1

Table of Contents

Introduction ………………………………………………………………… 5

Physiography of the area ....................................................................................... 5

Objectives of Our Field ......................................................................................... 8

Methodology ......................................................................................................... 9

Sedimentary area map ..................................................................................... 10

Igneous-Metamorphic Area Map .................................................................... 11

Tarbela Dam .................................................................................................... 11

Oil well ............................................................................................................ 12

Tectonics and Regional Geology of Hazara Area …………….....… 12

Tectonics ............................................................................................................. 13

Regional Geology ............................................................................................... 14

Stratigraphy and Sedimentation of Harno Area ………………..… 16

Sequence of the Field Area ................................................................................. 16

Hazara Formation ............................................................................................ 16

Datta Formation .............................................................................................. 18

Samana suk Formation .................................................................................... 19

Chichali Formation ......................................................................................... 21

Lumshiwal Formation ..................................................................................... 22

Kawagarh Formation ...................................................................................... 23

Hangu Formation ............................................................................................ 24

Lockhart Limestone ........................................................................................ 25

Patala Formation ............................................................................................. 26

Observation ......................................................................................................... 27

Day 1 (23-08-2013) ......................................................................................... 27

Day 2 (24-08-2013) ......................................................................................... 27

Day 3 (25-08-2013) ......................................................................................... 29

Day 4 (26-08-2013) ......................................................................................... 30

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Day 5 (27-08-13) ............................................................................................. 31

Day 6 (28-08-2013) ......................................................................................... 32

Structures in the Area …………………………………….…………..… 33

Structures in the Area .......................................................................................... 33

Azizabad Fault ................................................................................................ 33

Bohrian Anticline ............................................................................................ 33

Mohar Fault ..................................................................................................... 34

Offshoots of fault along Mohar Nala .............................................................. 35

Unconformities ................................................................................................ 35

Joints, Fractures and Cleavages ...................................................................... 36

Bedding ........................................................................................................... 36

Load Caste and Flute Casts ............................................................................. 36

Other Structures .............................................................................................. 37

Geology of the Recent Deposits ………………………………………. 38

Geology of the Recent Deposits ......................................................................... 39

Conglomerate and Breccia .................................................................................. 42

Clast Stability .................................................................................................. 43

Clast Origin ..................................................................................................... 43

Textural issues ................................................................................................. 44

Imbrication ...................................................................................................... 45

Size, Shape and roundness of clasts ................................................................ 45

Experiment .......................................................................................................... 46

Visit to Oil Well ……………………………………………………...…… 48

Sogri Well No. 1 (N-1) ....................................................................................... 49

Day 7 (29-08-2013) ......................................................................................... 50

Observations .................................................................................................... 50

Drilling Rigs & Working ................................................................................ 52

Rig Components .............................................................................................. 53

Introduction to Well Site Geology ...................................................................... 59

3

Tectonics and Regional Geology of Mansehra and Oghi-Khaki

Area ……………………………………………………………………….… 59

Tectonics ............................................................................................................. 60

Regional Geology ............................................................................................... 61

Geology of Mansehra and Oghi-Khaki Area …………………….… 62

Geology of the Area ............................................................................................ 62

Tanawal Formation ......................................................................................... 63

Marble Facies .................................................................................................. 64

Granites and Gneiss ........................................................................................ 65

The younger granites ....................................................................................... 66

Hackle Tourmaline Granite ............................................................................. 67

Andalusite Granite .......................................................................................... 67

Dolerite Dyke .................................................................................................. 68

Observations ........................................................................................................ 68

Day 8 (30-08-2013) ......................................................................................... 68

Day 9 (31-08-2013) ......................................................................................... 69

Day 10 (01-09-2013) ....................................................................................... 71

Visit to Tarbela Dam ………….………………………………………… 73

Introduction to Dam ............................................................................................ 73

Classification on the basis of Usage: .............................................................. 73

Classification on the basis of Purpose: ........................................................... 73

Classification on the basis of Construction material: ..................................... 73

Classification on the basis of Cross-section: .................................................. 74

Basic Terms Related to Dam .............................................................................. 74

Observations ........................................................................................................ 76

Day 11 (02-09-2013) ....................................................................................... 76

Tarbela Dam ........................................................................................................ 77

History of the Tarbela dam: ............................................................................ 77

Catchment area of the Tarbela Dam ............................................................... 78

4

Major parts of the Tarbela Dam ...................................................................... 78

Geology of the Dam ............................................................................................ 83

Antelope Software........................................................................................... 83

Economic Geology ……………………………..………………………… 85

Economic Geology .............................................................................................. 85

Limestone ........................................................................................................ 85

Laterite ............................................................................................................ 85

Coal ................................................................................................................. 86

Pyrite ............................................................................................................... 87

Fireclay ............................................................................................................ 87

Gemstones ....................................................................................................... 88

Tarbela Dam .................................................................................................... 88

Mining in Hazara ............................................................................................ 88

Oil well ............................................................................................................ 88

5

Introduction The field area was easily accessible by local transport or by own transport facility

and we went there through our university bus. On very first day we travelled from

Lahore to Abbottabad. We did field work in Harno Area (Abbottabad - Nathiagali

Road), Sogri Oil well, Oghi-Khaki Road and Tarbela Dam.

Physiography of the Area Hazara is a region of the Khyber Pakhtunkhwa province of Pakistan. It comprises

six districts: Abbottabad District, Battagram District, Haripur District, Kohistan

District, Mansehra District and now, since 28 January 2011, the new Tor Ghar

District. It is a region that has many languages and ethnicities. Hazara is bounded on the north and east by the Northern Areas and Azad

Kashmir. To the south are the Islamabad Capital Territory and the province of

Punjab, whilst to the west lays the rest of Khyber Pakhtunkhwa. The river Indus

runs through the division in a north-south line, forming much of the western

border of the division. The total area of Hazara is 18,013 km².

Because it lies immediately south of the main Himalaya Range, and is exposed

to moist winds from the Arabian Sea, Hazara is the wettest part of Pakistan At Abbottabad, annual rainfall averages around 1,200 millimeters (47 in) but has

been as high as 1,800 millimeters (71 in), whilst in parts of Mansehra District

such as Balakot the mean annual rainfall is as high as 1,750 millimeters (69 in)

The Indus, Siran, Dor, Harroh & kunhar are the important water resources in

Hazara. Here it is also worth-mentioning that the Indus River, after covering its

course through Kohistan Area, and the River Jhelum, only skirts this division.

The Former runs on the western side of Hazara for 30 miles while the later on the

Eastern side for 25 miles.

The Rivers and streams mentioned above differ from one another in respect of

their origins and discharge flow. The Indus rises about 280 miles away from

Ladakh, while the Siran, Dor & Harroh takes start from Bhogharmang valley.

Dunga Galli (near Nathiagali) and Lalu Sar Lake (Naran Valley) respectively.

Irrigation in this region is possible mainly by the Siran, Dor and Harroh, while

the Kunhar, which joins the River Jhelum at Domail, is so rapid and deep that

utilization of its water for irrigation on a large scale is very difficult.

The above mentioned water bodies have numerous tributaries. Among them some

are perennial while others seasonal.

There are many natural, as well as, manmade lakes in Hazara. These, surrounded

by rocky snowcapped hills are confined to the Kaghan Valley and Haripur

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District. Their names are Lalu Sar, Dudi Pat Sar, Saif ul Malook, Ansoo (Tear)

Tarbela and Khanpur Lake.

Fig. 1.1 Physiography of Harno Area (Peaks and Dor River)

Abbottabad district:

The district covers an area of 1,969 km with the city of Abbottabad. Population

of the area is 4 million.

Topography:

Abbottabad is situated in the Orash Valley lying between 34°09′N latitude and

73°13′E longitude at an altitude of 4,120 feet (1,260 m)

Miranjani (3,313m) and Mukeshpuri are the highest peaks in Nathia Gali in this

district.

Mansehra:

Mansehra is a major stop for tourists on the Karakoram Highway which leads to

China for trade or other interests. It is also a major transit point to the tourists of

northern areas such as the Tehsil Balakot, Batrasi, Atter Shisha, Sireepay Kaghan

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Valley, Naran valley, Shogran valley, Lake Saif-ul- Malook Babusar Top, Ansu

Lake. District covering an area of 5,957 sq. kilometers; it had a population of 2.4

million.

The district of Mansehra has been blessed with wonderful scenery. Some of

Mansehra’s main features are mountain ranges, plains, valleys, and numerous

lakes and rivers.

There are three lakes in the district: Lulusar Lake, Dudipatsar Lake and Saiful

Muluk Lake. All three are located in the beautiful Kaghan Valley and act as a

mirror reflecting the snow-clad mountains surrounding them.

Siran is a largest river in the area of Pakhhal tehsil Mansehra it comes from

mountain Musa Da Masalla (Hindko Word) & falls in Tarbela Dam.

The district consists of three tehsils:

1. Mansehra

2. Balakot

3. Oghi

Following are the main geomorphic features of the area:

Oghi Valley:

Khaki lies 17 km Northwest of Mansehra and from Khaki further Northwest is

Oghi valley.

Mansehra and Oghi (Ogai-

Khaki) Area

Fig. 1.2 Mansehra and Oghi (Ogai-Khaki) Area

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Relief:

Topographic relief is moderate. Slope angle at most places is between 35° to 45°

Drainage system:

The areas is drained by the Siran River and its tributaries which join at Khaki.

It is covered by vegetation and trees which constitute the beauty of the area and

act as natural purifier of atmosphere.

Objectives of Our Field To get the knowledge about basic field skills we use the brunten compass, outcrop

analysis and geological mapping.

To observe different physical features of land and their representation on

topographic sheet.

Find location in the field by toposheet and nearby features.

To identify ubiquitous lithology and Rock type.

Identification of fossils.

Recognition of minerals in their natural form.

Measurement of dip and strike and interpretation of structure of the area.

Relationship between Tectonic, Structure, stratigraphy and

Geomorphology of the area.

Subjects/Aspects to be covered:

Geomorphology

Stratigraphy

Paleontology

Structural Geology

Tectonics

Economic Geology

Engineering Geology

Mapping & Survey

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Methodology The process of conversion of paper maps into digital format by computer is

known as scanning. It is used to convert an analog map into a scanned file which

is again converted to a vector format through tracing.

