Palynostratigraphy and correlation of the coal bearing Gondwana sediments in the Kothagudem sub basin of the Godavari Graben, South India

Abstract

The present investigation deals with the palynology of five sections from the Kothagudem sub–basin of the Godavari Graben, India to unravel the biostratigraphy and palaeovegetation. The palynological analysis in the five sections of Rampur, Hemchandrapuram and Kothagudem areas revealed the presence of Karharbari (Palynozone–I), lower Barakar (Palynozone–II) and Raniganj (Palynozone–III) equivalent palynofloras in lithologically designated Barakar Formation. Palynozone–I is dominated by cordaitalean radial monosaccate pollen grains (Parasaccites spp., Plicatipollenites spp.) and trilete spores (Callumispora spp.)which represent colder climatic conditions. Palynozone–II is chiefly dominated by non–striate bisaccate (Scheuringipollenites spp. and Ibisporites spp.) and striate bisaccate (Faunipollenites spp., Striatopodocarpites spp.) grains of conifer and glossopterid origin indicating presence of peat–forming plants and conducive climatic condition for the coal formation. Palynozone–III is mainly dominated by striate bisaccate pollen grains of glossopterid origin along with conifer (Faunipollenites spp., Striatopodocarpites spp., Crescentipollenites spp.) and peltasperm (Falcisporites spp., Chordasporites spp.) pollen grains representing hot and humid conditions. Palynozone–III is characterized by the dominance of striate bisaccate taxa along with stratigraphically significant palynomorphs (Corisaccites sp., Guttulapollenites sp., Lunatisporites sp., Chordasporites sp., Falcisporites sp., etc.). On the basis of palynofloral composition Palynozone–I, II and III have been assigned to the Sakmarian (upper Karharbari), Artinskian (lower Barakar) and Lopingian (Late Permian) age respectively.