Airborne Magnetic Data - A Source of Subsurface Geological Information for Uranium Exploration: A Few Case Studies over some Proterozoic Sedimentary Basins of India.

摘要

Airborne survey was first used in India by AMD in the year 1956 for exploration of uranium. At the initial stage it was aimed to locate near surface Uranium anomalies. Acquisition of magnetic data along with radiometric data started from the year 1972. So far, AMD has acquired valuable aeromagnetic data amounting to nearly 5.2 lakh sq km area, spread over important Uranium Provinces of India. Quality of the aeromagnetic data has improved through the ages with the application of new technologies. The most recently collected aeromagnetic data collected by heliborne survey over parts of Vindhyan basin accurately sampled subtle magnetic anomalies at the basement. Aeromagnetic survey is an effective tool for studying basement features of Middle Proterozoic sedimentary basins. Nonmagnetic (low susceptibility) sediments overlying the basements of distinctly higher susceptibility makes this possible. Study of Aeromagnetic maps over Bhima, parts of Chhattisgarh, Bijawar, Gwalior and Vindhyan basins has deciphered many important geological features viz. basement morphology, movements of basement blocks along faults and continuation of fracture/fault associated with higher value of uranium below the sediment. AMD will continue to cover more and more areas by airborne surveys in future days to meet the exploration challenges imposed on it with better quality airborne multi parameter geophysical data.