The Toposheets of the study area was georeferenced in the available format after

scanning and the root mean square error was found. The RMS Error is a measure

of precision and used to determine accuracy of the transformation from one

system to another system of coordinates. RMS Error is measured in pixels. The

standard approach followed anywhere is that while doing georeferencing, Root

Mean Square Error should be less than 1pixel. If the Root Mean Square Error is

more than one, the next step is to convert Latitude and Longitude in Everest

Spheroid projection to UTM projection for the four corners of the Toposheet.

Base map was prepared and it was enlarged 10 times. Enlargement gave us more

detail of the area.

How to locate ourselves in the field

1) Place the map on a smooth surface.

2) Put the brunton on the map and determine the north first, then coincide

the north of the map with the north of the brunton.

3) Then find the matching features on the map and in your surroundings.

For example we located ourselves by matching the Dor River, Nullahs and roads.

Identification of Rocks

Limestones

Sandstones

Shales

Concept of brunton compass with dip and strike

Dip: It is the angle of inclination of rock.

Strike: It is attitude of rock and it shows the direction of extension of rock.

Brunton/clinometers: Instrument used to measure the dip and strike of the

rock or any plane.

Components of Brunton:

a) Compass needle

b) Bull’s eye

c) Cylinder bubble

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Compass needle is used to find the direction with respect to north. Bull’s eye is

used to measure the strike when its bubble is in the center while cylinder bubble

is used to measure the dip keeping the bubble at center.

Strike value is represented as N45˚E while dip value is represented as NE45˚.

Sedimentary area map Base Map:

Map which shows the basic informations about the natural and man-made

features of the area. (Map attached)

Topographic Map:

Map which shows the size shape and distribution of natural features (landforms)

and man-made features (Map attached)

Field area Map:

Title:

Geological Map of the Harno Area Abbottabad

Area:

Harno Area Abbottabad Part of Toposheet No. 43F/8

Scale:

The area mapped on scale of 1cm: 100m

Legends:

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Reference/ Datum:

Elevation of the area is according to Arabian Sea Level

Grid Reference:

Study area of our field work lies between:

Longitude: 73° 17' 00" to 73° 20' 40" E

Latitude: 34° 08' 37" to 34° 10' 00" N

Igneous-Metamorphic Area Map The area near the town of Susalgali along the Oghi-Khaki and is regionally

metamorphosed. The area is easily accessible form Abbottabad youth hostel

through Mansehra by Oghi-Khaki road.

Title:

The area is covered by toposheet no. 43F/3 under the title of “Geological Map of

Mansehra and Khaki Oghi road section”.

Scale:

Scale of the map is 1 inch to 2.394 miles while R.F is 1:25,000.

Grid Reference:

The concerned area lies between:

Latitude: 34° 25' 00" to 34° 26' 00" N

Longitude: 73° 3' 00" to 73° 8'00" E

Tarbela Dam Tarbela Dam on the Indus River in Pakistan is the largest earth filled dam in the

world and second largest by structural volume. The dam is 485 feet (148 m) high

above the riverbed. The dam forms the Tarbela Reservoir, with a surface area of

approximately 250-square-kilometre (97 sq mi). The dam was completed in 1974

and was designed to store water from the Indus River for irrigation, flood control,

and the generation of hydroelectric power.

Catchment area of the reservoir created by the dam is 169,600 square kilometers.

The reservoir, with a maximum depth of more than 450ft, can impound up to

12

11.62 million acre foot (MAF) of water at the maximum lake elevation of 1,550ft.

Net usable capacity of the reservoir is 9.68MAF.

Oil well Sogri Well (N-1) is located near Jhalar having coordinates 33° 29 ́ 44.09 ̋ N

72° 06 ́ 38.30 ̋ E, Oil & Gas development Company Limited, Pakistan (OGDCL)

is drilling for oil.

The structure formed in the subsurface of SOGRI well is pop up anticlinal

structure which is formed due to the thrust faults and back thrust whiles the

formation of backthrust occurred during foreland propagation. Foreland

propagation occurred in fold and thrust belt and is due to thin skinned crustal

shortening. Backthrust can also be defined as thrust sheets that are directed back

in the opposite direction of foreland propagation.

Murree formation and Kohat Formation are present as an imbricate structure

and repeat thrice in the subsurface below which chorgali formation and sakesar

Formation are present.

Patala Formation acts as a Source Rock.

Murree Formation acts as a cap rock.

Lockhart Limestone, Chorgali formation and Sakesar Limestone acts as a

reservoir.

----------- Detail about field observations and identifications are given in

following chapters and associated sketches and figures are drawn.

13

Hazara Area

Tectonics The active fold – and – thrust belt along the northwestern margin of the Indo –

Pakistan plate is divisible into two parts – the Sulaiman belt and the NW

Himalayan fold and thrust belt. The former is believed to be along a zone of

transpression, whereas the latter is associated with the main zone of Himalayan

convergence (Jadoon, 1992). The compressional forces being experienced in the

NW Himalayan fold and thrust belt are believed to be a result of the ongoing

collision of the Eurasian and Indo- Pakistan plates that took place in the late

Eocene to Early Oligocene. The Indo- Pakistan plate, relative to the Eurasian plate

is still moving northwards at a rate of about 2 mm/yr (Patriat and Achache, 1984).

In 1981, Gansar classified Himalayas from south to north as:

MFT (Main frontal Thrust) to MBT (Main Boundary Thrust) as Sub-Himalayas

MBT (Main Boundary Thrust) to MCT (Main Central Thrust) as Lesser-

Himalayas

MCT (Main Central Thrust) to MMT (Main Mantle Thrust) as Higher-Himalayas

The southeast Hazara, being very close to the MBT (to the north of MBT), has

undergone intense deformation. In the study area this deformation is marked by

southeast verging thrust faults, and northeast trending anticlines. This northeast

orientation of the major structures suggests that the area has been under the

influence of northwest-southeast oriented stresses.

The hinge lines of most of the folds in the study area are found to be northeast-

southwest trending which also suggests that the area is subjected to northwest-

southeast compressive stresses.

The style and deformation in the western limb of Hazara Kashmir Syntaxis differs

from that of the eastern limb. The Salt Range Formation acts as a decollement

under the western limb of Hazara Kashmir Syntaxis and is absent under the

eastern limb.

Due to the presence of Salt Range Formation, the Hazara thrust system has low

angle faults and low topography. The angle of these thrust faults gradually

increases from SW to NE where the thickness of Salt Range Formation decreases.

In the eastern limb of the Hazara Kashrnir Syntaxis the absence of Salt Range

Formation developed the high angle thrust faults (MBT and PT) and high

14

topography. There is strong coupling between sediments and basement as

compared to the western limb of the Syntaxis.

Due to the collision between Indian and Eurasian plates crystalline basement has

been overridden by slices of its own northern margin. The SSE stresses on the

western limb and SSW stresses on the eastern limb developed the thin-skin thrust

faults in the sedimentary wedge. These thrust sheets have brought in contact the

different lithological units.

Fig. 2.1 Study area map

Regional Geology Situated W of the North-West-Himalaya Syntaxis (WADIA, 1931), Hazara is in

the neighborhood of the Salt Range, Kashmir, and of the Lower Himalayas of the

region SE of the syntaxis. This seems to be responsible for its unique sedimentary

development. It is well-known that the succession of the Lower Himalayas is very

poor in fossils, in contrast to the wealth of the paleontological record in the

Tibetan Zone, N of the Great Himalayan Range. Therefore it is concluded that

15

the trough of the Lower Himalayas was separated from the sea by a ridge (G.

FUCHS, 1967).

Hazara Area is part of Attock Hazara Fold and Thrust belt which is northern part

of Pakistan and located on border of India & Pakistan. It has Assam in the east

and Nanga Parbat in the west.

Overall, it is western most part of Himalayas in the world but NW Himalayas in

Pakistan. They include Kashmir basin and Kaghan valley. This region was

formally named as Punjal Himalayas or Foreland basin in 1964 by Gansar. Indus

River is located in its NW direction and Sutluj is located in the east.

If we follow Murree-Abbottabad Road, it divides Hazara into two synclines:

1- Nawansher Syncline

2- Kuzagali Syncline

General trend of these synclines is NE-SW. It is bounded by Punjal Thrust in

north and Murree Fault in south.

Our study area is Nawansher syncline.

16

Stratigraphy and Sedimentation

Sequence of the Field Area

Patala Formation

Lockhart Limestone

Hangu Formation

Kawagarh Formation

Lumshiwal Formation

Chichali Formation

Samana suk formation

Datta Formation

Hazara Formation

Hazara Formation Hazara Formation was observed at the right bank of Azizabad Nala. General trend

of the Formation is NE-SW. This unit is brownish to brownish grey and greenish

grey on fresh surface and dark brown or rusty greyish brown on weathered

surface. Rock mainly comprises of slates, siltstone, claystone, quartzite and

oblique sandstone. Slates are highly jointed and generally form debris with

splintery nature. Siltstone is somewhat lighter in color than in clayey parts.

Claystone is more thinly bedded ranging from 1cm to 2.5cm layers from thin upto

thick beds. Fine grained to medium grained greywacke is also observed. It is dark

grey to black on fresh surface and light grey or brownish grey on weathered

surface. There thickness varies from 10 to 20cm. Ripple marks, Load casts and

flute casts were also observed in fine sand and siltstone.

Upper contact with Jurassic Datta Formation which is faulted contact.

Depositional Environment varies from shallow marine to marginal and then deep

marine environment.

Age of the formation is given 765±20 to 950±20 m.a on the basis of radiometric

dating (Rb/Sr method). Mir Latif gave the age Paleozoic on the basis of some

fossils recorded.

17

Fig. 3.1 Outcrop of Hazara Formation

Fig. 3.2 Sole marks in Hazara Formation

18

Datta Formation Datta Formation has limited exposure 1.5m thick. One outcrop of Datta

Formation is 1.5m thick was recorded along right bank of Azizabad Nala.

Datta Formation is hard, tough quartzose and ferruginous sandstone. It passes

through back of houses and terminates upstream side of Nala and even in whole

study area. General trend of the formation is NE-SW.

Datta Formation is mainly sandstone, it is brownish, reddish brown and dark grey

on fresh surface as well as on weathered surface. Beds are 30 to 40cm thick. Grain

size is medium to coarse, well cemented, tough to hammer.

