CLIMATIC CONDITION AND TECTONIC EVOLUTIONARY HISTORY OF PERMO-CARBONIFEROUS GONDWANAN BASINS IN NORTHEASTERN INDIAN CRATON

The Permo-Carboniferous Gondwanan basins in northeastern Indian craton have been understudied regarding their evolution and geo-tectonic settings. Previous studies revealed multiple possible sediment provinces based on petrological, mineralogical, and geochronological data intending to imply their possible source areas. Here we approach with a different method, trying to understand first, the climatic condition, as the related basins were receiving sediments during a period of deglaciation along with predicting sediment flow direction based on modelling using detailed lithological logs from drill hole data from three basins, and geophysical gravity data from previous surveys. Whole-rock geochemistry of 10 samples from these basins indicate a source from igneous rocks in a passive margin condition, that have a similar trend to Post Archean Australian Shale (PASS) and North American Shale Composite (NASC) standards. Lithological modelling of the three basins indicates rifting during sedimentation. Sediment thickness data supports sediment flow direction mostly from the northwest. Lastly gravimetric data collected from Bureau of Gravimetrique International (BGI) indicates, ~20-100MGal and -40-20MGal for Bouguer and free air anomaly respectively. These values refute with our area of interest in the northeastern part of the Indian craton, compared to the rest of Bengal basin, particularly where Gondwanan rocks are present over a shallower basement. Combining all these information along with upcoming geochronological analyses are expected to provide a better understanding about not only how these individual basins formed but also the history of their sedimentation and tectonic evolution.