Plant fossils of Maitur Formation: possibly the ultimate stage of Glossopteris flora in Raniganj Coalfield, India

Abstract

The present paper deals with the plant megafossil assemblage from the Maitur Formation, the lower part of Panchet Group of rocks, unconformably overlain by coal bearing Raniganj Formation in Raniganj Coalfield, West Bengal. The plant fossils are collected from two localities exposed in Nonia Nala Section near Asansol, Burdwan District, West Bengal. The assemblages are represented by the typical elements of Glossopteris flora, viz. Trizygia speciosa, Neomariopteris hughesii. N. lobifolia, Dichotomopteris lindleyii, D. ovata, Glossopteris indica, G. tenuifolia, G. emarginata, G. angustifolia. G conspicua, G. intermedia, G. retifera, G. gopadensis, G. taeniensis, Glossopteris sp. cf. G. dhenkanalensis, one new species G. burdwanensis sp. nov., glossopterid scale-leaves and seed-like body. The age of Maitur Formation has been assigned to Early Triassic but the plant fossil assemblages are comparable with the Late Permian plant fossils of Kamthi, Pachhwara and Bijori formations in having narrow leaf forms of Glossopteris. The investigation supports the view that there is no floral break at the Raniganj-Panchet Boundary and flora of Maitur Formation in all probability represents the ultimate stage of Glossopteris flora in Raniganj Coalfield before the onset of Early Triassic Dicroidium flora in Deoli/Hirapur Formation belonging to upper part of Panchet Sequence in Raniganj Coalfield, West Bengal.