EARLY-REPLACEMENT DOLOMITIZATION AND DEEP-BURIAL MODIFICATION AND STABILIZATION - A CASE-STUDY FROM THE LATE PRECAMBRIAN OF THE ZAWAR AREA, RAJASTHAN (INDIA)

The dolomites of Zawar area belong to the late Precambrian upper Aravalli Supergroup. The initial dolomitization process was initiated by seawater through tidal pumping in the tidal flat environment. It is evidenced by low REE content and deltaC-13 values (+ 1.12 to + 2.85 o/oo PDB) and subsequent burial dolomitization is shown by xenotopic texture, depletion in Na and Sr content and lighter oxygen isotopic composition. The early seawater and later burial dolomitization processes played the major roles in the formation of carbonates of the Precambrian upper Aravalli Supergroup.