TIDAL CYCLICITY IN LOWER BHANDER SANDSTONE, MAIHAR, MADHYA-PRADESH

The Upper Proterozoic Lower Bhander Sandstone, occupying a major part of the Tamasa valley at Maihar, has been thought to be deposited in a tidal flat-lagoon complex in an intertidal to supratidal environment, dominated by ebb and flood tides. A tidal bundle (a medium grained thi cker sandstone unit and a thinner siltstone bed) is thought to bear th e imprint of velocity and discharge associated with each tidal current as reflected in the thickness of the layers. Thickness data pertainin g to 155 tidal bundles recognized in the exposures have been analysed using techniques of Smoothing, Autocorrelation and Fourier filtering, to reveal whether or not any tidal cyclicity existed. The results ampl y support not only the presence of alternating high spring-neap-low sp ring semi-lunar cycles, but a dominant periodicity of 32 bundles corre sponding to 16 semi-lunar days.