siltstone and
sandstone.
Nodular
structure and
Joint are found.
N158°E N112°w 78° Silty
Shale(some
sandstone
also)
11
22°34’52” N
91°41’39” E
Gray-colored
siltstone and
Fleasure bedding
of Sandstone.
Baroz is found.
N165°E N105°W 50° Sandy
Siltstone
12
22°34’52” N
91°41’40”
1. Light gray
colored
shale and
Fleasure
bedding
are found.

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2. Medium-
light gray-
colored
shale and
Fleasure
bedding
are found.
3. Gray-
colored
shale and
Lenticular
bedding
are found.
13
22°34’53” N
91°41’42” E
Dark brown
colored shale.
Fleasure
bedding, Contain
Iron and
lamination are
found.
N148°E N122°W 40° Shale
14
22°34’54” N
91°41’55” E
Brown colored
loose shale
N70°W N20°E 20° Shale
15
22°34’58” N
91°41’58” E
Greenish brown
colored shale.
Nodular
structure is
found.
Table 5.2: Attitude of Bed (Barabkund Section)

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Figure 5.2.3: Stream Figure 5.2.4: Pothole
The main geomorphic features are described below.
Stream: There were a lot of streams
that were not so deep in water as it was
a dry season. A body of running water
or any other moving liquid under the
influence of gravity to lower levels in a
narrow, clearly defined natural
channel.
Pothole: we also found some bowl-
shaped, circular, or cylindrical holes
formed by the action of moving water
in the rocky bed of a stream and
creating a pot-shaped hole Which is
known as a pot whole.
Pool and Riffle: A pool is characterized
by a water surface profile less than the
mean stream gradient and finer bed
materials, whereas a rifle has a water
surface slope steeper than the mean
stream gradient and is composed of
coarser bed materials.
Point bar: We observed that the
streams had a significant characteristic
that they had water quantity and
velocity variation. A point bar is a
depositional feature made of alluvium
that accumulates on the inside bends of
streams and rivers below the slip-off
slope. Point bars are found in
abundance in mature or meandering
streams.
Ridge: A general term for a long
narrow, usually sharp-crested, and with
steep sides, e.g. an extended upland
between valleys. It was seen in this
section.
Gorge: Gorge is a narrow passage
between mountains or the wall of the
canyon, especially one with steep and
rocky walls. Most gorges were formed
by a process of long-time erosion from
a plateau or table-land level. The cliffs
form because harder rock strata that
are resistant to erosion and weathering
remain exposed on the valley walls.
Gully: A gully is a landform created by
running water, eroding sharply into soil,
typically on a hillside. Gullies resemble
large ditches or small valleys but are
meters to tens of meters in depth and
width. When the gully formation is in
process, the water flow rate can be
substantial, which causes a significant
deep cutting action into the soil.

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Figure 5.2.5: Pool & Riffle
Figure 5.2.6: Point Bar
Figure 5.2.7: Ridge
Figure 5.2.8: Gully Figure 5.2.9: Gorge
Point Bar

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We observed many sedimentary structures. They are bellowed:
Bedding: On our whole field survey we
found a lot of bedding that was
expressed by work unit of granular
tabular or lenticular form. Generally, a
bed or structure is an individual layer of
rocks more than 1cm thick.
Lenticular Bedding: Lenticular bedding
is a sedimentary bedding pattern
displaying alternating layers of mud and
sand. Formed during periods of slack
water, mud suspended in the water is
deposited on top of small formations of
sand once the water's velocity has
reached zero.
Wavy Bedding: Wavy bedding occurs
when mud is deposited over the whole
area of a bed of rippled and/or cross
stratified sand.
Lamination: We also found some
structures that were likely to be
bedding but not so thick as bedding. We
identified those as lamination which is
a small-scale sequence of fine layers
that occurs in sedimentary rocks.
Laminations are normally smaller and
less pronounced than bedding.
Groove cast: We got a sedimentary
structure that was curved outwards
which was named groove casts and
they are sedimentary structures found
on the bases of certain strata that
indicate small-scale grooves or
irregularities. Generally, older strata
are curved inward.
Nodular structure: As much as we
became closer to the axis we found
some structures that were moderately
hard bodies of rock similar to
concretions. Nodules may also form by
the selective precipitation of dissolved
minerals that completely replace the
original Sediments.
Mud cracks: Mud Cracks are polygonal
cracks formed as the mud dried. Mud
Cracks indicate shallow water. They are
used to show which way up.
Bioturbation Structure: Bioturbation is
defined as the reworking of soils and
sediments by animals or plants. These
include burrowing, ingestion, and
defecation of sediment grains.
Bioturbating activities have a profound
effect on the environment and are
thought to be a primary driver of
biodiversity.
We can identify the Bioturbation by
observing Baroz. Baroz is faeces of
organism.