Lower contact with Hazara Formation is unconformable. Upper contact with

Samana suk Formation is sharp.

Age of the formation is Early Jurassic.

Fig. 3.3 Outcrop of Datta Formation

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Samana suk Formation Formation was observed from Abbottabad to Nathiagali road section, 1 km from

Harno and 200 m from Azizabad (Azizbang).

Medium grey to dark grey on fresh surface. Yellowish grey to light grey on

weathered surface. Even on some patches some black spots are present.

Formation is thin to medium and well bedded.

Thickness ranges from 10 cm to 24 cm. It shows well developed joints and

fractures, joints are almost perpendicular to bedding.

Limestone shows dolomitic patches in many parts however it is absent in places.

Oolites are either not developed or is difficult to identify whoever at some places

very well developed are also present. Thin irregular 1mm to 2mm calcite veins

are developed in Formation.

Limestone is affected by solution weathering. Low amplitude (1cm to 2cm)

stylolites are well developed along the bedding.

Three parts division of Formation was observed in the field area:

In basal parts, it overlies Datta Formation in Hazara area. It is nodular, highly

fossiliferous with both micro and mega fossils. Sandy bed of Samana suk

Formation (lower bed 1.5m) longly mistaken as Datta Formation.

Middle to upper part of Samana suk Formation is medium grained and well

dolomitize with laterite.

Upper contact with Chichali Formation may be sandy dolomite.

Samana suk Formation shows competent cliff forming lithology. Lower contact

may be sharp contact with Datta formation. Hard Ground development in Samana

suk Formation was observed.

Fossils like ammonites, gastropods and brachiopods are present. The age of the

Formation is upper Jurassic.

20

Fig. 3.4 S Type fold in Samana suk Formation

Fig. 3.5 Hard ground development in Saman suk Formation

21

Chichali Formation Generally soft lithology, thinly laminated calcareous black shale interbedded with

thin sandstone. General trend is NE-SW.

Dark grey to brownish black on fresh surface and brownish yellow to black on

weathered surface. The shale is splintery, flacky and blocky with 2cm to 6cm

thick beds of light grey to brownish sandstone. It weathers to yellowish brown to

brownish grey. Ferruginous concretions & coating such as dense silver grey and

pyritic nodules with golden or rusty brown are recorded within the shale. At

places rounded or elliptical variegated colored clay nodules or concretions are

also recorded. At few places the color of Chichali Formation becomes brownish

grey and confused to be Patala Formation whoever the presence of Belemnites

and imprints of Belemnites confirm it Chichali Formation. The veins of calcite

generally cut through the rock. Rock is generally incompetent and soft. The shale

of Chichali Formation squeezed and eroded and forms valley and topographic

depressions. The continual mixing of Coal is carried out in Chichali Formation in

the field area.

Lower contact with Samana Suk Formation is sharp and generally shaley part of

Formation whoever upper contact with Lumshiwal Formation is gradational with

the Lumshiwal Formation due to presence of Belemnites and Ammonites. The

age of the Formation is late Jurassic.

Fig. 3.6 Outcrop of Chichali Formation

22

Lumshiwal Formation Formation mainly composed of medium to coarse grained sandstone with

intercalations of shale. It has only fainted exposure in the study area that is

recorded at number of places associated with Chichali Formation. General trend

is NE-SW.

The Lumshiwal Formation is brownish grey on fresh surface and weathers

yellowish brown color sandstone (medium to coarse grained). At places

sandstone retains some angular to dark grey to blackish apparently siliceous

fragments in the upper parts. Sandstone of this formation shows brownish grey

very hard quartzite behavior with yellow patches. This quarts is overall 6cm to

10cm thick.

In the upper part 20 to 40cm thick intraformational conglomerates along with

broken shells and incomplete Belemnites are also present and some of these

fossils have been removed completely or incompletely with calcite. Below this

14 to 16cm thick shales are also recorded. Shale is purplish grey, pale and maroon

in color.

Sandstone of Lumshiwal Formation is very hard and resistant to weathering.

Large boulders are also recorded along downhill and newly built road.

Lower contact with Chichali Formation is gradational and transitional. Upper

contact with Kawagarh Formation is sharp.

The age of the formation is early Cretaceous.

Fig. 3.7 Outcrop of Lumshiwal Formation

23

Kawagarh Formation

Kawagarh Formation is observed in locality Sarbhana at left bank of Harno Nala.

Kawagarh Formation comprises fine grain creamish grey yellowish grey well

bedded Limestone.

Light medium grey to light yellowish grey on fresh surface. A fresh color also

imparts with off white or light grey or brownish grey. Limestone is light yellowish

grey to whitish grey on weathered surface.

Limestone is generally fine grained, medium grained also recorded at some

places. Thickness ranges from 30 to 60 cm.

It is tough & hard to hammer and break with conchoidal fractures whoever some

beds break with irregular fractures. Intercalations of shale are also present. Calcite

veins abundant in some parts. Limestone is dolomitize at places and calcite is

dolomitize in few patches. Formation is divided into three parts:

- Fine grain material

- Whitish maroon color limestone

- Thin intercalated shale

Micro ridges due to solutioning are also present. Dolomitize part of Kawagarh

Limestone shows characteristics of dolomite e.g. chop board weathering.

Fig. 3.8 Intraformational fault in Kawagarh Formation

24

Hangu Formation Hangu Formation is exposed in the form of thin band and relatively with highly

weathered exposure at many places in the field area. It is mainly comprises of

sandstone, clays, laterite, limestone and carbonaceous material. Sandstone part is

medium to coarse grained and very hard, whitish grey on fresh surface and

maroonish brown on weathered surface.

Fireclay is grey, whitish grey on fresh surface and weathered in variegated colors

as yellow and red. Laterite part is red to maroonish yellow.

Limestone is sandy 0.5 to 0.7m.

Carbonaceous horizon is black to dark grey.

The formation is missing and is being incompetent, crushed, over and underlying

limestone and is replaced by conglomerate beds (1 to 3m thick) and compacted

layer of conglomeritic nodules (2.6cm). Nodules are composed of Limestone

cemented with calcite. Shape of nodules is rounded to well rounded. They show

poorly sorted and mark an unconformity.

Age of the formation is Early Paleocene.

Fig. 3.9 Outcrop of Hangu Formation

25

Lockhart Limestone Outcrop was observed 100m of left bank of Harno Nala (opposite bridge on Dor

River). General trend of the Formation is NE-SW.

Lockhart Limestone is generally dark grey to medium grey hard nodular

limestone. Lockhart Limestone is dark grey on fresh surface. Limestone is bluish

grey to light colored on weathered surface whoever calcite veins are present in

Lockhart Limestone. On weathered surface Limestone is off white or pale colored

fine to coarse grained. Limestone is hard & tough and gives fetid smell (rotten

egg). Bedding is massive but not clear.

Nodules are present which are 3 to 5 cm in diameter composed of hard Limestone

while surrounded material is calcareous relatively soft and abundant in fossils.

Irregular fractures and abundant forams of 2 to 3 mm size are present. Calcite

veins are frequent and generally 1 to 2cm thick.

Lower bed is in contact with Hangu formation is arenaceous.

Formation was given the age Paleocene due to the presence of fossil Lockhartia

and broken shells.

Fig. 3.10 Lokhartia in Lokhart Limestone

26

Patala Formation Outcrop of Patala Formation was regarded at left side of road from Abbottabad

to Mohar. Lower part is composed of alternate marly limestone and shale beds

predominantly. Middle part is shale with thin beds of Limestone. Upper part is

sandy marly limestone and shale.

Shale of fine to medium grained with thinly interbedded claystone and siltstone

beds are present. Shale is greenish grey and light brown on weathered surface and

light brown to light grey and greenish grey on fresh surface.

Shale is splintery at places interbedded with claystone near contact with Lockhart

Limestone. Shaley beds are soft, friable and generally make flat area along the

road to Mohar. It also shows cleavage at places and numerous fractures. Rock is

very fine grained and generally generates angular debris. Blacky marl beds are

thinner and at places show range of thickness from 1 to 5cm.

Lower contact with Lockhart Limestone is gradational.

Age of the formation is middle to late Paleocene (Patalensis).

Fig. 3.11 Outcrop of Patala Formation

27

Observation

Day 1 (23-08-2013) Travel from Lahore to Abbottabad. The base camp was Youth Hostel Abbottabad.

The field party comprises of 51 members including students, teachers and

workers. Different teams from students were structured including mess team, first

aid team, and residential team for better and quick performance in the field. A

lecture was organized to brief about the field area and methodology. Students

were divide into different groups, each group consisting of four members and

base map was given to all the group members. A brief about the GPS use was

delivered by our teachers.

Day 2 (24-08-2013) We observed the following sequence and contacts on the right side of the Dor

River:

Patala Formation

Lockhart Limestone

Hangu Formation

Kawagarh Formation

Lumshiwal Formation

Chichali Formation

Samana suk Formation

Hazara Formation

Fig. 3.12

Azizabad Fault

between Hazara

Formation and

Samana suk

Formation

28

Fig. 3.13 Contact between Chichali Formation and Lumshiwal Formation,

Lumshiwal Formation and Kawagarh Formation

29

The same sequence was observed on the left side of the Dor River. Datta

Formation was uncertain till this time, which was observed on next day dated 25-

08-2013.

Day 3 (25-08-2013) The following sequence and contacts were observed:

Lockhart Limestone

Kawagarh Formation

Samana Suk Formation

Datta Formation

Hazara Formation

Fig. 3.14 Outcrop of Datta Formation

Outcrop of Datta Formation was also observed by field party. Offshoots of Mohar

fault was observed there.

Sedimentary structures like flute cast and load cast were recorded in hazara

Formation.

30

Day 4 (26-08-2013) The following sequence and contacts were observed:

Patala Formation

Lockhart Limestone

Hangu formation

Kawagarh formation

Lumshiwal Formation

Chichali Formation

Samana suk Formation

Fig. 3.15 Contact between Chichali Formation and Lumshiwal Formation

We observed Bohrian anticline, Mohar-Khurd fault and KT boundary between

Kawagarh Formation and Hangu Formation.

