Optical dating of Holocene sand dune activities in the Horqin sand-fields in inner Mongolia, China, using the SAR protocol

The Horqin sand-field in northeastern Inner Mongolia, China, had been the fertile grassland in North China, but desertification and sand-dust storm have increasingly occurred in the past decades [Zhu and Wang, 1992. Theory and practice of sandy desertification in China (in Chinese with English abstract). Quaternary Sciences 2, 97]. To understand the Holocene sand dune activities in this region, five sand dune profiles were investigated, and 32 coarse grain quartz samples were dated by OSL using the single-aliquot regenerative-dose (SAR) protocol [Murray and Wintle, 2000. Luminescence dating of quartz using an improved single-aliquot regenerative-dose protocol. Radiation Measurements 32, 57–73]. For cross-checking, six organic-rich samples from the paleosols and sandy peat/mud were dated by both 14C and quartz OSL. With one exception, 14C and quartz OSL dating results show good agreements. Based on the consistent results of five sand dune profiles, a chronology of Holocene dune activity in Horqin sand-field is established as follows: (i) active sand dunes built up widely before 10 ka; (ii) dunes semi-stabilized between 10 and 7.5 ka ago; (iii) the dunes solidify and chernozem soils developed between 7.5 and 2.0 ka ago; and (iv) partially re-mobilization of dunes occurred since about 2.0 ka ago.