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Figure 5.2.10: Bedding Figure 5.2.11: Groove Cast Figure 5.2.12: Lenticular Bedding
Figure 5.2.13: Mud Cast
Figure 5.2.14: Nodular
Figure 5.2.16: Bioturbation Figure 5.2.17: Baroz

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Figure 5.2.18: Sandstone
Figure 5.2.19: Shale
5.2.5 Petrology
The lithology of this area includes sandstone, shale, and silty shale.
Sandstone: This rock sample was
yellowish-brown in color, fine to
coarse-grained, very thinly to thickly
bedded, moderately to well-sorted,
loose compact sandstone composed of
interbeds of silt size particles. The
cement materials are Arrhenius and
ferruginous. The rock was yellowish-
brown, thickly laminated, medium to
fine-grained silty shale. The cementing
materials are Arrhenius.
Shale: The rock sample was bluish-gray,
thinly to thickly laminated, very fine-
grained silt to sand-sized. Some thin
beds are calcareous fine-grained
sandstone to claystone.
Silty shale:
Silty Shale: The rock is composed of
bluish gray-colored, thinly to thickly
laminated, medium to fine-grained silt,
and clay size particles.

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The lithological succession of the Barabkund Section is given below:
05 m
0 m
10 m
15 m
20 m
Thickness
Clay (Shale) Silt Sand
Grain Size
Fine Medium Coarse
Silt
Sand
Clay
Figure 5.2.21: Lithological Succession of Barabkund Section

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Figure 5.3.1: Start point of Chandranath Hill
5.3 Chandranath Hill Section
5.3.1 Introduction
Chandranath Hill is the eastern part of
the Himalayas separated from the
Himalayas. This hill goes south and
southeast of the Himalayas and crosses
the Feni River through Assam and
Tripura states of India and joins
Chittagong, Bangladesh. From the Feni
river to the Chittagong city, it is about
70 kilometers long. Sitakunda Eco Park
is built on the foothills of this. The
Chandranath Temple, which is located
on the east side of Sitakunda city, is
about 1152 feet (around) high and is
the highest place in the Chattogram
district. The height of the Rajbari
hummock is 889 feet and the height of
the Sajidhala is 801 feet. The hill height
has come down very near the city of
Chittagong. Chandranath hill is one of
the great places for those trekkers who
likes trekking.
These hills are located in Sitakunda
which is a land of outstanding natural
beauty. From Sitakunda it is around
4.5km far. Chandranath has small hill
groups. On the way to the hill, tourists
will see some religious places Hindu
religion. This hill area has various kinds
of trees. Here tourists can see the
gardens of fruits like Guava, Mango,
Coconut, etc. It is easy from other
trekking to climbing up and down on
the hilly way by the stairs. This area has
some people called Tipra and they have
a village. The hills look very marvelous
during the rainy season, because of the
rainfall on the trees and the hills look
very awesome. But as well, it is very
dangerous to climb this hill.
Date: 31 December 2021(Friday)
Start Time: 8:10 AM
Weather: Hazy
Temperature: 18°C
91°39’49” E
91°39’49” E

