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Title of Thesis

Structural Analysis Of The Trans-Indus Ranges: Implications For The Hydrocarbon Potential Of The Nw Himalayas, Pakistan

Author(s)

Amjad Ali

Institute/University/Department Details
National Centre Of Excellence In Geology / University Of Peshawar, Peshawar
Session
2010
Subject
Geology
Number of Pages
280
Keywords (Extracted from title, table of contents and abstract of thesis)
Structural, Analysis, Trans-Indus, Kalabagh, Surghar, Marwat, Ranges, Implications, Hydrocarbon, Potential, Himalayas, Pakistan

Abstract
The Trans Indus ranges constitute the western end of the frontal ranges that border the active foreland fold-and-thrust belt of the Himalaya in North Pakistan. Over 200 line km of 2D seismic data and sub-surface information of seven wells drilled in the surrounding areas have been integrated with surface geological information in order to understand the structural evolution of the Trans Indus ranges.
Cambrian to Eocene platform succession unconformably overlain by a thick pile of fluviatile molasse deposits outcrop along the Trans-Indus ranges. The Trans-Indus ranges display pronounced structural swings in plan view, giving rise to a pair of reentrants known under the name of Kalabagh and Tank. Both these re-entrants are flanked by wrench zones in the east and west that have produced contrasting styles within the Trans-Indus ranges. The structural styles include south-verging anticlinalmonoclinal ridge above a frontal fault, wrenching and compression related en-echelon anticlines and fault bend folds. The current investigations have led to the understanding that the structural evolution of the east-west and east-north-east oriented segments of the Trans Indus ranges is attributed to a south directed ramping whereas the northsouth/ northwest trending segments are related to wrenching concomitant with compression. The frontal bounding fault in the Trans-Indus ranges is less significant as compared to that along the Salt Range in terms of its level of decoupling and the magnitude of southward translation.
The Himalaya-related deformation that shaped the Trans-Indus ranges is distinguished into three discrete episodes including pre-molasse, syn-molasse and post-molasse. The pre-molasse deformation includes the extensional tectonic activity resulted in the development of the normal basement faults with down thrown side to the north. The synmolasse deformational episode is well demonstrated by the gradual south-younging sequence of molasse deposits in the Kohat Basin. The post-molasse deformational episode started in the region at the time when the macroscopic thrust slab underneath the Kohat-Bannu Basin ramped up section at the site of Trans Indus ranges. This ramping led to the creation of the present day Trans-Indus ranges and the internal deformation of the thrust slab which is still continuing.
The arcuate nature of the Trans Indus ranges is interpreted to be original, partly controlled by some pre-existing basement irregularities and possible strain partitioning. It is interpreted that the onset of compression at the northern and southern Surghar Range and Manzai ranges was synchronous caused by north-south and east-west compression induced by proto Main Boundary Thrust and Kurram Fault respectively. At the time when Proto MBT was transmitting south directed stresses at the site of the northern Surghar Range, left lateral wrenching along the Proto Kurram zone was transmitting east directed compressive stresses resulting in the north-south oriented folds in the Manzai and southern Surghar Range. The onset of thrusting is believed to be the earliest at the site of Surghar and Manzai ranges followed by wrenching along Pezu, Kundal and Makarwal faults. This wrenching episode was subsequently followed by thrusting at the site of Khisor and Marwat ranges.
The stratigraphic succession and structural styles observed within the Trans Indus ranges offer a complete petroleum system comprised of multiple reservoir, source, seal rocks and traps including structural as well as stratigraphic for the accumulation of hydrocarbons.

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17,389 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 CONTENTS

 

i
25 KB
2

1

INTRODUCTION

1.1 General Description
1.2 Location
1.3 Scope Of Study
1.4 Historical Review
1.5 Exploration Activities In The Region
1.6 Methodology
1.7 Geological Setting

1
534 KB
3 2 REGIONAL TECTONIC FRAMEWORK

2.1 Tectonic Setting
2.2 Tectonic Evolution
2.3 Structural Setup

15
933 KB
4 3 STRATIGRAPHY OF THE SURGHAR RANGE

3.1 Summary
3.2 Stratigraphic Setting
3.3 Stratigraphic Analysis

36
1,902 KB
5 4 STRATIGRAPHY OF THE MARWAT-KHISOR RANGE

4.1 Summary
4.2 Stratigraphic Setting
4.3 Stratigraphy Of The Sheikh Budin Hills
4.4 Stratigraphic Analysis

67
1,328 KB
6

5

STRATIGRAPHY OF THE MANZAI & SURROUNDING AREA

5.1 Summary
5.2 Stratigraphic Succession
5.3 Stratigraphic Analysis

94
584 KB
7

6

STRUCTURAL GEOMETRY OF THE SURGHAR RANGE & KARAK AREA

6.1 Introduction
6.2 Physiography
6.3 Structural Data
6.4 Structural Model

109
2,992 KB
8

7

STRUCTURAL GEOMETRY OF THE MARWAT-KHISOR RANGES

7.1 Introduction
7.2 Physiography
7.3 Surface Geology Of The Marwat-Khisor Ranges
7.4 Structural Model

146
2,182 KB
9

8

STRUCTURAL GEOMETRY OF THE PEZU-BHITTANI RANGE

8.1 Introduction
8.2 Physiography
8.3 Surface Geology Of The Pezu-Bhittani Ranges
8.4 Structural Model

166
1,840 KB
10

9

STRUCTURAL GEOMETRY OF THE MANZAI RANGE

9.1 Introduction
9.2 Physiography
9.3 Surface Geology Of The Manzai Range
9.4 Structural Model

184
1,374 KB
11

10

HYDROCARBON POTENTIAL OF THE TRANS INDUS RANGES

10.1 Summary
10.2 Source Rock Potential
10.3 Reservoir Potential
10.4 Seal/cap Rocks
10.5 Play Types
10.6 Hydrocarbon Potential Of The Manzai Area
10.7 Structural Style And Hydrocarbon Traps

201
1,071 KB
12

11

DISCUSSION AND CONCLUSIONS

11.1 Structural Styles Of The Trans Indus Ranges
11.2 Comparative Statement Of The Structural Styles In The Salt And Trans Indus Ranges
11.3 Sedimentation & Deformation Scheme Of The Trans Indus Ranges
11.4 Arcuate Nature Of The Trans Indus Ranges
11.5 Sequential Evolution Of The Trans Indus Ranges

229
2,794 KB
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12

REFERENCES

 

253
90 KB