Early permian macro and miofloral diversity from Singrauli coalfield, son-mahanadi Basin, India

Abstract

Mega and miofloral diversity of the coal bearing sequences of the Barakar Formation of the Block-B and Nigahi collieries, Singrauli Coalfield has been studied in detail to infer the palaeofloristics, age assessment and palaeoenvironment. A diverse glossopterid assemblage has been recorded from a sequence of Block B colliery, whereas from the Nigahi colliery no megafossil is reported. The assemblage comprises of Gangamopteris, Glossopteris and equisetalean axes. The genus Glossopteris dominates the assemblage and is represented by ten species, namely, G. arberi, G. communis, G. gigas, G. indica, G. longicaulis, G. mohudaensis, G. nautiyalii, G. raniganjensis, G. spatulata, and Glossopteris species. The genus Gangamopteris is represented by five species namely, G. angustifolia, G. cyclopteroides, G. karharbariensis, G. major and Gangamopteris sp. Interestingly, the procured fossil leaves of Glossopteris and Gangamopteris are fairly large and broad as evidenced by the abundance of Glossopteris gigas and Gangamopteris cyclopteroides species in the assemblage suggesting the existence of low light or the shady conditions in and around the vegetated area. The palynological study has revealed two palynoassemblages, Palynoassemblage I and Palynoassemblage II from the Barakar sediments of Block B and Nigahi collieries respectively. Both the assemblages reveals the dominance of non-striate bisaccate pollen grains Scheuringipollenites and sub dominance of striate bisaccate pollens Faunipollenites followed by Parasaccites, Plicatipollenites, Potonieisporites, Densipollenites, Divarisaccites, striate bisaccate pollen grains viz. Striatopodocarpites, Crescentipollenites and spore Rhizomaspora. The dominance of palynomorph Scheuringipollenites barakarensis suggests a late early Permian (Artinskian) age to the studied coal bearing sequences of Block-B and Nigahi collieries which is also substantiated by the diverse occurrence of Gangamopteris in the mega plant assemblage. © 2019 Palaeontological Society Of India. All rights reserved.