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Station No GPS Lithology S.D D.D A.D
01 22⁰34’51” N
91⁰41’53” E
Silty shale;
its color light
gray, grain
size less than
0.004mm
shale
dominated
02 22⁰37’47” N
91⁰40’40” E
Silty shale;
its color light
gray, shale
dominated,
it has silt
also, silt is
gray color
and color of
silt is
yellowish-
brown,
moderately
faulted, not
highly
compacted,
iron
concretion,
the thickness
of bed 7.2cm
03 22⁰37’50” N
91⁰40’47” E
Silty shale;
shale
dominated.
Minor shale,
shale color is
gray and silt
color is
yellowish-
brown,
moderately
N93⁰W N5⁰E 5⁰

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faulted, not
highly
compacted,
iron
concretion
04 22⁰37’44” N
91⁰40’47” E
Calcareous
shale; sand
shale
alteration, its
color is light
gray, shale
dominated,
pure shale in
lower but
upper in silt
and shale
alteration,
nodular find
in shale,
shale is not
found
because it’s
color is
yellow color
not dark
brown,
highly
compacted
shale
96⁰NW 20⁰NE 20⁰
05 22⁰37’54” N
91⁰40’49” E
Nodular
structure;
fissile shale,
flauser
bedding,
color is
yellowish-
brown
N140⁰W N20⁰E 20⁰
06 22⁰37’54” N
91⁰40’52” E
Gray to
yellowish-
brown color,
S64⁰W N26⁰E 26⁰

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upper
portion
sandstone,
middle
portion
sandstone,
lower
portion
shale, highly
compacted
07 22⁰37’54” N
91⁰40’52” E
Silty shale;
fissile shale.
Yellowish-
brown color,
split into a
thin layer
N20⁰W N6⁰E 6⁰
08 22⁰38’01” N
91⁰41’02” E
Pure
sandstone,
yellowish-
brown color,
bioturbation,
fine to
medium
grain
size(.06-.25)
N20⁰W N5⁰E 5⁰
09 22⁰38’2” N
91⁰41’2” E
The color
olive green
contains Cl
Table 5.3: Attitude of Bed (Chandranath Section)

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Figure 5.3.2: Ridge
Figure 5.3.3: V-Shaped Valley
Many Geomorphic features are observed in this section. They are:
Talus: Talus is the triangular-shaped
structure where soil creep accumulated
at the bottom of the mountain.
Regolith: Regolith is a layer of loose,
heterogeneous superficial material
covering solid rock, including dust, soil,
broken rock, and other related
materials present on the earth.
V-shaped valley: Rivers flow through V-
shaped valleys in their upper course.
They are usually found in mountains
and hills. They are so-called because
they often have steps.
Ridge: A general term for a long
narrow, usually sharp-crested and with
steep sides, e.g. an extended upland
between valleys. It was seen in this
section.

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Figure 5.3.4: Bedding
Figure 5.3.5: Nodular
Bedding: Bedding (also called
stratification) is one of the most
prominent features of sedimentary
rocks, which are usually made up of
‘piles’ of layers (called ‘strata‘) of
sediments deposited one on top of
another.
Every stratum is characterized by its
lithology (composition), sedimentary
structures, grain size, and fossil content
that make it unique and different from
the strata that lie above and below it.
Every layer represents an event, a
moment in the geological time when
chemical, biological, and physical
conditions led to the deposition of a
specific rock layer. An event in the
sedimentary record could have lasted
thousands of years to a few minutes. In
any case, when looking at a sequence of
strata, we are looking through the
sequence of events that occurred in a
sedimentary basin over the geologic
time.
Lamination: In geology, lamination is a
small-scale sequence of fine layers
(laminae; singular: lamina) that occurs
in sedimentary rocks. Laminae are
normally smaller and less pronounced
than bedding. Lamination is often
regarded as planar structures one
centimeter or less in thickness, whereas
bedding layers are greater than one
centimeter. However, structures from
several millimeters to many
centimeters have been described as
laminae. A single sedimentary rock can
have both laminae and beds.
Nodular structure: As much as we
became closer to the axis we found
some structures that were moderately
hard bodies of rock similar to
concretions. Nodules may also form by
the selective precipitation of dissolved
minerals that completely replace the
original Sediments.

