Petrography and heavy minerals as tools for reconstruction of provenance and depositional environment of Bhuban sandstones in Aizawl, Mizoram
Authors: J. Lalnunmawia, Ch. Vabeihmo, H. Lalremruatsanga
Number of views: 367
Mizoram is entirely covered by sedimentary successions of variable sand-silt-shale ratio. The predominating bed comprises of Surma Group of rocks, and Bhuban Formation being the dominating strata. The present study area of eastern anticlinal limbs of the Aizawl city are made up of thick succession of Bhuban Formation of Surma Group dipping towards east with strike of approximately N-S direction. The present research aims to find out the nature of provenance and the environment of deposition of the sediments on the bases of petrography of the sandstones and heavy minerals present. The petrography indicate presence of quartz, lithic fragments, feldspar, micas, opaque minerals bind together by siliceous, ferruginous and carbonate cements. The heavy minerals comprises of garnet, augite, zircon, rutile, staurolite, sillimanite, kyanite, hypersthene, hornblende, chlorite, tourmaline and apatite. It is found that the sediments of sandstones are derived most probably from the Himalayan Orogenic fold belt and the Indo-Burmese Collision Zones, and the sediments being transported by turbidity current and deposited in deltaic to shallow marine environment.