Upper Pennsylvanian Age of the Lower Talchir Formation in the Wardha Basin, Central India, Based on Guide Palynomorphs Present in Radiometrically-Dated Palynozonations in South America, Africa, and Australia

Abstract

The age of the Talchir Formation corresponding to the lower part of the Gondwana (Permo-Carboniferous) Sequence in India is revised in the light of palynostratigraphic data associated with radiometric dating generated in Gondwana. New data was generated from seven samples of the Talchir Formation obtained from Well 131 located in the Penganga area of Wardha Valley Coalfield (Maharashtra State, central India). Two assemblages were demarcated based on the stratigraphic distribution of 63 species of spores (23 taxa), pollen grains (36 taxa) and phytoplankton. Palynoassociation I (PI) recognized in the two basal samples yielded few Punctatisporites spores and monosaccate pollen grains. Palynoassociation II (PII) is demarcated in the overlying three samples characterized by spores and pollen grains that are more diversified and abundant than in the other two samples. Several taxa (Concavissimisporites grumulus, Converrucosisporites confluens, Cyclogranisporites gondwanensis, Verrucosisporites andersonii, Latusipollenites quadrisaccatus, Marsupipollenites striatus, Pakhapites fusus, Striatoabieites multistriatus, Vittatina subsaccata, V. vittifera) are shared with palynozones radiometrically constrained to the latest Pennsylvanian-early Cisuralian in Argentina, Brazil, Africa and Australia. Therefore, we propose a Kasimovian to Ghezelian / Asselian age for the PI and PII associations of the Talchir Formation, and a correlation with the Potonieisporites neglectus and Plicatipollenites gondwanensis Zones of Tiwari & Tripathi respectively, attributed to the early Permian. This approach significantly improves the stratigraphic correlations of the Indian palynozones in Gondwana.