Quaternary corals of Okha- An evidence of Sea level changes and environment of deposition

摘要

Three exposed well section have been observed near Gayatri Temple, Pir Baba Ki Darga Mithapur, and Old Aramda Railway Station, Aramda. All the section consists of three-four units, including coral frame stone, massive corals i.e. Favia, branching coral i.e. Acropora andalgal frame stone. Rudstone mainly algal debris is present in two sections. Presence of Acropora, Favia, and coralline algae suggest an intertidal lagoonal to an off-shore sub tidal with above-wave-based marine high energy environment. Sediments of the above well-sections belong to coral-algal lithofacies group. Geological succession, order of superposition and associated other information, which have been observations during this study area, indicates that, the period involved in the formation of the discontinuity represented by coral-algal lithofacies group should be Late-Middle Holocene (10,000-7,000 years). Discontinuity in the form of this facies also represents a regressive phase of the sea level in the study area for from 11,700 to the recent.