Mapping the geochemistry of the northern Rub' Al Khali using multispectral remote sensing techniques

Abstract

Spatial variations in sand sea geochemistry relate to mixing of different sediment sources and to variations in weathering. Due to problems of accessibility, adequate spatial coverage cannot be achieved using field surveys alone. However, maps of geochemical composition produced from remotely sensed data can be calibrated against limited field data and the results extrapolated over large, inaccessible areas. This technique is applied to part of the Rub' Al Khali in the northern United Arab Emirates. Trend surface analysis of the results suggests that the sand sea at this location can be modelled as an east-west mixing zone of two spectral components: terrestrial reddened quartz sands and marine carbonate sands. Optical dating of these sediments suggests that dune emplacement occurred rapidly around 10 ka BP, when sea level was rising rapidly. The spatial distribution of mineralogical components suggests that this phase of dune emplacement resulted from coastal dune sands being driven inland during marine transgression, thereby becoming mixed with rubified terrestrial sands.

A multi-proxy analysis of the Holocene humid phase from the United Arab Emirates and its implications for southeast Arabia's Neolithic populations

“…Fe-rich quartz grains, derived from the Arabian continental interior, are a third major component of the region"s dune sands (ElSayed, 1999;White et al, 2001;Garzanti et al, 2003;Farrant et al, 2012).…”

Holocene vegetation dynamics in the northeastern Rub' al‐Khali desert, Arabian Peninsula: a phytolith, pollen and carbon isotope study

“…JOURNAL OF QUATERNARY SCIENCE Rainfall is characteristically low ( $120 mm), but higher than most other places in the UAE, and there is a strong precipitation gradient across the region between the Ru'us al Jibal ( $140 mm) and Dubai ( $80 mm) but there is considerable interannual variability. The wind regime is complex, with 52% of sand-moving winds blowing from the west and northwest, driven by the Shamal, and 28% of sand-moving winds blowing from the south-east (Goudie et al, 2000a;White et al, 2001).…”

“…The morphology, provenance and origin of the dunes in this part of the Arabian Peninsula are controversial and complex (for details see White et al, 2001;Glennie, 1998). Glennie (1991Glennie ( , 1998 maps these dunes as deflated megalinear dunes, formed initially by winds blowing from SW to NE.…”

“…The largest of these is the Rub' al-Khali, the Empty Quarter of Arabia, the world's largest erg (sand sea), covering approximately 600 000 km 2 (Wilson, 1973;White et al, 2001). At present there are no permanent lakes in the Arabian Peninsula as potential annual evaporation exceeds inputs of precipitation and run-off.…”

Developing a framework of Quaternary dune accumulation in the northern Rub' al-Khali, Arabia

“…One such source of palaeoclimatic information are the Quaternary sediments that occupy the Rub' al-Khali basin. This region (Figure 1), which extends over 600,000 km 2 and covers one-third of the Arabian subcontinent (Edgell, 2006;White et al, 2001), has an extensive cover of Quaternary deposits. These mostly comprise aeolian dune systems with a suite of alluvial fans along the margins of the Hajar Mountains, and localised palaeolakes and inland sabkhas (Farrant et al, 2012a).…”