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

Spatial variations in sand sea geochemistry relate to mixing of different s ediment sources and to variations in weathering. Due to problems of accessi bility, adequate spatial coverage cannot be achieved using field surveys al one. However, maps of geochemical composition produced from remotely sensed data can be calibrated against limited field data and the results extrapol ated over large, inaccessible areas. This technique is applied to part of t he Rub' Al Khali in the northern United Arab Emirates. Trend surface analys is of the results suggests that the sand sea at this location can be modell ed as an east-west mixing zone of two spectral components: terrestrial redd ened quartz sands and marine carbonate sands. Optical dating of these sedim ents suggests that dune emplacement occurred rapidly around 10 ka BP, when sea level was rising rapidly. The spatial distribution of mineralogical com ponents suggests that this phase of dune emplacement resulted from coastal dune sands being driven inland during marine transgression, thereby becomin g mixed with rubified terrestrial sands. Copyright (C) 2001 John Wiley & So ns, Ltd.