Pattern of sedimentation during the Late Paleozoic, Gondwanaland glaciation: An example from the Talchir Formation, Satpura Gondwana basin, central India

Abstract

The Talchir Formation of Permian age is the lowermost lithostratigraphic unit of the Indian Gondwana successions preserving a record of the Late Paleozoic glaciation that affected the whole Gondwanaland. The formation unconformably overlies the Precambrian basement in all the Gondwana basins of India, and marks initiation of sedimentation after a long hiatus since the Proterozoic. The Talchir Formation of the Satpura Gondwana basin of central India shows features diagnostic of deposition under glacial regime such as the presence of diamictites, boulder pavements, bedding plane striation, faceted/striated gravels, bullet-shaped clasts, dropstone, cryoturbation, etc. The Talchir strata of the Satpura basin, in addition to tidal signatures, contain marine bivalve and trace fossils. A proglacial marine environment is thus inferred for their deposition. The dominant lithologies are conglomerate, pebbly sandstone, sandstone and shale with little limestone, which can be classified into the following major facies:• matrix-supported conglomerate, • clast-supported conglomerate, • cross-stratified, channel form pebbly sandstone, • hummocky, swaley or low-angle cross-stratified pebbly and non-pebbly sandstone, • turbidite/tempestite sheet sandstone, • massive to fissile, green to black claystone with carbonate layers and nodules.The conglomerates are interpreted as deposits of a spectrum of sub-aqueous sediment gravity flows including debris flow, hyperconcentrated/concentrated density flow and grain flow. The crossstratified pebbly sandstone bodies, on the other hand, represent braidplain delta deposits of glacial outwash origin. Hummocky, swaley, low-angle cross-stratified sediment bodies were deposited by storm-generated combined flows in a shoreface setting. In contrast, the sheet sandstone bodies are products of turbidity currents and storm-induced density currents in an inner shelf setting below fair weather wave base. The claystone facies is interpreted as a product of suspension fallout from hypopycnal sediment plumes in the outer shelf domain below storm wave base. All the lithofacies described above occur repetitively in the succession. Three facies-associations have been recognized in the Talchir Formation, representing ice-contact fandelta, outwash braidplain delta and a virtually ice-free, non-deltaic open marine realm. The different marine facies of the Talchir Formation define a number of shallowing-upward packages, which are arranged in the succession with a retrogradational trend to result in an overall fining-and deepening-upward succession. The overlying coal-bearing Barakar Formation has been interpreted to have formed in a tide-wave influenced deltaic setting with a marine, prodeltaic part. The strata that are transitional between Talchir and Barakar Formations show preservation of abundant plant materials suggesting gradual warming. The three facies-associations of the Talchir Formation also point towards progressive decrease in the intensity of glacial activity, inducing changes in the paleogeography ...

Petrography and major element geochemistry of the Permo-Triassic sandstones, central India: Implications for provenance in an intracratonic pull-apart basin

“…Dominance of first-cycle detritus in the Talchir sandstones is evident from abundance of rock fragments from the Precambrian basement complex. Abundance of fresh feldspars and unstable rock fragments, presence of authigenic smectite (McKinley et al, 2003) and virtual absence of epimatrix are generally consistent with reported cold and arid climate of the Talchir period (Chakraborty and Ghosh, 2008).…”

“…During this movement, the climate changed from cold (glacial), arid (Talchir Formation) to temperate, humid (Barakar Formation), to warm, subhumid/semiarid (Denwa Formation; Ray and Chakraborty, 2002;Ghosh et al, 2004;Chakraborty and Sarkar, 2005;Ghosh et al, 2006;Chakraborty and Ghosh, 2008). Independent sedimentological evidence suggests that there had been cyclical changes in the amount of precipitation with a net warming trend during the Gondwana sedimentation (Suttner and Dutta, 1986;Ghosh et al, 1998).…”

“…In upper part of the formation, sandstones are better sorted possibly because they were much more exposed to wave reworking (Chakraborty and Ghosh, 2008). Dominance of first-cycle detritus in the Talchir sandstones is evident from abundance of rock fragments from the Precambrian basement complex.…”

Petrography and Provenance of Early Triassic Pachmarhi Formation Sandstones, Satpura Gondwana Basin, Madhya Pradesh, Central India

“…The Permo-Cretaceous Satpura Gondwana succession has been classified into seven major lithostratigraphic unit that form oldest to youngest are the Talchir, Baraker, Motur, Bijori, Pachmarhi, Denwa and Bagra formations (Figures 2 and 3, Table 1). Barring the lowermost glacio-marine and glacio-fluvial deposits, the rest of the succession largely comprises a variety of fluvial deposits with some records of fluvio-deltaic and fluvio-lacustrine sediments [11][12][13][14][15][16].…”

Morphological consequence of Gangamopteris McCoy in Glossopteris flora

“…1). The geology of the area has been carried out by many workers viz Medlicott (1873), Jones (1887), Hobson (1926), Fox (1934), Crookshank (1936), Casshyap (1973), Casshyap and Qidwai (1971), Casshyap et al (1993), Rai and Shukla (1979), Shukla and Rai (1977), Raja Rao (1983), Peters and Singh (2001), Ghosh et al (2001), Ray and Chakraborty (2002) Singh and Shukla (2004), Ghosh et al (2004), Chakroborty and Ghosh (2005) and Chakraborty and Ghosh (2008).…”