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Figure 5.3.8: Sandstone
Figure 5.3.9: Silty Sandstone
5.3.5 Petrology
Silty shale: It is shale-dominated. It has
minor silt. Shale is a laminated or fissile
clastic sedimentary rock that is
composed of a predominance of silt
and clay and other minerals, especially
quartz and calcite. Characteristic
properties of shale are breaks along
thin laminae or parallel layering or
bedding called fissility. It is the most
abundant sedimentary rock. The
composition (silt and clay) of shale is in
a category of sedimentary rocks known
as mudstone. The difference between
shale to mudstone is fissile and
laminated seen. Shale rock readily into
thin pieces along the laminations.
Sandstone: Sandstone is a sedimentary
rock composed of sand-size grains of
mineral, rock, or organic material. It
also contains a cementing material that
binds the sand grains together and may
contain a matrix of silt- or clay-size
particles that occupy the spaces
between the sand grains.
Silty sandstone: It is sandstone-
dominated. Its color is yellowish-
brown. It is split into a thin layer.

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The lithological succession of Chandranath hill section is given below:
Clay Sand Silt Medium
Fine Coarse
Sand
Grain Size
50 m
40 m
30 m
10 m
20 m
0 m
Figure 5.3.10: Lithological Succession of Chandranath Hill Section

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Chapter Six
Structure
6.1 Introduction
6.2 Fold
6.3 Fault
6.4 Joint
6.5 Unconformity

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6.1 Introduction
Structure is a spatial and geometrical
configuration of rock components.
Sitakund is a hilly region which is the
south-eastern part of Bangladesh.
There is a macroscopic anticline in this
area which tends NNW-SSE direction. It
is a single anticline and doubly plunging
asymmetrical fold. Its western flank is
suffered by a major faulting and its
strike is almost parallel to the main
structure. We found joints, micro faults,
fractures, etc. major structures, and
some significant sedimentary
structures in different sections while
investigating the region.
In this area, we found macroscopic and
mesoscopic structures.
Macroscopic Structure: Macroscopic
structures are large-scale structures
beyond the vision which is measured by
the satellite or drone camera.
The macroscopic structural features
are-
 Fold
 Fault
Mesoscopic Structure: Mesoscopic
structures are medium-scale structures
within the vision which orientations are
measurable in individual outcrops.
The mesoscopic structural features are-
 Joint
 Unconformity
 Small scale fault

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Figure 6.1: Fold
Figure 6.2: Anticline of Fold
6.2 Fold
Folds are wavy undulations in the
stratified rocks of the earth’s crust. One
of the most significant structures of the
investigated area is folding. Sitakund
anticline represents a large anticline
that lies in the western flank of Bengal’s
foredeep. The hill range is an
asymmetrical structure. The axis of the
fold is running in the NNW-SSE
direction parallel to the general trend
of the regional strike old axis of
Bangladesh.
Criteria for folding:
From the measurement of the
area, we found rock beds dip in
opposite directions along an
imaginary line, which is called
“Fold axis”. It is observed that
the westernmost outcrops show
overturning of bed, probably
due to the drag along the fault
plane. Shale is the oldest rock
unit in the axial region. So it
forms the core of the fold. Bed in
the unit in opposite direction
with the low amount of dip
(between 30-5) at the place. It is
an indication of an anticline axis
running through the unit. Older
rock is deep towards the east
and exposed at the western part
of the fold. The western flank is
steeper and shorter than the
eastern flank and the attitude of
the beds of those flanks is not
uniform. The broad and early flat
crustal part and high dip of
flanks are an indication of box-
like anticline fold Sitakund.

