Structural Modeling of Upper Part of Indus Basin using the 'Exploration Seismology, Earthquake Seismology, Well logs and remote Sensing.

Abstract

This M.Phi! work is an attempt toward the integration of different field of Geophysics which includes the Exploration Seismology, Earthquake Seismology, Well log and Satellite imageries to study the structural model of the area. Area of research lies at about 100Km from Islamabad in the southern Potwar Platform Slop of upper Indus Basin. Most of the Exploration Seismology data obtained from Directorate General Petroleum Concession (DGPC) which includes 18 Seismic lines of two seismic surveys i.e. 881-CW & 884-CW, Composite Well logs and Seismic lines· Base map. Earthquake Seismology data was obtained from United States Geological Survey (USGS), International Seismological Centre (ISC) and IIEES. Satellite imageries were obtained from Google Earth and Blue Earth. These satellite imageries were geo-referenced before use as an seismic lines overlay. Interpretation of seismic data involves the marking of seismic horizons, generation of time contour maps, depth contour maps and depth surface maps, velocity variation in the sedimentary layers are studied in the fo rm of velocity model generation and fence diagram generation with the overlay of time contour map of both the surveys. Seismicity in the area of research was studied using the statistical approach by using the time analysis, depth analYSiS, magnitude analysis of the earthquake data. 'b' value in the area of research was calculated by using the window based software named as ZMAP with using the definition file of Matlab.7. Area of research lies in the compression regime and contains numbers of thrust faults in which most of them trends North-East South-West word. Deeper faults terminate in salt-range formation which provides the decollment surface between the lower meta-sedimentary basement and the upper sedimentary rock. Due to the damping effect of the salt range formation, seismicity in the area of research is low but the Fault Plane Solution (FPS) shows the same behavior as observed through the seismic data interpretation. By integration of all the information it is believed that in generation of structures in the area of research, basement is also involved together with the compression forces and salt decollment.