Tectono-Provenance of Bhuj Member Sandstone (Upper Tithonian-Lower Albian) Kachchh, Gujarat, India

摘要

The studied Bhuj Member Sandstone is the youngest lithostratigraphic unit of the Kachchh Mesozoic Basin of probably Upper Tithonian - Lower Albian age and is considered to be deposited under shallow marine coastline environment by Shukla, U.k. and Singh, I.B.. (1990). The sandstones are medium to coarse grained and poorly sorted to moderately well sorted. The sancTgrains are subangular to subrounded and show low to medium sphericity. The constituent mineral grains are of various types of quartz followed by feldspar, rock fragments, mica and heavy minerals derived from Aravalli range and Nagarparkar massif. Diagenetic modification suggests porosity reduction is mainly due to early stage of mechanical compaction and subsequent pervasive iron oxide cement followed by late stage authigenic kaolinization in the secondary pore spaces. Compaction is mainly mechanical with a depth of burial in the range of 1800-3127 feet. The plots of petrofacies in Qt-F-L, Qm-F-Lt, Qp-Lv-Ls and Qm-P-K ternary diagrams suggest that sediments were derived mainly from craton interior in a rifted continental margin basin setting.