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Construction of a quartz osl standardised growth curve (SGC) for Aeolian samples from the horqin dunefield in northeastern China

100%

Yang L. , Lai Z. , Long H. , Zhang J.

tom Vol. 38, no. 4

391-396

It has been suggested that the standardised growth curve (SGC) method can be used to determinate De accurately and reduce the measurement time. However, different opinions regarding the applicability of the SGC method exist. In this paper, we report the construction of quartz OSL SGC for 35 aeolian samples from different parts of the Horqin dunefield in northeastern China, and then test their applicability for De determination. Our results suggest that: 1) up to a regeneration dose of 80 Gy, the SGC of the Horqin dunefield can be fitted using the exponential plus linear equation, with the r2 value of 0.97, and all the regeneration dose points closely stick to the fitting line, implying that all samples share a very similar dose-response curve; 2) for samples with De s ranging from 1 to 50 Gy, the ratios of SAR De to SGC De fall within the range of 0.9-1.1, and the average ratio of SAR De to SGC De is 1.01š0.01, close to unity. Therefore, the construction of SGC is correct, and the SGC is an effective procedure for accurate De determination for samples from the study area.

Late Glacial and Holocene vegetation and climate history of an alpine wetland on the Qinghai-Tibetan Plateau

75%

Liu D. L. , Chen G. , Lai Z. , Weis H. , Zhou G. , Peng M.

tom Vol. 57, No. 2

261-–268

This study provides a vegetation and climate history of an alpine wetland in the centre of China’s Qinghai–Tibetan Plateau (QTP) over the last 14.8 ka. High resolution climate proxies include vegetation (pollen), geochemical (Ba, Rb, δ13C) and physical (particle size and magnetic susceptibility) data; optically stimulated luminescence (OSL) and AMS radiocarbon dating were used to reconstruct the environmental changes in the wetland ecosystem. Based on physical and geochemical proxies, the sucession divided into five stratigraphic units encompassing time intervals of 14.76–14.31, 14.31–13.17, 13.17–4.47, 4.47–0.51 and 0.51–0 ka. The average sedimentation rate of all these units was 0.098 mm/a. The study showed that this ecosystem was sensitive to climate change.