Palaeofloristics of Lower Gondwana Exposure near Kumunda Village, Angul District, Talcher Basin, Odisha, India: A Comprehensive Study on Megafloral and Palynofloral Assemblages

Megafloristics and palynology of a fossiliferous section near Kumunda Village, Angul district, Talcher Basin, Odisha have been studied. The exposure is located at 20 degrees 58(')32('') N latitude and 85 degrees 01(')45('') E longitude. The megafloral assemblage of the investigated section comprises Glossopteris, Vertebraria indica (Glossopteridales); Trizygia speciosa (Sphenophyllales); Schizoneura gondwanensis, Equicetaceous stems (Equisetales) and Neomariopteris hughesii (Filicales) along with stem casts. The genus Glossopteris dominates the assemblage with 20 different species and more than 60% in occurrence. The specimens are preserved as both impressions and compressions on compact, fine-grained carbonaceous shales. In addition, two distinct palynofloral assemblages have been recognized in this section. Palynoassemblage-I is characterized by the predominance of Striatopodocarpites spp. and Faunipollenites spp., while Palynoassemblage-II is dominated by Striatopodocarpites spp. and Faunipollenites spp. along with Densipollenites spp. The Palynoassemblages I and II correlate with Striatopodocarpites-Faunipollenites assemblage zone and Striatopodocarpites-Densipollenites assemblage zone respectively of the Late Permian Raniganj Formation in the Damodar Basin. The presence of key species viz., Densipollenites magnicorpus, Falcisporites nuthallensis, Strotersporites spp., Lunatisporites pellucidus, Guttulapollenites hannonicus, Corisaccites alutus, Weylandites lucifer and Hamiapollenites bifurcates in these palynoassemblages assign their affinity to the Late Permian. The present palynological investigations have identified the presence of Raniganj/Lower Kamthi (Late Permian) sediments exposed near Kumunda village, which is lithologically designated as Barakar Formation (Early Permian). Hence a precise and more thorough sampling for palynological studies and detailed geological mapping of this area should be attempted to delimit more accurately the distribution of the different Lower Gondwana formations in this investigated area of this basin. The rich diversity of Glossopteris leaves in the fine sediments infers seasonal falling and favourable conditions for plant growth with warm, humid (very high), temperate climate with intermittent rainfall during this period in Talcher Basin.