31

Day 5 (27-08-13) The following sequence and contacts were observed:

Patala formation

Lockhart Limeston

Hangu Formation

Kawagarh Formation

Lumshiwal Formation

Chichali Formation

Samana suk Formation

Fig. 3.16 Contacts of Kawagarh Formation, Hangu Formation, Lockhart

Limestone and Patala Formation

32

Day 6 (28-08-2013) The following sequence and contacts were observed:

Patala Formation

Lockhart Formation

Hangu Formation

Kawagarh Formation

We also observed different units of Hangu Formation and pyrite nodules.

Fig. 3.16 Contacts of Kawagarh Formation, Hangu Formation and Lockhart

Limestone

33

Structures in the Area Azizabad Fault Azizabad fault is present between Hazara Formation of Pre-cambrian and Samana

Suk Formation of Jurassic age. It is major fault of the area. Slates (Hazara

Formation) are highly jointed and generally form debris with splintery nature.

Sketch 4.1

Bohrian Anticline While sitting at the roadside towards Mohar village, Borian anticline can be seen

under the Borian village which is located on its hinge area. It is an open tight

structure whose fold axis trending SW and plunging NE. Its core is formed of

Samana Suk Formation which shows steep eastward dipping on its SE flank

where it is being querried at the mouth of Nala.

Samana Suk Formation of the core is flanked by Chichali Formation and

Lumshiwal Formation on both sides. These are exposed above Borian village as

well as Mohar village. So, outcrop of Chichali Formation and Lumshiwal

Formation is thin and disturbed near querry. Further outwards occur Kawagarh

Formation which has a wide outcrop on gentler NW limb which has been largely

34

truncated by a fault on SE limb. Here it shows thin outcrop between querry and

road.

The anticline is Asymmetric with axial plane dipping NW.

Development of Lapies in the limestone of Kawagarh Formation in the sloping

area Lapies are the landforms produced by solutioning in which harder parts of

limestone left as imprints.

Fig. 4.1 Panoroma view of Bohrian Anticline

Mohar Fault Mohar Fault is present between Samana Suk Formation and Chichali Formation

Chichali Formation is present in the Mohar Nala and fault is along the fault.

35

Sketch 4.2

Offshoots of fault along Mohar Nala

Sketch 4.3

Unconformities Two unconformities were found in the field area.

Unconformity 1

One is present between Hazara Formation of Pre-Cambrian and Jurassic Datta

Formation. The age gap (hiatus) between these two formations marks the

36

uncomformity in the area. Datta Formation is also recorded in the upstream area

having only outcrop of 1.5 meters and it was absent from the downstream side of

the field area.

Unconformity 2

Second Uncomformity was found between Kawagarh Formation and Hangu

Formation also called KT boundary. Hangu Formation was exposed first which

show break in deposition and meanwhile erosion started. Intraformational

conglomerates (rounded to subrounded and elongated) are also found in the area

which marks the break in deposition.

Joints, Fractures and Cleavages Patala Formation shows cleavage at places and numerous fractures.

Well-developed joints and fractures were observed in Samana Suk Formation

joints are perpendicular to bedding.

Fractured Limestone of Lockhart Limestone (induced and irregular fractures at

some places)

Concoidal fractures in Kawagarh Limestone however at some places irregular

fractures

Hazara Slates are highly jointed and generally form debris with splintery nature.

Bedding Kawagarh Limestone is well bedded. Its thickness ranges from 30 to 60 cm.

Massive bedding in Lockhart Limestone but not clear.

Saman Suk Formation is thin to medium and well bedded. Thickness ranges from

10 cm to 24 cm.

Beds of Datta Formation are 30 to 40cm thick.

Load Caste and Flute Casts Load Caste and Flute Casts In fine sand and siltstone of Hazara Formation.

37

Fig. 4.2 Sole marks in Hazara Formation

Other Structures Size of nodules in Lockhart Limestone is 3-5 cm and composed of hard

Limestone. In Lockhart Limestone calcite veins are abundant and 1mm to 2 cm

thick. Small scale ripple marks in fine sand and siltstone of Hazara Formation. In

Kawagarh Formation calcite veins are abundant at some places and dolomitized.

Thin irregular 1mm to 2mm calcite veins are developed in Saman Suk Formation.

Micro ridges due to solutioning are also present. Kerran structure was also

observed. Dolomitize part of Kawagarh Limestone shows characteristics of

dolomite e.g. chop board weathering.

38

Fig. 4.3 Kerran Structure

39

Geology of the Recent Deposits Fluvial deposit is composed of river system and recent deposits are almost

deposited alongside of nallas. Dor River is the local base level in the field area,

we started from Azizabad Nala (Azizband) then passed through Harno and

Sarbhana.

Most terraces are deposited along nallas and road sides, they may show nearly

vertical faces besides nallas but most show stratification either poorly or well

developed.

Terrace/Fluvial deposits were recorded at the junction of Harno Nala to Dor River

near the Harno bazar. Stratified fluvial deposits of 25m thick and 300m long was

recorded.

General grain size from gravel, pebble, cobble and some boulders upto 6cm in

diameter were recorded in the area. These deposits are loosely packed in fine

grained sand size and coarse grained sand to gravel size material acting as matrix.

At least four fining upward cycles were recorded having cobble to pebble size

material at base and coarse to very coarse gravel on the top. Base shows scoops

or erosional wavy contact. Lower facies of large scale conglomerates 30cm thick

having trough cross bedding (4 to 5 feet in length and 1 to 2 feet in height).

Shape of coarser material is rounded to sub rounded and fine grain material is

angular to sub rounded. Low angle planar cross bedding on middle surface of

each cycle was also recorded. Overall these deposits show deformation and low

angle vertical faults at least two or three places and folding at several places.

Generally these deposits are gravely-ferrous however at some places fine material

from fine silt to sand is also present, which shows a distinctive and non-uniform

nature. At places they may be lenticular, on the other hand it also shows graded

bedding.

Coarser material:

Mostly developed in channels. When this coarser material is present in Dor

River, it shows breaded stream behavior.

Fine material:

Finer material shows stages of flood (high rain fall).

Generally fine material shows decreasing in velocity (suspension).

40

Fig. 5.1 Cyclic deposition in fluvial deposts

Size of the material shows competency of flow between Dor River and associated

nallas. This competency is associated with:

Flow of water

Gradient

Shape of the channel

When we go from Azizabad to Mohar, some of these deposits are high more than

100m from the present day river bed. This may be because of:

They join river from 100m above the bed or

Some tectonic up thrown.

These deposits are not tectonically disturbed because they don’t have major

folding and faulting.

Source of these deposits are slates, dolomite, shale, limestone, siltstone etc.

Degree of roundness indicates amount of transportation however some show

weathering and relief area.

41

We also found colluvial material which show deficiency of stratification, poorly

sorting and more angularity.

River became wider depending upon conference and lithology of Nala. Valley

flow was much wider at the time of deposition. After the deposition of these

deposits, river started down cutting and leaving their own flood plain.

Fig. 5.2 Contact between recent alluvium and Patala Formation

42

Conglomerate and Breccia

Lithified gravel (rounded) and rubble (angular) are called conglomerate and

breccia, respectively.

Conglomerates are very special in the sedimentary record for two reasons:

They are always associated with high energy systems.

They more often preserve properties of bulk source rock, in addition to the

minerals of which it consisted.

As such, they are very helpful in reconstructing provenance of the hinterland, as

they consist of sediments that generally have not been transported far and are

often linked to nearby tectonic activity.

Together these comprise 1 - 2% of sedimentary rocks.

Parameters of conglomerate composition

Grain size:

Conglomerates (and breccias) typically display two grain size classes:

1) Framework:

Large clasts, diameter >2mm

2) Matrix:

Smaller clasts filling in the gaps between framework clasts

Compositionally we distinguish:

Mineral components:

- Fragments consisting of single mineral crystals

- Usually in low abundance

- Most common are quartz and feldspars

Less common are micas, olivine, pyroxene, amphibole, and others

Rock fragments:

Multigrain fragments of whole rock.

More abundant Can be any rock type and provide info on provenance.

43

Clast Stability

Oligomict

>90% of framework clasts consist of resistant rocks and minerals.

e.g. Quartz, quartzite, chert

Implies that sediment underwent intense chemical weathering prior to

deposition, leaving only the most durable weathering products

Petromict

Clasts of metastable and unstable rocks and minerals are abundant.

e.g. Basalt, slate, limestone

Clast Origin

Finally, we distinguish clasts depending on their origin as

Intraformational:

Clasts are eroded from the same sedimentary rock unit of which they are a

part.

Framework and matrix composition are the same.

Extraformational

Clasts are derived from source areas outside the depositional basin.

Framework and matrix composition differ.

Using this information, we can begin to classify conglomerates according the

classification scheme.

When clasts are extraformational, we have two general categories:

Orthoconglomerate

Consist primarily of framework grains and <15% matrix.

The framework is grain-supported (i.e. the framework grains contact and support

one another).

44

Orthoconglomerates can be further classified as

o Oligomict orthoconglomerates

o Petromict orthoconglomerates

Paraconglomerates

Have a matrix of sand and finer clasts and are matrix-supported.

Paraconglomerates are further broken down based on the internal structure of

the matrix:

Laminated conglomeratic mudrock

If matrix is laminated. Laminations imply that the framework clasts were dropped

into preexisting laminated deposits of the matrix material as dropstones.

Unlaminated matrices

Imply two possible origins:

o Tillite

- Glacially transported sediment

- Poorly sorted sediment

o Tilloid

- Sediment transported by sub aerial or subaqueous debris

flows

- Turbidity currents, and subaqueous grain flows.

Textural issues

Sorting and modality:

Conglomerates are very poorly sorted. We see two general classes:

Bimodal

2 dominant clast sizes

Typical of orthoconglomerates and sediments deposited by rivers.

45

Polymodal

> 2 dominant clast sizes.

Typical of paraconglomerates and sediments deposited by glaciers, mass

wasting, or turbidity currents

Imbrication

The systematic orientation of clasts in a conglomerate is termed imbrication. This

usually indicates stream or glacier transport in which grains are aligned with

current.

Still confused about the agent of transport for your conglomerate? Look for hints

such as sedimentary structures, or the texture of clasts. Basal flute casts indicate

turbidity current. Parallel striations of clasts (right) suggests they came in contact

with a glacier.

