Composite Magnetic Anomaly Map of India and its Contiguous Regions

Abstract Advancement in Instrumentation technology, accurate aircraft positioning using GPS coupled with sophisticated computers and data processing and imaging techniques have improved the resolution of airborne magnetic surveys manifold which can now provide super-high resolution aeromagnetic maps This has catapulted into several countries repeating their magnetic surveys with the improvement in technology especially in regions of viable resources Unfortunately, India still does not have a complete aeromagnetic survey of the whole country even at the reconnaissance level In this paper, we have put together all available ground and marine magnetic data collected by different agencies, to complement the available aeromagnetic data over India and its contiguous regions and produced a composite magnetic anomaly map at an altitude of 5000 feet It has been our endeavour to show the impoitance of a magnetic anomaly map in bringing out the structural details related to tectonic activity by looking below the sediments, Deccan traps, etc From the composite magnetic anomaly map it appears that there is a region that has been subjected to high tectonic activity, running across the Centre of the Indian subcontinent from the western offshore to the Brahmaputra valley in the east, dividing the country into a northern and southern block It is hoped that the National Agencies will take up the aeromagnetic coverage of India, on a priority basis and survey the entire region where aeromagnetic coverage has not been undertaken, including the Deccan trap covered regions A magnetic anomaly map produced by uniformly distributed data collected on a single platform will certainty provide more reliable information