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Figure 6.4: Reverse Fault
Figure 6.3: Fault in Shahasradhara Waterfall
6.3 Fault
A fault is a break in the rocks that make
up the Earth's crust, along which rocks
on either side have moved past each
other. Major faulting lies in the eastern
flank of the anticline and has been
recognized based on abrupt changes in
topography, lithology, and structural
irregularity. These indicate a major
fault occurs in the eastern flank of the
anticline. By this, we can say that the
Sitakund hill range fault runs NNW-SSE
which is roughly parallel to the axis of
the anticline. Total Sitakund hill range
acted as a hanging wall and the western
flank acted as a footwall. This footwall
is covered by an alluvial plain.
But well-exposed joints are
found in the Sahasradhara
section. We found a prominent
fault line which is an indicator of
fault. That was found in the
western flank of the anticline.
Criteria for Faulting: In Sitakund
hill ranges some observations
ensure us to be the presence of
a fault and the criteria are given
here- There some discontinuity
in structure in the Sitakund
anticline and an abrupt change
in attitude suggests that a fault
line may have located there.
With having a high amount of
dip the Hill range starts from the
western alluvial plain suddenly.
This sudden traction indicates
faulting and a comparatively
high amount of dip in a short
distance near the alluvial plain
and hill range may also suggest
the faulting. Although there is no
repetition of strata is founded,
several missions of strata
indicate the presence of a fault.
The western flank contains the
Silty shale unit but the eastern
flank does not. Besides the
discontinuity of Massive
sandstone and Sandy shale unit
between two flanks can give the
confirmation of displacement of
the rock strata which indicates a
major fault.
Fault Line

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Figure 6.5: Joint in Chandranath Hill Section
Figure 6.6: Joint in Barabkund Section
6.4 Joints
Joints are brittle-fracture surfaces in
rocks along which little or no
displacement has occurred. Joints are
observed in more resistant sandstone
and shale of the Bhuban Formation.
Joints are the most common and
abundant structure on the surface of
the earth. Sitakund hill range is a highly
jointed surface. Most of these joints
have been originated at the time of
folding.
Between our investigated areas
numerous joints are seen. Those
are the mesoscopic structural
features. We found joints in the
Barabkund Section and
Chandranath Hill Section.

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Figure 6.7: Local Unconformity
6.5 Unconformity
An unconformity is a surface of erosion
or non-deposition that generally
separates younger strata from older
ones. Unconformities represent gaps in
the geologic record; periods that are
not represented by any rocks. It is
regarded as a planar structure.
Unconformity is Three types:
1. Angular Unconformity
2. Non-Conformity
3. Dis-Conformity
Also, there is a type of
conformity called Local
Unconformity. Local conformity
remains in many sedimentary
rocks. Maybe in Barabkund
Section and Shahasradhara
Section, there are many local
conformities that are made with
sandstone, Shale, and Siltstone.
But, Unfortunately, we could not
see it.
Local Unconformity

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Chapter Seven
Correlation
7.1 Lithological Description
7.2 Previous Work
7.3 Correlation

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7.1 Lithological Description
Sitakunda Structure is one of the
westernmost structures of the
Chittagong and Chittagong hill tracts. It
is situated in the northwestern part of
the Chittagong district, between
22°34’N and 22°43' N latitude and
91°38' E and 91°41' E longitude. It is
delimited in the north by the Feni river,
in the south by the Karnafuli, in the east
by the Halda river, and in the west by
the Sandwip channel. In a broader
sense, the Sitakunda Hill Range acts as
a water divider between the Halda
valley on the east and the Sandwip
channel on the west. The structure is
about 70 km long and 10-km wide and
is situated at about 270-km southeast
of Dhaka.
The Sitakunda fold is an elongated,
asymmetrical, box-type doubly
plunging anticline. The axis of the fold is
running in the NNW-SSE direction,
parallel to the general trend of the
regional strike. Both the flanks of the
anticline merge into the alluvial plain of
the Feni River in the north and the
Karnafuli in the south due to its doubly
plunging nature.
The structure has a gently dipping
eastern flank and steeper western
flank, which is suddenly truncated by
the alluvial plain. This truncation is a
result of major faulting that runs
parallel to the general strike of the
anticline.
The exposed sedimentary rock
sequences of the structure, except
limestone, provide no difference in
overall lithology from that of other
structures of Chittagong and the
Chittagong Hill Tracts. The Sitakunda
structure contains a thick sedimentary
sequence of sandstone, shale, and
siltstone. The total thickness of the
exposed sediments is about 6,500m.

