A Note on Geophysical Mapping of the Granulite Terranes Surrounding the Godavari Basin

Regional gravity and aeromagnetic data over the Godavari basin and the adjoining region show distinct signatures of granulite terranes of Karimnagar and Bhopalpatnam areas. The Karimnagar Granulite Terrane (KGT) showing up as a thin (about 10-15 km wide) North-South belt near Khammam, widens to about 100 km near Warangal and extends through Karimnagar, Adilabad and beyond up to Wardha in a NW-SE direction, parallel to the Godavari basin. The Bhopalpatnam Granulite Terrane (BGT) appears as a 10 km wide linear belt on the eastern side of the basin. The Eastern Ghat Granulite Terrane (EGT), which occupies a vast area along the east coast of India, also possesses similar characteristic features within the study area. About 15 krn east of Hyderabad, a North-South linear belt showing characteristic signatures of granulites could be identified from the aeromagnetic image. This belt, named as the Hyderabad Granulite Terrane (HGT) is about 25 km wide and joins the KGT near Karimnagar. These granulite terranes show higher values of magnetic susceptibility and density (except that of HGT).