Airborne Magnetic Lineament, Groundwater Potentiality and Basement Structures in S-E Part of Vindhyan Basin

Airborne total intensity magnetic survey flown at a height of approximately 152 m in central India has delineated several linear magnetic anomalies of 200-400 nT aligned together to form a large magnetic lineament approximately 1 km wide and 100 km long. The nature of magnetic anomalies suggest the lineament to be a fracture zone with basic intrusives at places. Magnetic and resistivity surveys on ground provide large magnetic (600-800 nT) and low resistivity anomalies along this lineament suggesting a fracture zone with basic intrusive rocks at places and very good groundwater potentiality along it.. Existing wells close to the lineament yield good amount of water, while those away from it show poor yield. Water table contour map of the area shows contours parallel to the lineament indicating pumping of more water from this zone causing lateral flow of groundwater.

This lineament does not find reflection in the ground gravity survey; instead it delineated some second order small dome and basin structures around Damoh and Jabera which are not recorded in the airborne total intensity map referred to above. This suggests that while linear features are better reflected in the airborne magnetic surveys small-scale three-dimensional basement structures are better reflected in the ground gravity surveys. This indicates the need for an integrated airborne and ground exploration programme for delineating subsurface structures/tectonics and to quickly assess the groundwater resources of a region.