Note: Diamictite is another term for a paraconglomerate, and is often used to

denote glacial rocks.

Size, Shape and roundness of clasts

Size, Shape and roundness of the coarse clasts are measured in the field. It was

easy to measure the size of clasts because the beds were not cemented

andlithified. For rounded clasts we measured the diameter and for those which

are not rounded we measured the long (a) intermediate (b) and short (c) axis of

the clasts measured along three mutually perpendicular lines. We determine the

maximum particle size.

46

Experiment

Fig. 5.3 Conglomeritic bed of fluvial deposits

Dataset acquired from field is given as:

Sr. no Maximum Particle Size(MPs)

(cm)

1 11

2 7

3 4.2

4 3.5

5 3.5

6 3

7 2

8 2

47

9 2.6

10 3

11 2

12 2

13 1.5

14 2

15 3

16 1.5

17 1.3

18 3

19 2

20 2.5

21 3.2

22 2.5

23 2.5

24 2.5

25 4

26 5

27 2

28 3.6

29 3.5

30 2

31 3

32 4

33 2.5

34 3.5

35 4.5

36 4.5

37 3

38 2.5

39 2.5

40 4

41 2

42 5

43 4.5

44 8

45 2

46 2.5

47 1

48 2.5

49 4.5

48

Total = 49

Sedimentary Rock fragments = 33

Igneous Rock fragments = 1

Metamorphic Rock fragments = 15

%age Sedimentary Rock fragments = 67.347%

%age Igneous Rock fragments = 2.0408%

%age Metamorphic Rock fragments = 30.61%

Result: Provenance (source) of these recent deposits (conglomerates) is

sedimentary.

49

Sogri Well No. 1 (N-1)

Oil & Gas development Company Limited, Pakistan.

Spud on: 15-04-2013

T.D: 4950m

Rig: N-1

Unit: D.L.2

50

Day 7 (29-08-2013)

Observations The entire class was divided into three groups led by the workers of the OGDCL.

We visited different parts of the oil rig one by one in which our group first visited

the Mud pumping unit.

In the mud pumping unit there were five tanks of the drilling fluid in which three

were active and two tanks was kept as a reservoir. This mud goes inside the well

through drill pipe and its main function is to cool down the bit which are been

used for cutting and then to take the cuttings with itself towards the surface into

the shale shaker through which observe the composition of material in the

subsurface.

Secondly our group visited the Rig floor portion and its was supervised by a

chemical engineer in which we observe working of Rig and the operation of the

draw works attached to the engines and its main function is to provide power to

the rig.

In the last we visited the data logging unit where the geologists briefed us about

the mud ratio and the cuttings from the subsurface in the digital format.

GPS/Coordinates of the Well Site:

33° 29 ́ 44.09 ̋ N

72° 06 ́ 38.30 ̋ E

Total Depth: 4950m

Depth Drilled: 2398m

Diameter of Hole: 17.5 inches

Source Rock: Patala Formation

Reservoir Rock: Lockhart Limestone (primary)

Chorgali Formation (secondary)

Cap Rock: Murree Formation

51

Sequence of the Well

Murree Formation

Kohat Formation

Murree Formation

Kohat Formation

Murree Formation

Kohat Formation

Kuldana Formation

Kohat Formation

Chorgali Formation

Sakesar Limestone

Nammal Formation

Patala Formation

Lockhart Limestone

Sub-surface Structure

The structure formed in the subsurface of SOGRI well is pop up anticlinal

structure which is formed due to the thrust faults and back thrust whiles the

formation of backthrust occurred during foreland propagation. Foreland

propagation occurred in fold and thrust belt and is due to thin skinned crustal

shortening. Backthrust can also be defined as thrust sheets that are directed back

in the opposite direction of foreland propagation.

Murree formation and Kohat Formation are present as an imbricate structure

and repeat thrice in the subsurface below which chorgali formation and sakesar

Formation are present.

Patala Formation acts as a Source Rock.

Murree Formation acts as a caprock.

52

Lockhart Limestone, Chorgali formation and Sakesar Limestone acts as a

reservoir.

Drilling Rigs & Working

The drilling process is a very in-depth process. A well site must first be selected

then all the legal documents obtained. Drilling operations can begin only after the

site has been prepared, ground has been leveled, roads have been built, a derrick

has been erected, and other equipment that comprises the drill rig has been put in

place. Water is a vital component in the drilling process for mixing drilling mud

(lubricant). Water can be hauled into the location by trucks or pumped from a

nearby lake, pond, or water well. If no source is available, a new water well must

be drilled before the drilling process can begin.

The most common drill rigs are of the rotary rig type. Today's rotary drill rig

consists of multiple engines that supply power, hoisting equipment that raises and

lowers the drill string (drill pipe), and rotating equipment that turns the drill string

and the drill bit. These engines also drive the circulating equipment that pumps

liquids (mud) down the hole to lubricate the drill string and drill bit which are

rotating in the hole. These liquids remove cuttings (loose bits of rock), and

controls down hole pressure to prevent blowouts (unexpected pressure, which

overcomes the weight of the drilling mud and explodes to the surface).

The conventional drill bit has three movable cones containing teeth made of

tungsten carbide steel and sometimes industrial diamonds. The rotating cones are

the cutting heads. The downward force on the drill bit is the result of the weight

of the overhead drill stem (steel pipe, pipe joints called collars) and drilling

equipment on the derrick all of which can amount to thousands of pounds. Keep

in mind that the entire pipe and bit assembly rotate together in the hole.

While the bit cuts the rock at the bottom of the hole, surface pumps are forcing

drilling fluids down the hole through the inside of the drill pipe and out the bit.

This fluid lubricates and removes cuttings. The fluid (with the cuttings) then

flows out the center of the drill bit and is forced back up the outside of the drill

pipe onto the surface of the ground where it is cleaned of debris and pumped back

down the hole. This is an endless cycle that is maintained as long as the drill bit

is turning in the hole. The drilling crew is under the supervision of the Driller.

The person who works on a platform high in the derrick is called a Derrickman;

he has the very dangerous job of handling the upper part of the drill stem as it is

raised and lowered. Roughnecks are the workers on the derrick floor; their job is

to add new pipe joints as the well depth increases. The entire crew and operation

of the rig is under the supervision of the Tool Pusher. A typical drill rig will

operate 24 hours per day, 7 days per week. It never shuts down for holidays.

53

A drilling operation produces waste material that includes drilling mud, rock

cuttings, and salt water brine (highly concentrated salt water) which flows out of

a reservoir trap and up the well to the surface. These materials must be disposed

of properly. The reserve pond is often dug to temporarily hold the brine and

drilling mud. Neither the drill mud nor the salt water brine is allowed to remain

at the drilling site. All waste materials must be removed off site and sent to a

properly licensed landfill for disposal.

Rig Components

Water Table:

The water table is the walk-around at the top of standard derricks which supports

the crown block.

Crown Block:

A series of sheaves affixed in the top of the derrick used to change the direction

of pull from the drawworks to the traveling block.

Derrick:

Vertical structure that allows vertical clearance and strength to raise and lower

the drill string. These structure with-stands two types of loading: compressive

loading and wind loading.

Triple: It has the capacity of pulling 90’ stands of pipe

Double: It has the capacity of pulling 60’ stands of pipe

54

Single: It has the capacity of pulling 30’stands of pipe (one 30-ft

joint)

Stand:

A stand generally consists of two to four joints of made-up drill pipe. The stand

is generally used when running or pulling the drill string in and out of the hole.

Monkey board:

(Stabbing board) The platform on which the derrick man works when tripping

pipe.

Traveling Block:

The block and tackle which is rigged with the crown block by multiples of drilling

line strung between the crown block and the traveling block.

Draw works: Draw works drums are dynamically balanced to ensure smooth running.

The principal function is to convert the power source into a hoisting operation

and provide braking capacity to stop and sustain the weights imposed when

lowering or raising the drill string.

Shale Shaker:

The shale shaker is a contaminant removing device. It is used to remove the

coarser drill cuttings from the mud. This is generally the first solids-removing

device and is located at the end of the flow line. The shale shaker is composed of

one or more vibrating screens though which mud returns pass.

Swivel:

That part of the drill sting which connects the rotary hose to the drill string and

allows circulation and rotation at the same time.

Kelly:

The square or hexagonal member at the upper most part of the drill string

(immediately below the swivel) that passes through a properly fitting bushing

known as the kelly bushing or drive bushing. The drive bushing transmits rotary

motion to the kelly which results in the turning of the drill string.

Hook:

The hook is located beneath the traveling block. This device is used to pick up

and secure the swivel and Kelly.

55

56

Slips:

Latch around the drill pipe and seat in the rotary bushing in the rotary table. The

slips support and transmit the weight of the drill string to the rotary table while

making a connection or tripping pipe.

Tongs:

Large wrench-like devices that are used to tighten up and break out tool joints or

connections. The tongs are connected to the break out and make up catheads.

Deadline Reel and Clamp:

The drilling line strung through the traveling block and to the draw works is

secured by the deadline, which is wrapped around the deadline reel and clamped.

This prevents the line from slipping and the traveling block from falling.

Mud Pumps:

Mud pumps are used for circulating the drilling fluid down the drill pipe and out

of the annulus. These are high-pressure and high-volume pumps. They can be

double-acting duplex pumps or single-acting triplex pumps.

a). The double-acting duplex pump has four pumping actions per

pump cycle.

b). The single-acting triplex pump has three pumping actions per

pump cycle.

Desander – Desilter:

The desander and desilters are for contaminant or solids removal purposes. These

devices separate sand-size particles from the drilling mud. Both devices operate

like a hydro cyclone. The mud is pumped in at the top of the cyclone. This causes

the mud stream to hit the vortex finder which forces the mud down the cyclone

in a whirling fashion towards the apex of the cyclone.

- If used as a desander or desilter, the waste product is deposited at the

bottom and the fluid moving through the vortex finder is returned to the active

system. If used as a clay ejector, the under-flow contains barite particles which

are returned to the mud system, while the fluid moving out of the vortex is

deposited as waste.

- The difference between the various operations of the desander, desilter,

and clay ejector relate to the size of the cyclone.

