Late Pennsylvanian and Early Cisuralian palynofloras from the Rajmahal Basin, eastern India, and their chronological significance

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

“…They have demarcated three palynozones in the basal Talchir Formation -Potonieisporites neglectus, Plicatipollenites gondwanensis and Cannanoropollis janakii (=Parasaccites korbaensis) in stratigraphic order constrained to the early Permian based on the general dominance of monosaccates and the associated occurrence of the marine Eurydesma fauna. Murthy et al (2020) revised the age of these palynozones based on a critical analysis of the composition of these assemblage zones, their reference horizons and corresponding lithofacies and associated fossils (see Table 3 in Murthy et al, 2020) and proposed a correlation with radiometrically constrained similar assemblages across Gondwana. They established for the first time, a late Pennsylvanian age to the oldest Potonieisporites neglectus Assemblage Zone of Tiwari & Tripathi (1992) The overlying Plicatipollenites gondwanensis Assemblage Zone from the siltstones above younger boulder beds was attributed to the early Cisuralian by Murthy et al (2020) based on the first appearance of Permian marker taxa, reinforced by associated Eurydesma assemblage fauna (Lele & Makada, 1972).…”

“…Murthy et al (2020) revised the age of these palynozones based on a critical analysis of the composition of these assemblage zones, their reference horizons and corresponding lithofacies and associated fossils (see Table 3 in Murthy et al, 2020) and proposed a correlation with radiometrically constrained similar assemblages across Gondwana. They established for the first time, a late Pennsylvanian age to the oldest Potonieisporites neglectus Assemblage Zone of Tiwari & Tripathi (1992) The overlying Plicatipollenites gondwanensis Assemblage Zone from the siltstones above younger boulder beds was attributed to the early Cisuralian by Murthy et al (2020) based on the first appearance of Permian marker taxa, reinforced by associated Eurydesma assemblage fauna (Lele & Makada, 1972). Currently, despite some taxonomic revision of species yet required, several palynozones across Gondwana, calibrated with radiometric data from interbedded igneous rocks, support or improve the stratigraphic ranges of Pennsylvanian/ Permian diagnostic taxa that are present in the P. gondwanensis Zone (Fig.…”

“…Tiwari & Tripathi, 1992;Aggarwal & Jha, 2013, and their references), is required as previously highlighted in several publications (Truswell, 1980;Stephenson, 2008;Modie & Le Hérissé, 2009;di Pasquo et al, 2015di Pasquo et al, , 2021Barbolini et al, 2018). In the case of those not illustrated taxa a revision of samples of their respective works or the development of new studies to identify Pennsylvanian and Permian guide species is mandatory (see Murthy et al, 2020;di Pasquo et al, 2021). Murthy et al (2020) obtained a palynoassemblage attributed to the Potonieisporites neglectus Zone of Tiwari & Tripathi (1992) from the Lower Talchir Formation that appears below the Plicatipollenites gondwanensis Assemblage Zone bearing diagnostic Permian spores/pollen grains.…”

“…In the case of those not illustrated taxa a revision of samples of their respective works or the development of new studies to identify Pennsylvanian and Permian guide species is mandatory (see Murthy et al, 2020;di Pasquo et al, 2021). Murthy et al (2020) obtained a palynoassemblage attributed to the Potonieisporites neglectus Zone of Tiwari & Tripathi (1992) from the Lower Talchir Formation that appears below the Plicatipollenites gondwanensis Assemblage Zone bearing diagnostic Permian spores/pollen grains. An undoubted late Carboniferous age is assigned to this basal Talchir Formation by Murthy et al (2020) confirming the interpretation of Mukhopadhyay et al (2010) and few previous studies (Casshyap & Qidwai, 1974;De, 1979;Raja Rao, 1982, 1983, 1987.…”

“…Murthy et al (2020) obtained a palynoassemblage attributed to the Potonieisporites neglectus Zone of Tiwari & Tripathi (1992) from the Lower Talchir Formation that appears below the Plicatipollenites gondwanensis Assemblage Zone bearing diagnostic Permian spores/pollen grains. An undoubted late Carboniferous age is assigned to this basal Talchir Formation by Murthy et al (2020) confirming the interpretation of Mukhopadhyay et al (2010) and few previous studies (Casshyap & Qidwai, 1974;De, 1979;Raja Rao, 1982, 1983, 1987. The early Permian age given by other researchers due to the absence of characteristic late Carboniferous fossils or palynofloras likely by erosion or nondeposition of older strata (Tiwari & Tripathi, 1988Venkatachala & Tiwari, 1988;Tiwari, 1996;Vijaya, 1996;Jha et al, 2018) is discarded.…”