Mineralogical characterization and transport pathways of dune sand using Landsat TM data, Wahiba Sand Sea, Sultanate of Oman

Sand samples and Landsat imagery were used to characterize the spatial distribution of sand mineralogy, and to evaluate potential sources and transport pathways of sediment in the Wahiba Sand Sea in the Sultanate of Oman. Landsat TM data were useful in the geomorphic interpretation of a desert, aeolian environment to distinguish the mineralogies found in the Wahiba area, and in extending the identification of sand mineralogy beyond the point-specific grid produced from field sampling. The Wahiba Sand Sea has been previously divided into upper (north and higher in elevation) and lower (south and lower in elevation) portions, based on dune morphology. Large-scale spatial distributions of mineral composition follow a similar pattern to that of the geomorphic regions within the dune field. Field and Landsat TM data suggests the upper Wahiba is comprised of well-mixed carbonate and quartz sand with some areas of significant mafic content. Surface sand in the eastern and western margins of the upper Wahiba originate from the lower Wahiba and from local wadis. Sand in the lower Wahiba was likely derived from southern sabkhas and the coastal area and is quartz-rich with isolated locations of carbonate-rich sand. We suggest that these carbonate-rich patches in the lower Wahiba were derived from reworked aeolianites (lithofied sand dunes) which underlie most of the sand sea, and not directly from the coast, as previously reported. (C) 1999 Elsevier Science B.V. All rights reserved.