I= TECTONIC INTERRELATIONSHIP BETWEEN KHUNZDAR REGION AND SUBMARINE ARABIAN SEA STRUCTURES AND THEIR ECONOMIC POTENTIALS
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Title of Thesis
TECTONIC INTERRELATIONSHIP BETWEEN KHUNZDAR REGION AND SUBMARINE ARABIAN SEA STRUCTURES AND THEIR ECONOMIC POTENTIALS

Author(s)
Noushaba Hisamuddin
Institute/University/Department Details
University of Karachi/Department of Geology
Session
2004
Subject
Geology
Number of Pages
282
Keywords (Extracted from title, table of contents and abstract of thesis)
khunzdar region, submarine arabian sea structures, crustal features, southern indus basin, indo-pakistan continental plate, mineralization, seismicity, khuzdar knot

Abstract
The geological setting of Pakistan is unique and characterizes tectonic junctions of different interactive plates and micro plates within an area of about 800,000 sq km comprising of large fold-thrust belt transversed by numerous complex and significant geological anomalous trends and structures. Khuzdar Knot, the study area, is one of such anomalous features transversing the north-south oriented axial-fold-thrust belt of Pakistan. Likewise the offshore region of Pakistan has enigmatic crustal features

A number of hypotheses and models were proposed by the geoscientists from time to time to explain the formation of Khuzdar Knot, the structures exposed in its surrounding areas and the offshore submarine crustal features mainly based on the surface geological and geomorphological expressions

The present integrated geophysical studies comprising of seismicity, gravity and magnetic techniques supplemented by the available geological data have unearthed the surface and the subsurface tectonic interrelationship among the Khuzdar & its surrounding areas and the submarine features, i.e., Murray Ridge, Owen Fracture Zone etc. These studies have also delineated the deep-seated structures within the basement and their ongoing tectonic activities and relevant processes responsible for the tailoring of tectonic pictures of the Khuzdar & its surrounding areas and the bottom of the Arabian Sea. Ridge, Owen Fracture Zone etc. These studies have also delineated the deep-seated structures within the basement and their ongoing tectonic activities and relevant processes responsible for the tailoring of tectonic pictures of the Khuzdar & its surrounding areas and the bottom of the Arabian Sea. Moreover, the study has also revealed new prospects for the hydrocarbon and mineralized horizons, their tectonic associations and selection of priority areas for the future research and exploration activities

Integration of the geophysical and geological data have revealed the east-west actuate structural trend in Khuzdar and surrounding areas, which appears as the results of the transcurrent movement associated with the southern Indus basin fossil rift under the influence of the ongoing anticlockwise rotational movement of the Indo-Pakistan continental plate. This transcurrent zone changes its orientation towards south-west, which is manifested at the surface as the drag effects of the east-west oriented Makran flysch mountain ranges towards north-east. The gravity and the seismic analyses show that the transcurrent zone has left lateral deformational trend, which is creeping in space and time towards Makran coast and segmenting the Arabian oceanic plate

Gravity modeling shows an imbricate oblique transcurrent fault system passing across the Khuzdar area and causes crustal shortening within the narrow zone, which appears to develop regional duplex structures favorable for the hydrocarbon accumulation. A number of Pb-Zn-barite mineralization associated with the deformed structures indicates the complete structural control for the mineral occurrences

Tensor analyses of earthquake events occurred in Panjgur-Kharan basin reveal the presence of a rift basin, which has been first time identified by the gravity data analyses. The presence of this structure indicates the northward migration of Chagai volcanic are and change in the angle of western segment of the Arabian oceanic plate. The rift basin seems to be the potential structure for the hydrocarbon accumulation and as well as for the deposition of antimony, mercury gold etc. minerals in traces most probably similar to Andaman rift basin

Seismic data have one of the right lateral transform fault of Carlsberg spreading ridge center, which is abnormally extending northward in the alignment of Khuzdar-NAI-Jabri transcurrent zone. It is expected that these two transcurrent-transform land and the sea features will join together in near future geological time

On the eastern side of the Owen Fracture Zone, the Murray Ridge complex has been revealed as a rift basin, which most probably seems to continue in the north-east direction and joins with the Indus fossil rift structural basin. The magnetic data show that the little Murray Ridge structure corresponds with the Khuzdar-Bela ophiolite zone exposed on the land. Its is also inferred that due to the re-activation of Indus basin rift structure, the intensity of the deformation of ophiolite zone increases from sea to landward

The integrated models based on the results of the present study now clearly demonstrate the distribution and direction of domains of the tectonic forces in and around the study area. Moreover, these models have also established the interrelationship among the surface and the deep-seated deformed structures vertically and as well as laterally, which provides guidelines for the exploration of oil & gas and the various mineral potentials

Download Full Thesis
3420.51 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
188.18 KB
2 1 Introduction 1
192.47 KB
  1.1 General statement 1
  1.2 Previous work 9
  1.3 Geophysical methods applied for the study 15
3 2 General geology of the area 20
449.66 KB
  2.1 Khuzdar area 20
  2.2 Geology of the coastal area 47
  2.3 Off shore area 51
4 3 Seismicity in Khuzdar and Arabian sea 55
568.28 KB
  3.1 Collection of seismicity data 59
  3.2 Seismicity distribution in Khuzdar and adjoining areas 61
  3.3 Seismicity trend on land and sea 69
  3.4 Seismicity correspondence on land and sea 73
  3.5 Earthquake frequency with respect to time & space 76
  3.6 Earthquake frequency with respect to time & depth 81
  3.7 Focal mechanism of the study area 85
  3.8 Correlation of tensors with exposed geological structures in Khuzdar and adjoining areas 91
  3.9 Correlation of tensors with submarine features of the Arabian sea 93
  3.10 Correlation of tensors with the basement features 95
  3.11 Seismo-tectonic models for the basement features in Arabian sea , Khuzdar & its surrounding areas 97
5 4 Gravity anomalies of Khuzdar and Arabian sea 101
416.7 KB
  4.1 Collection of ground gravity data 102
  4.2 Analysis of gravity data 102
  4.3 Correlation of gravity data with exposed geological structures 108
  4.4 Correlation of gravity data with exposed geology 111
  4.5 Gravity modeling for the Khuzdar area 113
  4.6 Satellite gravity data and their interpretation 117
6 5 Magnetic anomalies of Khuzdar area and Arabian sea 130
300.13 KB
  5.1 Magnetic anomalies in Khuzdar and surrounding areas 131
  5.2 Analyses of magnetic anomalies of the Arabian sea 144
  5.3 Correlation of magnetic anomalies with physiographic features of land and sea 146
  5.4 Correlation of magnetic anomalies with the satellite gravity data 148
7 6 Proposed tectonic models for the geological features of the study area 150
449.37 KB
  6.1 Review of general geological development of Pakistan 151
  6.2 Present observation and previously suggested models for the Khuzdar knot 155
  6.3 Propsed geophysical models of Khuzdar area 156
  6.4 Proposed basement model of Khuzdar and surrounding areas 160
  6.5 Submarine features of Arabian sea 172
  6.6 Schematic model for the geological features of land and sea 178
8 7 Tectonic events and prospects of economic minerals and hydrocarbons 182
480.3 KB
  7.1 Possible prospects of hydrocarbon and gas hydrates 183
  7.2 Mineral prospects in Khuzdar region 192
  7.3 Mineralization within ophiolite zone 212
9 8 Discussions 218
132.41 KB
10 9 Conclusions 229
65.29 KB
11 10 Recommendations 234
538.93 KB
  10.1 Bibliogralphy 237
  10.2 Appendix 261