Mineral magnetic study of the Taklimakan desert sands and its relevance to the Chinese loess

Abstract

SUMMARY We conducted a mineral magnetic study on sand samples from the Taklimakan desert, Tarim Basin in western China. Modern sands were collected at 19 sites in the central and western parts of the Taklimakan desert. We carried out low-field susceptibility measurements, ARM and IRM acquisitions, high- and low-temperature measurements and hysteresis measurements on these samples. Nearly stoichiometric magnetite is the dominant magnetic mineral of these samples. The presence of titanomagnetite is unlikely, and contributions from a high-coercivity mineral(s) are minor. Magnetic grain size is estimated to be that of larger pseudo-single domain or even greater. We compared the hysteresis data against loess samples from both pristine and weathered loess sections from the Chinese Loess Plateau. We found an apparent decreasing grain size trend from the Taklimakan to the central Loess Plateau through the western Loess Plateau. These lines of evidence favour the idea that the Taklimakan desert is one of the potential dust source areas, even though it is located more than 2000 km west of the central Loess Plateau.