Late Archaean tidalites from western margin of Chitradurga greenstone belt, southern India

•First report of Late Archaean tidal sediments from India.•Tidal sedimentation in 2.8–2.6 Ga old Chitradurga greenstone belt, India.•Neap–spring cyclicity in a Late Archaean semidiurnal tidal system.

Tidalites are preserved within a metavolcano-sedimentary succession of the Late Archaean Bababudan Group (Dharwar Supergroup) along the western boundary of the NNW-SSE trending Chitradurga greenstone belt, West Dharwar Craton, southern India. These may represent the oldest record of tidal processes in peninsular India. Millimetre thick sand–mud alternations, bidirectional cross-strata, mudstone-draped sandy foresets, reactivation surfaces indicating time–velocity asymmetry, sigmoidal cross-strata and mudstone draped flaser/lenticular bedding are displayed by the sandstone mudstone heterolithic facies in the upper part of the Bababudan succession, together implying a tidal depositional system. Thick–thin pairs of rhythmic foreset bundles correspond to neap–spring tidal cycles within a semidiurnal tidal system. Development of the studied coastal sediments suggests formation of stable platform along the western margin of the late Archaean Chitradurga greenstone belt.