A Comparative Geophysical Study of Major Basins in the Pranhita–Godavari Rift, India and Rio Grande Rift, USA

ABSTRACT In this study, we compare and contrast two major sub-basins in the Pranhita-Godavari rift in eastern India (Chintalapudi subbasin) and the Rio Grande rift in the western United States (Albuquerque basin) using bouguer gravity data analysis and integrated profile modeling constrained with seismic, drilling, and geological data. The Chintalapudi sub-basin formed during the break-up of Gondwana around 350 Ma, while the Albuquerque basin formed much later (30–35 Ma) in the interior of North America approximately synchronous with extension in the Basin and Range province. The Chintalapudi sub-basin is narrow and deep; and associated with a −60 mGal (low) gravity anomaly that is mostly due to Gondwana fluvial sediments of late Carboniferous (~350 Ma) to early Cretaceous age (~120 Ma). The negative gravity anomaly associated with the Albuquerque basin is −55 mGals (low) and the Cenozoic sediments were deposited on Mesozoic and Palaeozoic strata with Precambrian crystalline rocks being exposed along the basin flanks. This sub-basin is wide and shallow. Major faults which bound these basins were delineated by gravity modeling that integrated all of the available constraints, and the average depth to the basement at the basin centers calculated from gravity modeling is 4–5 km. However, for Chintalapudi sub-basin, if the residual gravity anamoly is considered, it may be reduced to about 3.5 km.