CSIR NET June 2016 Q81: Stratigraphy
The Marwar Supergroup of Rajasthan (~750-560 Ma) spans the Cryogenian-Ediacaran interval, during which the globally recognized Marinoan glaciation (~650-635 Ma) occurred and is recorded worldwide as glacial diamictites and cap carbonates.
The Marinoan glaciation is a well-dated global Neoproterozoic 'Snowball Earth' glacial event falling squarely within the 750-560 Ma depositional window of the Marwar Supergroup, making it the event most likely to be recorded in these rocks (e.g., as glacigenic deposits/cap carbonates). Option 1 is correct.
1) Correct — Marinoan glaciation (~650 Ma) falls within the given time bracket and is a recognized global stratigraphic marker. 2) Gondwanaland breakup is a much younger (Mesozoic, ~180 Ma) event, far outside this range. 3) Rodinia breakup mainly began around/before 750 Ma and is largely a precursor/boundary event rather than one recorded through this whole interval. 4) The Cambrian explosion (~541-530 Ma) postdates the upper limit (560 Ma) of the Marwar Supergroup.