ELSEVIER Precambrian Research 84 (1997) 63-81

Despite deformation and metamorphism the 2.3 Ga fine-grained siliciclastic Chaibasa Formation of eastern India locally retains an excellent record of sandwave migration under the influence of tides and storms within a precursor sandstone facies in a largely subtidal setting and provides a rare opportunity to detect idal periodicities. In the finer facies locally preserved, minor features provide glimpses of the depositional mechanisms and settings. The silt-dominated precursor heterolithic (silt-mud) facies contain numerous lides and slumps and was formed on a relatively steep slope between the fairweather and storm wave bases. The shale facies formed in a deeper setting beneath the wave base. Earthquakes occasionally have interrupted normal sedimentation a d massflow products are present in all the facies, but with increasing frequency within the finer facies. The sandstone facies units, which were emplaced uring repeated lowstands, were first subjected to progradation and subsequently drowned, in an overall transgression trend. © 1997 Elsevier Science B.V