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The Chattisgarh is a major Neoproterozoic cratonic basin in peninsular India, which covers
2
about 33,000 km of the Chattisgarh State with a narrow extension in Orissa. The western and
south-central part of the basin is characterized by prolific development of algal stromatolites
and mature sandstones, a characteristic stable platformal association. The geology of the
eastern part of the basin, by contrast, comprises variety of lithologies ranging from thick
wedges of conglomerates and coarse feldspathic sandstones, extensive blankets of shale and
lithographic limestone, and pyroclastics, deposited in widely varying conditions of sediment
input, reworking, transport, and bathymetry. The sedimentary rocks are gently dipping to
subhorizontal, except near major faults, and unconformably overlie The age of the succession
is not very precisely constrained. Kruezer et al. (1977) suggested a K-Ar date of 700-750 Ma
for the basal part of the succession, whereas Schnitzer (1971) proposed that the succession
may range between 800 and 1100 Ma in age.

11. Review and status of research and development in the subject(Max. 500 words):
11.1 International Status:
The permanent rise of atmospheric oxygen to significant concentrations 2.1-2.4 Ga ago during
the Great Oxidation Event (GOE) was initially reported by (Roscoe, 1976) and remained more
or less constant for almost 2 Ga before they increased to modern values at late Neoproterozoic
(Lyons et al., 2014 and references therein). Throughout the Proterozoic, it is assumed that the
marine oxygen concentrations were likely to have been low and that euxinic- (Canfield, 1998)
or iron- rich anoxic conditions prevailed in the oceans with euxinia largely limited to
biologically productive continental shelves and restricted marginal basins (Scott et al., 2008;
Lyons et al., 2009; Planavsky et al., 2011). Holland (2006) proposed that between 3.85–2.45
Ga surface waters of the oceans were still anoxic but between 2.45-0.54 Ga ago surface ocean
waters were mildly oxygenated but the deep oceans remained mostly anoxic. The amount of
dissolved O2 in the Earth’s oceans at the beginning or before the GOE (~ 2.4-2.3 Ga) remains
poorly understood. Anbar & Knoll (2002) proposed that for much of the Proterozoic (2500 -
543 Ma), the oceans were moderately oxic at the surface and sulfidic at depth. Ostrander et
al. (2019) similarly argued for the regional scale episodic accumulation of dissolved oxygen
in the oceans on continental shelves and margins during or before the GOE, but the extent of
this oxygenation remains unclear. To understand the early oxygenation history of the
atmosphere and ocean geochemical proxies (iron, molybdenium, calcium, chromium; carbon,
oxygen, and sulphur isotope data, trace element abundances and biomarkers) of the marine
carbonates from the ancient basins around the world have been studied. Still, current
understanding of redox conditions and the oxygen cycle in the Proterozoic oceans is
insufficient and the seawater chemistry of Palaeoproterozoic and Mesoproterozoic carbonate
facies still remains poorly understood and is limited to reports from Australia (Kah et al.,
2004), Brazil (Gilleaudeau et al., 2016), Canada (Kah et al., 2001; Kah et al., 2004;
Gilleaudeau et al., 2016; Fralick et al., 2017), China (Guo et al., 2015; Huang et al., 2015;
Luo et al., 2015), Mauretania (Kah et al., 2012; Gilleaudeau et al., 2016) and Russia (Bartley
et al., 2007; Gilleaudeau et al., 2016).

11.2 National Status:
The Indian subcontinent hosts a number of sedimentary basins of Proterozoic time majority
of which hosts undeformed and unmetamorphosed sedimentary sequences that are marine and
there- fore likely to hold clues to ancient climatic evolution of the Planet during this period.
But there exist only a handful of studies that attempt to uncover the evidences for Proterozoic
events from the carbonate formations in these basins (e.g., Ray et al. 2003; Mohanty et al.
2015; Ansari et al. 2018; George et al. 2018). Most of the data have come from the Vindhyan
Basin which is the largest Proterozoic sedimentary basin of India. Geochemical studies of the

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