Palaeofloral Investigation Based on Morphotaxonomy, Palynomorphs, Biomarkers and Stable Isotope from Lalmatia Coal Mine of Rajmahal Lower Gondwana Basin, Godda District, Jharkhand: An Inclusive Empirical Study
S. Suresh Kumar Pillai, Runcie Paul Mathews, Srikanta Murthy, Shreerup Goswami, Shailesh Agrawal, Mrutyunjaya Sahoo, Ranjit Kumar Singh
Abstract
Abstract A rich Glossopteris dominated plant fossils assemblage is recovered from the Barakar Formation of Lalmatia coal mine, Hura coalfield of Rajmahal Basin, Godda district, Jharkhand, India. The assemblage includes Glossopteris, Gangamopteris and Noeggerathiopsis (leaf forms) along with Vertebraria (root form). There are 4 genera and 14 species of megafossils in the collection, which includes 10 species of Glossopteris, two species of Gangamopteris and one species of Noeggerathiopsis and Vertebraria each. The flora, although similar to that of the Barakar Formation of the Damodar Basin complex, exhibit unique characteristics and is of Artinskian to Kungurian in age. The palynoassemblage recovered in the section reveals the dominance of genus Scheuringipollenites and sub–dominance of Faunipollenites (=Protohaploxypinus) along with Parasaccites, Potonieisporites, Barakarites, Plicatipollenites, Striomonosaccites, Striatopodocarpites, Crescentipollenites, Verticipollenites, Rhizomaspora, Distriatites, Primuspollenites, Striasulcites, Lunatisporites, Guttulapollenites, Platysaccus, Microfoveolatispora, Micro-baculispora, Horriditriletes, Tiwariasporis and Weylandites, which demonstrates an early Permian age (Artinskian). The palyno-assemblage indicates that the sediments belong to the lower part of the Barakar Formation. Biomarker analysis suggests varying organic matter input during the deposition of the studied sequence. Diterpane compounds and megafossil evidences suggest Glossopteris were the dominant flora along with conifers. Bacterial alteration of the organic matter is inferred from the hopane compounds. The δ13C value of organic matter associated with the carbonaceous shale directly corroborates with the typical δ13C values of the Permian time and is suggestive of warm and humid climatic conditions.