Palynofloral and Palynofacies Evidences and its Implication on the Depositional Environment from Wardha Valley Coalfield, Maharashtra

The palynological and palynofacies studies have been undertaken on the sub-surface sediments of borehole AK-19 from Asthona area of the Wardha coalfield, India. The present investigation has revealed the existence of two distinct palynological assemblages, which have been designated as palynoassemblage – I and II respectively. The former, has shown a predominance of monosaccates viz., Parasaccites, Plicatipollenites, Potonieisporites , and Crucisaccites , whereas, the latter is characterized by the dominance of striate bisaccates such as Faunipollenites and subdominance of non-striate bisaccate Scheuringipollenites along with other striate forms such as Striatopodocarpites, Crescentipollenites , and Rhizomaspora . The other genera recorded mainly includes Parasaccites, Indotriradites , and Callumispora , which suggests that primarily herbaceous and the arborescent plants where luxuriantly growing in the forest with the prevalence of hygrophilous and mesophilous environmental conditions. The recovered palynoassemblages are governed mainly by the gymnosperms such as glossopterids, conifers, and cordaites, etc., flourished in near shore areas in riverine, lacustrine conditions as well as in large swamps and marshy habitat with the prevalence of initially cold climatic conditions (Palynoassemblage-I) which later on became temperate (Palynoassemblage-II). The present palynoassemblages have a closer affiliation with the known early Permian palynofloras of other Gondwana basins of India such as Umrer and Kamthi coalfields and Godavari, Damodar, Son-Mahanadi and Satpura basins. It can also be tentatively correlated with the early Permian palynoassemblages ofo South America, Antarctica, Australia, Africa and Salt range of Pakistan. Hence, Artinskian and Kungurian age (early Permian) has been assigned to the studied palynoassemblages respectively. The study of organic matter has revealed three distinct palynofacies (I-III) which are characterized by the dominance of palynomorphs (Palynofacies-I), phytoclasts (Palynofacies-II) and biodegraded organic matter (Palynofacies-III) respectively. Palynofacies-I-III reflects the proximal fresh water settings; oxidizing fluvio-deltaic near shore conditions and distal dysoxic waterlogged settings respectively. Palynofacies-I and II represent the oxidizing conditions while Palynofacies-III represents the reducing conditions.