PAN lang=EN-US>According to the characteristics of the grain-size distribution of the sand-dune, the medium grain-size (40～90 μm) quartz was applied to measure Equivalent dose (De) using the Simplified SAR protocol. The De determinations obtained from both the SAR protocol and the Simplified SAR for five samples are good agreement within a standard deviation. The nineteen samples collected from the Wendi profile have been dated by the Simplified SAR for the medium grain (40～90 μm) quartz.The results suggested that the loess-like sand-dune could be at least developed in about 55 ka ago and continued to the early Holocene, and that dune accumulation rate could be evidently changed in about 32 ka ago in Yellow River valley between Shannxi and Henan provinces on the basis of OSL dating results.