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7.2 previous study
The Upper Bhuban Member in the
Sitakunda anticline, Chittagong,
Southeastern Bangladesh is constituted
by the light gray, light yellow, and
greenish-gray sandstone and siltstone
with dark gray, bluish-black, and black
finely laminated silty shale to shale. The
lithofacies of massive sandstone(Sm),
turbidite sandstone (ST), flat bedded
sandstone-siltstone (Sh), ripple cross-
laminated sandstone-siltstone (Sr),
laminated sandstone-siltstone (Sl),
lenticular laminated sandstone-
siltstone-shale (Sll), wavy laminated
silty shale to shale (Fw), laminated
shale (Fl) with sub-facies black shale
(Flbk) and blue shale (Flb) and
mudstone (Fm) have been delineated in
this member. Based on genetic aspects
the facies are grouped into (1) turbidity
generated - and (2) deep marine basin
plain facies association. The medium to
fine-grained facies Sm and ST with or
without Sh, Sr, Sl Sll Fw, and Fm facies
constitute the turbidity generated facie
association. The deep marine basin
plain facies association is characterized
by the monotonous hemipelagic bluish-
black shale (surfaces Flb) and pelagic
black shale (surfaces Flbk) with rare to
scare silty stringers of facies Sh, Sr, Sl,
Sll, and Fw. The facies Sm is a turbidity
channel in the inner part of the medial
fan and the complete ST sequence
indicates channelized forms, while
incomplete ones have been identified
as the channel or interchannel deposits
in the medial to the distal fan. The
facies Flb and Flbk denote deep marine
environments above and below the
carbonate compensation depth, where
the lithofacies facies Sh, Sr, Sl, Sll, and
Fw were deposited as distal turbidites.
The facies sequence of medial to distal
fan and deep marine basin plain were
repeated and randomly juxtaposed one
upon other due to instability of basin
probably by faulting along Dauki and
adjoining area accompanied by sea-
level change. The paleo flow pattern
indicates that the dominant source of
detritus was the Shillong plateau along
with a minor contribution from the
Himalayas and Arakan Yoma Folded
Belt. Keywords: Turbidites; Upper
Bhuban Member; Sitakunda anticline;
SE Bangladesh. DOI:
10.3329/jles.v2i2.7491 J. Life Earth Sci.,
Vol. 2(2) 1-16, 2007.

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7.3 Correlation
Age Group Formation Alam et al Roy et al Our study Thickness(m)
Miocene
Surma
group
Boka bil sst+silt
(shale)
Gray to light
gray fine-
grained well-
sorted
sandstone
with sandy
shale and
siltstone.
Lenticular
bedding,
micro cross
lamination,
ripple
marks, and
concretion
are present.
Upper
Middle
Lower
1200
Bhuban Upper
Sst+silt
(shali)
Alteration of
sandstone
silty shale
and shale.
Flat bedding,
ripple
lamination.
Blue to black
laminated
and
exfoliated
wealth red
shale with
massive
mudstone
Upper
Middle
lower
3000+
Table 7.1: Previous work

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Chapter Eight
Discussion & Conclusion
8.1 Discussion
8.2 Conclusion

