Palynostratigraphy of lower Gondwana sediments in Godawari graben, Andhra Pradesh, India

Abstract

The subsurface Lower Gondwana sediments in Ramagundam and Ramakrishnapuram areas of Godavari Graben, Andhra Pradesh comprise Talchir to Barren Measures formations present in two bore-holes, viz., GRK I and GGK 20. The distribution of palynofossils in time and space suggests the occurrence of six palynozones: Palynozone 1marked by the dominance of radial monosaccates (chiefly Parasaccites) representing the Talchir mioflora; Palynozone 2-characterised by the incoming of Callumispora in addition to radial monosaccates representing Lower Karharbari mioflora; Palynozone 3-representing the Upper Karharbari mioflora marked by the dominance of radial monosaccates associated with low nonstriate-disaccates; Palynozone 4-nonstriate-disaccates (chiefly Scheuringipollenites) attaining overall dominance representing the Lower Barakar palynoflora and containing the productive coal seams of the area; Palynozone 5- striate-disaccate pollen (chiefly Faunipollenites) attaining overall dominance and representing the Upper Barakar palynoflora; Palynozone 6-characterised by the association of srriate-disaccate pollen and Densipollenites representing the youngest assemblage in the present investigation. These assemblages have been compared with known palynofloras. The existence of Karharbari and Barren Measures formations in Ramagundam and Ramakrishnapuram areas has been established with palynological evidence.