Cyclone Size

Desander 6” or larger

57

Desilter 4” or larger

Clay Ejector 2” or larger

Degasser:

This vessel is used for gas contamination removal. It consists of a vessel which

has inclined flat surfaces in thin layers and a vacuum pump. The mud is allowed

to flow over the inclined thin layers which helps break out entrained gas in the

mud. The vacuum pump reduces the pressure in the vessel to about 5 psia which

extracts the gas from the mud. This device is about 99% efficient.

Mud Gas Separator:

This is generally the first device available to extract gas from the mud. It consists

of a tower with baffle plates, which are flat plates that force the fluid through a

certain path. The mud is allowed to flow in the tower over the baffle plates which

separates some of the entrained gas. This device generally can extract 50% to

60% of the gas.

Decanting Centrifuge:

A solids-control device which consists of a rotating cone- shaped drum which has

a screw conveyer attached to its outer surface. Rotation of the cone creates a

centrifugal force that throws the heavier particles to its outer housing.The screw

conveyer moves the separated particles to the discharge.

This device has to be monitored closely in a water-based mud because it allows

discharge of bentonite (gel). The bentonite controls viscosity and fluid loss. If

allowed to operate for long periods of time without adding bentonite to the mud

system, filtration control will be lost.

Accumulator:

The accumulator is a hydraulic system that maintains and stores enough high-

pressured fluid to operate every function of the blow-out preventors (BOP’s) at

least once and still have a reasonable reserve, as defined by the governing agency

rules. The system has a pump which pumps the hydraulic fluid into storage

bottles.

The storage bottles have floats which separate the hydraulic fluid from the gas

(nitrogen) in the upper part of the chamber. As fluid is pumped into the chamber

bottles, the gas is compressed, resulting in the pressure needed to move the

hydraulic fluid to operate the BOP’s.

58

Choke Manifold:

This is a system of valves and lines which are attached to the choke line, and in

some cases, kill line. The manifold is used to help control a well that has kicked

by diverting the flow to various functions such as an adjustable choke. It is

designed for versatility in diverting the mud flow after experiencing a kick.

Adjustable Choke:

The adjustable choke is usually hydraulically controlled from a remote panel

located on the rig floor. The purpose of the adjustable choke is to hold the correct

back pressure on a well when controlling a kick so as not to allow any more

formation fluid into the hole and/or prevent breaking the formation down while

controlling the well.

Drill Collars:

The drill collars are thick-walled heavy steel tubulars used to apply weight to the

bit. The drill collars should take all of the compressive loading, leaving the drill

pipe in tension.

Drill Pipe:

The major part of the drill string is composed of drill pipe. Drill pipe is specified

by its outside diameter, weight per foot, steel grade, and range (length). The drill

pipe transmits rotation, vertical movement and drilling fluid to the bit.

Heavyweight Drill Pipe:

Thick-walled heavy drill pipe is used in lieu of drill collars. It is generally used

in high-angled well where too many drill collars hamper drilling operations.

Standpipe:

The standpipe is that pipe which carries mud from the rig floor into the derrick to

the kelly hose. It must be pressure-tested to the working pressure of the BOP’s.

Kelly Hose:

The kelly hose is a section of high-pressured hose connecting the standpipe and

the swivel. The kelly hose allows for the vertical movement of the drill string as

well as circulation of fluid down the drill string.

Substructure:

The substructure provides the support for the derrick and derrick loading. It also

provides the necessary clearance beneath the rig floor for the preventor stack.

59

Cat Walk:

The cat walk is where the pipe is laid down from the drill floor. Any elevated

walkway may be referred to as a catwalk.

Introduction to Well Site Geology

WSG (Well Site Geologist) is an important member of the well site team,

commonly in charge of all geological services.

Its prime responsibility is to monitor vital operations during the course of the

well.

He Perform formation evaluation activities to ensure the well is drilled and

evaluated in most safe, efficient manner and cost effective.

Correlate the well data with off-set wells.

Collection, process and dispatch of geological samples.

Interpretation of formation evaluation data.

Send reports to station timely.

Mark formation tops.

Determine casing points, primary & secondary objectives and overpressure

intervals.

Selections of logging run intervals.

Important:

Petroleum Geologists are involved in all phases of oil exploration, from choosing

prospective sites through taking down the drilling rig after extracting the oil. This

can mean travel, long stays in unusual (and sometimes inhospitable) locations and

often with uncertain working conditions.

In order to maximize hydrocarbon recovery, petroleum engineers must be

involved in all stages of petroleum development and production. Such a broad

range of responsibilities guarantees a multi-disciplinary working environment

that requires expertise in a wide range of areas including petrophysics, drilling

and product operations, reservoir engineering, production geology, production

technology, and field development economics.

60

Tectonics The rock units of Precambrian and possibly early Paleozoic age (Salkhala and

Hazara Formations) and early and middle Paleozoic age (Tanawal Formation) are

mainly clastic, although the Salkhala Formation contains considerable nonclastic

carbonate material. A long period of mainly carbonate deposition, extending from

the Carboniferous to the Eocene, is recorded in a nearly complete sequence of

rock units totaling about 5,500 feet in thickness. Clastic deposits become

dominant in the middle and late Tertiary, reflecting the beginning of the

Himalayan orogeny, which ultimately deformed all rocks in the region.

The main episode of igneous activity took place in Late Cretaceous and early

Tertiary time and resulted in the synorogenic intrusions of the Mansehra Granite.

These granite rocks are thought to represent the southern fringes of the extensive

granite intrusions in the axial zone of the Himalaya. Postorogenic intrusive rocks

include mafic dikes and quartz veins, the latter thought to be associated with a

phase of weak hydrothermal activity, which produced veins of soapstone and

barite. In general, the grade of regional metamorphism increases northward and

also follows around the syntaxial bend (Hazara Kashmir Syntexis).

Northward, in the Darband, Oghi, and Battal areas, higher grade metamorphic

rocks are universal, including garnet, kyanite, staurolite, and sillimanite bearing

schists, as well as tremolite bearing marble. The pelitic and quartzose schists of

the high grade metamorphic terrane are considered to be equivalent to the

Tanawal Formation and the marble to the Kingriali Formation, although these

assignments are not certain.

Evidently only one period of metamorphism that connected with the Himalayan

orogeny has occurred in this area. The essentially unaltered shale, siltstone, and

limestone of the Hazara Formation in the southern part of the area tend to preclude

a period of meta- morphism in the Precambrian and Paleozoic. In addition, the

structural continuity between metamorphosed and unmetamorphosed rocks, as

well as the involvement of the Mansehra Granite in the deformation, points to the

close relationship between the Tertiary Himalayan orogeny and the

metamorphism. Contact-metamorphic effects in the rocks adjacent to the

Mansehra Granite are not particularly striking. In some places a narrow zone of

cordierite and andalusite schist has formed, but in other places virtually no contact

effects were noted. In the Balakot area, carbonate rocks adjacent to granite have

been some- what altered to calcsilicate rocks. Near Chitta Batta, 4 miles northeast

of Mansehra, Shams {1963) noted garnet, epidote, and wollastonite in calcareous

nodules within the Tanawal Formation, which shows that, in some places at least,

contact metamorphic effects are fairly strong. The interrelationships between

regional metamorphism, contact metamorphism, and the distribution of granite

need further work and would make an interesting study.

61

Fig 7.1 A view of Oghi-Khaki road

Regional Geology Mansehra Granitic Complex covers an area of about 150 km2. The apparent shape

of the complex is sheet like in geometry. According to the classification of

Sharma (1983) Mansehra Complex falls in the category of lesser himalayan

granitoids. The complex can be divided into the following major groups of rocks.

i. Older gneisses and granite comprised of deformed biotite rich granite

gneisses of possible Precambrian age such as Susalgali gneiss, Mansehra

granite, Andalusite and associated minor bodies.

ii. Younger tourmaline granite bearing of Cambrian age such as Hakla granite,

Sukal granite and associated acid minor bodies (pegrnatites, aplites, albitites).

iii. The metamorphic rocks form a continuous outer belt to the granitic

complex and alternate with granitic sheet in the interior of the area. The major

lithology comprises of Tanol formation that also borders the immediate

margins of the complex. For instance, in the SE, SW and West, the Tanol

formation is in tectonic contact with Salkhala metasedirnents of Precambrian

age (Wadia, 1930) consisting of phyllites, marble and quartz feldspathetic

units.

62

Geology of the Area The area is comprised of granitic and meta-sedimentary rocks intruded by the

dolerite dykes at several places. The granite is characterized by the flow direction

of phenocrysts in the in the rock. As you move along the road from top to down,

there is a dramatic change in the flow direction of phenocrysts which indicates

the flow of magma in different directions.

As the geomorphology of the oghi khaki section is hill top so this area is totally

comprised along the strike because of which granite, dolerites are repeated

respectively. Shear zone in the area indicates the gneiss which was manseha

granite in the past but it was transformed to the shear granite as the forces from

north sheared it.

Fig. 8.1 Shearing in Mansehra Granite

As we move further downslope Tanawal formation is present which a meta-

sedimentary rock is. Mansehra Granite intrudes Tanawal formation in the area

which shows that Tanawal formation is older than the Mansehra granite.

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Tanawal Formation Wynne (1879) described the rock units as “Tanol Group”. Middlemiss (1896)

called them “Tanol Quartzite”. Marks & Ali (1962) and Latif (1970) named them

“Tanol Formation”. Calkins, Offield and Ali (1969) used the name “Tanawal

Formation”.

Fig. 8.2 Outcrop of Tanawal Formation

Lithological Facies:

The various lithological facies of sediments that were involved in the regional

metamorphism are described below:

The psephitic facies:

It is a carbonate material that reacted with the silicate matrix with the production

of calc-silicate minerals.

The psammatic facies:

The psammatic strata grades gradually or abruptly into pure quartzitic material.

The change occur due to decrease in the mica content and increase in the grain

size of the psammatic material. The quartzitic rock sometimes contain feldspar

minerals and may approach arkosic composition.

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Fig. 8.3 Quartzite of Tanawal Formation

Pelitic psammatic banded facies

These rocks are characterized by an alteration of pelitic and psammatic bands.

Marble Facies These rocks are called marble associated, these are moderately foliated.

