Director of the National Geophysical Research Institute Hyderabad Prof Mrinal K Sen on Monday threw light on “Geophysical investigation of impact craters” while speaking as chief guest at Wadia Institute of Himalayan Geology while delivering the Prof JB Auden Memorial lecture.
Giving example of two impact craters such as Shiva, Chicxulub and Boltysh depressions, he said, “They are among the most productive hydrocarbon sites on earth. Donofrio, 1998 recorded 17 confirmed impact structures occurring in petroliferous areas of North America, nine of which are being exploited for commercial hydrocarbons. The impact cratering process results in unique structures and extensive fracturing and brecciation of the target rock, which can be conducive to hydrocarbon accumulation.”
Prof Sen concluded his speech saying that the geophysical investigations at impact structures reveal that a variety of signatures can result from the impact induced physical changes in targets rocks. As a result, attempts at identifying a structure solely on the basis of geophysical evidence can be ambiguous. Nevertheless, from the increasing amount of data that exist over the terrestrial impact craters, some broad conclusions can be drawn based on the geophysical response of a suspected impact structure.
Geophysical surveys are essential for detailed mapping of impact structures.