Megafloral zonation of Permian-Triassic sequence in the Kamthi Formation, Talcher Coalfield, Orissa
DOI:
https://doi.org/10.54991/jop.1997.1319Keywords:
Megafloral zonation, Kamthi formation, Permian-Triassic Boundary, Talcher Coalfield, IndiaAbstract
The Kamthi Formation exposed in the west-central part of Talcher Coalfield is divisible into a Lower and an Upper Member. Megafloral assemblage (Assemblage Zone-I) of the Lower Member is dominated by Glossopteris in association with Trizygia, Vertebraria and Pseudoctenis. The Upper Member consists of two distinct sets of lithounits, viz., lower and upper beds. Assemblage Zone-II found in the lower beds of Upper Member is characterised by preponderance of Glossopteris; associated elements are: Cyclodendron, Phyllotheca, Stellotheca, Trizygia, Sphenophyllum, Raniganjia, Schizoneura, Dizeugotheca, Neomariopteris, Damudopteris, Surangephyllum, Handapaphyllum, various glossopterid fructifications, scale leaves, etc. The Assemblage Zone-III also from the lower beds of Upper Member is dominated by Glossopteris; associated elements are equisetaceous stems and Neomariopteris. However, the presence of Lepidopteris and ?Dicroidium distinguishes Assemblage Zone-III. Assemblage Zone-IV from the upper beds of Upper Member is characterised by abundance of Dicroidium, in association with Lepidopteris, Elatocladus, Yabiella and Desmiophyllum. On the basis of megafloral assemblages, it has been derived that Permian-Triassic Boundary (PTB) in the Talcher Coalfield lies somewhere in the lower beds of the Upper Member of Kamthi formation.