The mineral assemblage of the metamorphic rocks of the area show that regional

metamorphism was of Barrovian type. The metamorphic grades of the rocks we

observed are as follows:

Biotite grade rocks

Muscovite grade rocks

Garnet grade rocks

65

Granites and Gneiss This group includes Susalgali granite gneiss, Mansehra granite and the andalusite

granite. There all gradations between massive semi and true gneissic type, while

the intensity and frequency of foliation generally increase northwards.

Susalgali Granite Gneiss:

These rocks are greyish white to grey in color and are foliated. Rocks are

relatively coarse grained gneissose to granitoid rocks. Rocks are poor in quartz

and rich in feldspar. The fissures and joints developed in the rock mass are filled

in with pegmatites here. Mineralogical they are composed of potash feldspar,

plagioclase feldspar, muscovite, biotite and accessory minerals.

Mansehra Granite:

It is a sheet like body with an accurate appearance. This granite is in contact with

metasedimentary ricks with a gradation in the north and northwest while a small

part abut against the Hackle Granite. The Mansehra granite is at the contact is

sheared and even mylonized. The foliation of the granite and the metamorphism

at the contact is generally same. It contains xenoliths of variable size.

In the field It appears as whitish grey to grey, micaceous (muscovite) hard and

porphyritic. It consists of white to light grey quartz, dark biotite flakes,

subordinate muscovite etc. Quarts, tourmaline, monazite, zircon are the accessory

minerals.

Fig. 8.4

Xenolith

observed in

Mansehra

Granite

66

Fig. 8.5 Flow foliation in Granite

Types of Granites

There are different types of granites which includes S-type granite (supra-crustal),

it have heterogeneity due to the heterogeneous protolith.

M-type have overall uniform composition

I-type granite.

The younger granites In the periods of plutonic evolution of the Mansehra area there was a generation

of a number of bodies of tourmaline granites and microgranites equally rick in

albite (An6 to An10) and microcline with about 18% muscovite. Among the

tourmaline granites the Hackle granite is the largest.

67

Hackle Tourmaline Granite It is younger then Mansehra Granite. It is medium to coarse grained non-

porphyritic or weakly porphyritic granite with black tourmaline as one of the

essential mineral, plagioclase and microcline occur as white material greyish

translucent quartz with some biotite muscovite are other important minerals.

Contact between Hackle Granite and Mansehra Granite is chilled. Joints are well

developed at places are filled in by albite-aplite/pegmatites.

Fig. 8.6 Tourmaline observed in Hackle Granite

Andalusite Granite These are minor but important member of the older group of the granitic rocks

and occur as small lens like or pod like masses within the susalgali granite from

the enclosing gneiss by its finer grains and granitoid gneiss.

In the field this rock is distinguished/texture somewhat dark color by the presence

of small pink specks of Andalusite. Andalusite can be best seen in the field if

some water is thrown on the rock then the andalusite mineral starts gloving.

68

Dolerite Dyke

Dykes are the solidified magma which have intruded in the host rock at an angle.

Composition of Dolerite dykes:

Plagioclase, Hornblende and K-feldspar are the main minerals of dolerite dyke

which is equivalent to gabbro. It is coarse grained and contains tourmaline

crystals. Quartz is also present which is transparent. It is plutonic rock.

Dolerite dikes have intruded into the igneous granitic rock which indicates that

dike is younger then the granite.

Himalayan orgeny has not affected the dolerite dykes.

Fig. 8.7 Intrusion of Dolerite dyke in Mansehra Granite

Observations

Day 8 (30-08-2013) In Igneous-Metamorphic Mapping, we observed:

Tanol Formation

Mansehra Granite

Dolerite dyke

69

We also observed stress released joints, quartz vein, and heterogeneous

composition.

Fig. 8.8 Contact between Mansehra Granite and Dolerite dyke

Day 9 (31-08-2013) We observed:

Shearing Zone

Dolerite dyke

Leucocratic granite

Contact between Mansehra granite and Tanol Formation

Garnet Mica Schist

Andalusite Grade

We also observed Carlsbad twinning and conjugate joints.

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Fig. 8.9 Carlsbad twining in Mansehra Granite

71

Fig. 8.10 Contact between Melanocratic Granite and Leuccocratic Granite

Day 10 (01-09-2013) The following sequence and contacts were observed:

Contact between Mansehra Granite and Tanol Formation

Contact between leucocratic and melanocratic granite.

Contact between Mansehra and Hackly Granite.

We also observed tourmaline in granite.

72

Fig. 8.11 Contact of Mansehra Granite and Dolerite dyke

73

Introduction to Dam A dam is a check across the flow of a river/channel. There are many

classifications of dams:

Based on Usage

Base on Purpose

Based on Construction Material

Based on Cross-Section

Classification on the basis of Usage:

i). Storage Dam:

A dam which is used to store the water into reservoir

ii). Diversion Dam:

A dam which is used to divert the course of water

iii). Detension Dam/Delay action Dam:

In arid regions where water may join the groundwater through infiltration, dam

is built to increase groundwater storage.

Classification on the basis of Purpose:

i). Uni-purpose Dam:

A dam build up for only one purpose e.g, Rawal dam, Khanpur dam.

ii). Multi-purpose Dam:

A dam which is build up for two or more than two needs e.g, Tarbela dam, Mangla

dam.

Classification on the basis of Construction material: i). Concrete Dam

a). Concrete gravity:

74

Gravity dam uses its rectangular shape and the shear weight of their rock and

concrete structure to hold back the water in the reservoir.

b). Concrete arch:

Arch dam utilize the strength of an arch to displace the load of water behind it

onto the rock walls that it is built into.

c). Concrete buttress:

Buttress dam that uses multiple reinforced columns to support a dam that has a

relatively thin structure. Because of this, these dams often use half as much

concrete as gravity dams.

ii). Rockfill Dam

Rockfill dams are embankments of compacted free-draining granular earth with

an impervious zone. The earth utilized often contains a large percentage of large

particles hence the term rock-fill.

iii). Earth & Rockfill Dam:

Earth & Rockfill Dams have a relatively narrow, impermeable earth or clay core

inside the dam but most of the dam is constructed of permeable rock fill which, by

itself, would be incapable of retaining water. The impermeable membrane in these

dams is the clay core.

Classification on the basis of Cross-section:

i). Zoned Dam

ii). Homogeneous Dam

Basic Terms Related to Dam Reservoir:

A natural or artificial pond or lake used for the storage and regulation of water.

Upstream:

Side from which water is coming.

Downstream:

Side to which water is flowing.

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Right and Left banks:

When facing downstream the bank on our right side is right bank and on left is

left bank.

Abutment:

That part of the valley side against which the dam is constructed.

An artificial abutment is sometimes constructed where there is no suitable natural

abutment.

Right and left abutments are those on respective sides of an observer when

viewed.

Looking downstream the wall between a spillway or gate structure and the

embankment

Service spillway:

A spillway that is designed to provide continuous or frequent regulated or

unregulated releases from a reservoir without significant damage to either the

dam or its appurtenant structure

Outlet:

An opening in which water can be freely discharged for a particular purpose

From a reservoir

Crest of Dam:

Maximum crest of body of dam

Maximum water level

The level to which we can store water just some feet under crest level

Dead Storage Level:

The level of water under the outlets

Free board:

Difference between the crest level and maximum water level

Toe:

The junction of the downstream face of a dam with the ground surface.

76

Also referred to as the downstream toe. For an embankment dam, the junction of

the upstream face with the ground surface is called the upstream toe.

Heal:

The junction of the upstream face of a dam with ground surface

Catchment Area:

The area drained by a river or body of water.

Observations

Day 11 (02-09-2013) We visited Tarbela Dam. A lecture on micro seism-monitoring system was hold

by team of WAPDA. They briefed us about antelope software and its objectives.

After this we went along side of Dam and observed its components and working

including spillways, power station, reservoir area, abutment, tunnels.

Fig. 9.1 Satellite image of Tarbela Dam

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Tarbela Dam Tarbela Dam is located on the Indus River in Pakistan is the largest earth filled

dam in the world and second largest by structural volume. It is located in Haripur

District, Hazara Division, Khyber Pakhtunkhwa, about 50 kilometres (31 mi)

northwest of Islamabad.

Location:

Place name: Tarbela

Latitude: 34° 00' 02" N

Longitude: 72° 38' 15" E

History of the Tarbela dam: The Tarbela Dam is one of the largest earth and rockfill dam of the world. The

primary function of the Tarbela project was to regulate the Indus River flows for

the benefit of irrigation. A secondary function is the generation of electric power.

Incidental benefits include limited flood control of the Indus River, a substantial

contribution to tourism, commercial fishing possibilities and added employment

opportunities during and after construction.

The reservoir was completed in 1977 with units 1 - 4 providing 700 MW of

power. Units 5 - 8 of 700 MW were added in 1982. Units 9-10 of 350 MW were

completed in 1985 and finally units 11 - 14 of 1,728 MW were completed in

1992-93, making the total power generation capacity of Tarbela Dam 3,478 MW.

Dam Type: Earth and Rockfill

Height: 485 ft. (above riverbed)

Reservoir Area: 95 sq. miles

Gross Storage Capacity: 11.62 MAF

Live Storage Capacity: 9.7 MAF

Main Spillway Capacity: 6.5 million cusecs

Year of Completion: 1977

Geology & Bedrock: Alluvium under Main Dam and

Limestone, Phyllite and Schist under the

Abutment

Power Generation: 3,478 MW

78

Catchment area of the Tarbela Dam Catchment area of the reservoir created by the dam is 169,600 square kilometers.

The reservoir, with a maximum depth of more than 450ft, can impound up to

11.62 million acre foot (MAF) of water at the maximum lake elevation of 1,550ft.

Net usable capacity of the reservoir is 9.68MAF.

The water is stocked during the months of June, July and August, when the river

flow is at its maximum.

Major parts of the Tarbela Dam Reservoir:

The Tarbela reservoir stores water during the summer months of June, July and

August when water either causes disaster by flooding in the surrounding areas or

goes waste into the sea.

50-miles long reservoir

Gross storage capacity of 11.6 million acre feet

Net usable capacity of 9.7 MAF

It is to be noted that more dams can be constructed on Indus since its annual

flow is substantially more than is being stored at present.

Fig. 9.2 Reservoir of Tarbela Dam

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Main dam:

Main dam overlies 700ft alluvium.

An embankment is 9,000 feet long.

Maximum height of dam is 465 feet.

