Abstract

Much of the abundant Precambrian sedimentary record of India appears to have been deposited in shallow coastal environments. One example of this, the Ramgundam Sandstone, is a moderately thick (120 m) unit composed of lens-shaped bodies of arkosic sandstone and interbedded sandstone and shale. Outcrops are mostly limited to small quarry pits, but sufficient exposures are present to show major bedding characteristics. Principal components are wave-built bars and interbar fillings. The bars, 1 to 5 m thick and tens of meters wide, contain laterally accreting sets of trough cross-bedded sandstone. Interbar deposits are composed of horizontal to subhorizontal beds of ripple-laminated sandstones and interlaminated shales, siltstone, and sandstone containing wavy, lenticular, and flaser laminae. Shallow water, subaerial exposure, and probable tidal fluctuations are recorded on the bar surfaces by flat-topped ripples and interference ripples, water-recession marks and desiccation cracks.

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