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8.1 Discussion
Geologically the Sitakund anticline is
an elongated, asymmetrical, box-type
double plunging anticline; which is
the most prominent structure of
Bengal Basin. It is situated in the
Bengal Foredeep portion of the
Bengal Basin, located in the
northwest part of the Chittagong
district. The Sitakund anticline has a
position in the western sub-zone of
the Folded Flank, which is considered
to be the most continuation of the
Chittagong –Tripura folded belt. It
originated from the deformation by
the relative movement of the Indian
plate and Burmese subplate, the
Sitakund anticline is trending in the
NNW-SSE direction.
The western flank has been affected
by a major fault which is indicated not
only by the abrupt change of the
topography but also by some major
irregularities. The field study
included the determination of strike,
dip, and amount of dip. The location
of the station was found and marked
with the corresponding lithology on
the base map.
The sedimentary rocks were mostly
alterations of Shale, Sandstone, and
Silty Shale and were exposed by the
road cutting and erosion by streams.
Based on lithological criteria, there
are two units-
1. Upper sandstone unit
2. Lower shale unit
We found different types of
sedimentary structures like primary
structure; bedding, lamination,
secondary structure; load cast,
groove cast, nodular shale, etc. There
was variation in the thickness of
bedding and lamination, this possibly
indicates different stages of channel
activity. We found many thinly to
thickly laminated shale and silty shale
which can be indicated as a product of
deposition and suspension cloud due
to a decrease in turbulence in current
velocity. We also found a sand lens
that represents the rock in the Surma
group formation. This may also
represent a varied depositional
environment like the fluvial
environment. In some stations, we
found massive sandstone, which may
indicate the rapid deposition of a
large amount of sand from the
fluidized flow. The overall analysis of
lithologic variation of the Sitakund
anticline indicates that the area is
deposited under a shallow marine
environment in the upper
tertiary(Miocene) period. After all,
we observed three days in different
sections, and by plotting the attitude
of beds and lithology we found the
axis on the geological Map.
Although we could not survey many
areas of Sitakund due to our time
limitations, we also couldn’t
recognize some structures due to the
weathering and erosion structures.

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8.2 Conclusion
This whole report is prepared with a
systematic study of some particular
spots in Sitakund Upazila. The total
area that we studied covers about
124-125square kilometers. To
interpret the geologic condition of
any region one has to be sure about
the lithology as well as the structural
features of the certain area. Sitakund
anticline is a huge anticlinorium
containing 4 parallel sets of fault lines
along the NNW-SSE direction. The
structure is likely related to
Himalayan orogeny. The total area
contains regular alteration of
sandstone and shale with a minor
proportion of other special
sedimentary rocks. The main
geomorphic features that we have
observed are the waterfalls, streams,
valleys, cliffs, pools, riffles, etc. It is
predicted that the area is also a
reservoir of petroleum and gas. We
have got evidence by observing the
gas seepage. The first field tour is
essential and effective for a geology
student, which helps him change his
outlook. The first field tour also helps
to think about mother nature and its
processes acting on the earth. The
Sitakund anticline has various
economic values. There is a
significant possibility of getting gas
and oil after hundreds of years.
Because the sediments and bedding
have not yet been so compacted to
drill and mining constructions. It has
been tested by some foreign oil
companies. This field trip was also
very important for our career as a
geologist and we have also enjoyed it
greatly it inspires us to do better and
teaches us to keep our eyes open to
see the history of many billions of
years of our planet, the earth.

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Reference
 https://www.researchgate.net/publication/305048908_2D_Structural_Mo
delling_and_Hydrocarbon_Potentiality_of_the_Sitakund_Structure_Chittago
ng_Tripura_Fold_Belt_Bengal_Basin_Bangladesh
 https://www.researchgate.net/publication/273267295_Turbidities_in_th
e_Upper_Bhuban_Member_of_the_Sitakund_anticline_Chittagong_Southeste
rn_Bangladesh
 https://www.wikipedia.org/
 https://tcktcktck.org/
 A Text Book of Geology by G.B. Mahapatra
 BILLINGS, M.P., 1974: Structural Geology
 Thornbury,W.D. Principles of Geomorphology
 Data from Notebook.
 Google Map
 Bangla pedia

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Geological Map of Sitakund Anticline

Geological Field Report on Sitakund Anticline

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