Petrography and heavy minerals analysis for recognition of the depositional history of the Wahiba Sand Sea, Sultanate of Oman

The study deals with the microscopic investigation of the Wahiba sand dunes to deduce the depositional history and the provenance. Petrographic investigation reveals that Wahiba sands consist mainly of fine to very fine-grained and moderately
well-sorted siliciclastic-carbonate components. Sand components consist of quartz, feldspar (microcline and plagioclase), fossils (benthic foraminifera and shell fragments), and several kinds of rock fragments; sedimentary, igneous, and metamorphic. The
heavy minerals recognized in Wahiba sand dunes include opaque iron minerals, augite, hornblende, epidote, zircon, tourmaline, rutile, garnet, kyanite, olivine, biotite, and chlorite, in addition to weathered carbonate minerals. These kinds of heavy minerals
indicate that Wahiba dunes are derived mainly from igneous, metamorphic, and sedimentary sources. Ancient wadis brought ambiguous amounts of detrital materials from the steep mountains to be deposited in the marine shelf environment, then mixed
with recent marine deposits and reworked by currents and waves. When sea level dropped in the Late Quaternary, these continental shelf deposits were subjected to subaerial processes where winds expedited the transport of the mixed siliciclastic carbonate sediments to form aeolianites near the coast. These aeolianites have been recycled again by the complex wind processes and mixed with recent detrital materials. The latter originated from the steep mountains in the northeast and west to
form the northern Wahiba dunes.