The main embankment is a carefully designed, zoned structure composed of

impervious core, bounded on both sides by gradually increasing sized material

including coarser sands gravels cobbles and finally large sized riprap on the outer

slopes.

A 24 feet thick filter drain mattress under the embankment together with nearly

vertical chimney drain provides the necessary facility to collect the seepage

Service Spillways:

On the left bank two spillways discharges into a side channel.

The total spillway capacity is 1,500,000 cusecs which constitutes the peak

outflow resulting from routing the probable maximum flood.

The service spillway having 44 percent of the total capacity is sufficient to pass

all but very rare floods.

Its maximum discharge capacity is 650,000 cusecs.

Fig. 9.2 Service Spillway of Tarbela Dam

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Auxiliary Spillways:

The auxiliary spillway is similar in design to the service spillway.

It has nine radial gates with crest elevation of 1492 feet (455 meters).

Flip bucket is at an elevation of 1220 feet (372 meters).

A longitudinal drainage gallery along with a network of drainage pipes under the

channel and the head works has been provided to release pore water pressure in

both the spillway foundations.

Fig. 9.2 Auxiliary Spillway of Tarbela Dam

Auxiliary Dam:

The auxiliary dams resembling the main embankment dam in design close the

gaps in the left periphery of reservoir.

The smaller of the two auxiliary dams, however, has a vertical core extending

down to the underlying rock

The larger auxiliary dam has a short upstream blanket terminating in a cut off to

rock.

Auxiliary Dam 1

Auxiliary Dam 2

81

Check dam:

A small dam constructed in a gully or other small water course to decrease the

streamflow velocity, minimize channel erosion, and promote deposition of

sediment and to divert water from a channel.

Discharge:

Volume of water released from a dam or powerhouse at a given time, usually

expressed in cubic feet per second.

Embankment Dam:

A dam structure constructed of fill material, usually earth or rock, placed with

sloping sides and usually with a length greater than its height.

Spillway:

The channel or passageway around or over a dam through which excess water is

released or "spilled" past the dam without going through the turbines. A spillway

is a safety valve for a dam and, as such, must be capable of discharging major

floods without damaging the dam, while maintaining the reservoir level below

some predetermined maximum level.

Turbine:

A mechanism in a dam that rotates with the force of water and produces

electricity.

Storage:

The volume of water in a reservoir at a given time.

Sluiceway:

An open channel inside a dam designed to collect and divert ice and trash in the

river (e.g., logs) before they get into the turbine units and cause damage.

Powerhouse:

A primary part of a hydroelectric dam where the turbines and generators are

housed and where power is produced by falling water rotating turbine blades.

Peak flow:

Refers to a specific period of time when the discharge of a stream or river is at its

highest point.

Inflow:

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Water that flows into a reservoir or forebay during a specified period.

Diversion Dam:

A barrier built to divert part or all of the water from a stream into a different

course.

Power tunnels:

The four, each of half mile long, tunnels through the right (rock) abutment

initially served for the diversion of water during the final phases of construction

of the Project.

Now they are being used for Power generation (tunnels 1, 2, 3 and eventually 4).

The discharge capacity of each irrigation tunnel at higher reservoir elevations is

approximately 90,000 cusecs.

The discharge pass through energy dissipator structures and the water returns to

the river.

A fifth tunnel on the left bank designed to augment irrigation releases upto 80,000

cusecs (2,265 cumecs) at high reservoir level, has also been added to the project.

Power House:

Four (4) power units of 175 MW generating capacity each were to be installed on

each of the tunnels 1, 2 and 3 located on the right bank with the ultimate installed

capacity of 21,00 MW.

Due to increasing prices of the fossil fuel, the Govt of Pakistan has been laying

greater emphasis on generation of cheap Hydal power.

In pursuance of this policy, WAPDA carried out studies to tap the maximum

power potential of Tarbela. As a result, it has been found possible to install six

(6) units, instead of four (4) only on tunnel NO.2.

Units 5 to 8 on tunnel NO.2 were commissioned in 1982, and units 9 and 10 in

1985.

Based on studies, four power units of 432 MW capacities each were installed on

tunnel NO.3.

Thus the total ultimate power potential of the project enhanced from 2100 MW

as originally planned to 3478 MW

83

Geology of the Dam Foundation of the Dam:

Lower most Formation is Hazara Formation faulted contact with Abbottabad

Formation and contact with Tanol Formation. Some igneous intrusions underlain

by alluvium.

Left abutment of Auxiliary Dam 1 is Tanol Formation (quartzite) and limestone

of Abbottabad Formation.

Right bank consists of schist and quartzite.

Both Auxiliary and main Spillways on Abbottabad Formation

Faults in the area of dam:

Faults running through the dam area are given below:

Darband Fault

MBT

Punjal Fault

Hazara Fault

Faults and the resulting Earthquake with magnitude given below

Faults Magnitude of Earthquake

Darband 6.5

Punjal 7.5

Detatchment 8

Antelope Software Sensors for weak and strong motion

Seismometer

Accelerometer

Seismometer Accelerometer

Very sensitive Low sensitive

84

Seismic monitoring Engineering purposes

Antelope Real Time System (ARTS)

Used for:

Real time acquisition

Real time data processing

Command and control

Excellent database

Objectives of Antelope Software:

Different colors represent different magnitudes of earthquake;

Blue iv-v

Yellow v-vi

Red vii

Geomorphology of the Dam:

Main source of water is the river Indus and 2nd Dor River. Other rivers such as

Siran River, Harrow River and Kunhar River also joints the Tarbela Dam. The

Indus rises about 280 miles away from Ladakh, while the Siran, Dor and Harrow

take start from Bhogharamang Valley, Dunga Galli (near Nathia Galli) and Lalu

Sar Lake (Naran Valley) respectively.

Objectives of Tarbela dam:

1) Design to store water from Indus River for irrigation.

2) Storage of water for flood control.

3) Generation of hydroelectric power.

85

Economic Geology Minerals are the important part of the any country’s economy. They are very

important for any country’s development. Economic geology deals with the

minerals which are economically important. Economic geology of any area tells

about the industrial valuable minerals present there. In Hazara Area there are also

valuable minerals and rocks which have been discussed in this chapter and are

given below:

Limestone

Laterite

Coal

Pyrite Nodules

Fire clay

Gemstones

1) Garnet

2) Tourmaline

Dam

Petroleum Rig

Limestone Quarry in Saman suk Formation, Lockhart Limestone and Kawagarh Limestone.

Observations:

The major use of limestone is as a crushed rock for use in construction, mainly as

an aggregate and filler in concrete and road stone.

Limestone competes with other hard rock aggregates.

Some limestone sand is also used in concrete and mortar.

Limestone mining (Economic Importance)

1. Cement industry

2. Aggregate

3. Building stone

Laterite

A red residual soil formed by the leaching of silica and by enrichment with

aluminum and iron oxides, especially in humid climates.

Observations:

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Red to maroonish yellow Laterite band in Hangu Formation

Economic importance:

Laterites are economically most important for ore deposits, such as bauxite.

Iron ore Laterite is the essential component of cement formulation.

Strong, hardened varieties of laterite are sometimes cut into blocks and used

as brick stones for building houses.

Hardened laterite varieties are also applied for the construction of simple roads

Nowadays, solid lateritic gravel is readily put in aquaria where it favors the

growth of tropical plants.

Ores are concentrated in metalliferous laterites; aluminum is found in bauxites,

iron and manganese are found in iron-rich hard crusts, nickel and copper are

found in disintegrated rocks, and gold is found in mottled clays.

Coal Coal is a bio-sedimentary deposit formed by the slow action of heat and pressure

on forests buried in the long past.

Fig. 10.1 Coal mining in Hangu Formation

87

Observations:

Mining in the Hangu and Chichali formations

Economic Importance of Coal:

Of all known sources of energy, coal is the most important source supplying more

than 55% of heat and energy in the world.

It is the source of valuable products gases, tar, oils, pitch, coke, ammonia;

fertilizers, synthetic dyes and numerous drugs.

The cement industry is also a major coal user.

Pyrite Pyrite is a brass-yellow mineral with a bright metallic luster with a nickname of

"Fool's Gold" it is surprising that pyrite often contains significant amounts of gold

Observation:

Pyrite nodules in Hangu Formation

Economic Importance:

Pyrite used to be an important ore for the production of sulfur and sulfuric acid.

The most important use of pyrite is as an ore of gold. Gold and pyrite form under

similar conditions and occur together in the same rocks. Some pyrites can contain

0.25% gold by weight or more.

Pyrite is occasionally used as a gemstone. It is fashioned into beads and carved

into shapes.

Fireclay Mineral aggregate composed of hydrous silicates of aluminum

(Al2O3.2SiO2.2H2O) with or without free silica.

Observation:

Fireclay is grey, whitish grey on fresh surface and weathered in variegated colors

as yellow and red was observed in Hangu Formation.

Economic Importance:

Fire clay is used in the manufacture of ceramics, especially fire brick.

Fire clay is used to line blast furnaces, glass furnaces, fireboxes, kilns, and

crucibles. It is rich in silica and alumina.

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Gemstones Garnet:

Garnet is used as gemstone and has high market value. There are abundant

crystals of garnet in garnet grade of metasedimentary rocks of Oghi-Khaki road

but crystals are not very big in size.

Tourmaline:

Tourmaline in pegmatite veins can be cut to be used as gemstone.

Tarbela Dam 4) It used to be the first largest dam in the world.

5) Design to store water from Indus River for irrigation.

6) Storage of water for flood control.

7) Generation of hydroelectric power.

8) Owner of the Dam is WAPDA.

Mining in Hazara Though mining in Hazara has not been done on a large scale but minerals of

different kinds like Coal, Lime Stone, Building stone, Gypsum, Coarse Slate,

Antimony or oxide of led (Surma, Kajal) and iron are founded in abundance in

this area. Some of the minerals mined within the district Abbottabad are barite,

dolomite, granite, gypsum, limestone, magnetite, marble, and phosphate, red

ochre and red oxide.

Oil well Petroleum industries can be serve as a backbone of economy to any country. In

Pakistan at the present time only Oil industries are working as profitable

industries. In contrast to the oil industries in the world the rate of hitting oil well

in Pakistan is 1/2.5 while in all over the world this ratio is very much greater

which is 1:9.