GE Benwei1,2, LIU Anna1
(1. Department of Geography, College of Science, Shihezi University, Shihezi 832000, China;
2. Xinjiang Laboratory of Lake Environment and Resources in Arid Zone, Wulumuqi 830000, China)
Abstract: In this paper, loess grain size and magnetic susceptibility from two loess sections at different altitudes in northern slope of the Tianshan Mountains, China were analyzed. Differences in grain size and magnetic susceptibility were discussed and paleoclimatic significance was also analyzed in this paper. Results indicate that grain size characteristics of Lujiaowan (LJW) section at the altitude of 2074 m are similar to that of Dafosi (DFS) section at the altitude of 527m. However, particle of loess from LJW section is finer than that from DFS section. Specifically, fine particle distribution range of LJW is wider than that of DFS, while coarse particle is the opposite. Magnetic susceptibility of Holocene palaeosoil layer in LJW section is positive correlated with pedogenesis, suggesting pedogenesis model. However, magnetic susceptibility from the last glacial loess layer in LJW and Holocene loess in DFS is positive correlated with coarse particles, suggesting wind model. In this area, topography and altitude between two sections are responsible for their difference in grain size and magnetic susceptibility. The reason is that high altitude brings about finer particle accumulation, more precipitation and stronger pedogenesis in northern slope of the Tianshan Mountains, especially comparing with lower elevations. Climate during the Holocene recorded in DFS is drought and stable. Contemporary climate recorded in LJW is relative humid due to the influence of topography.
Key words:loess; palaeosoil; magnetic susceptibility; environmentally sensitive component; northern slope of the Tianshan Mountains
EARTH AND ENVIRONMENT Vol.45, No.5, Tot No.319, 2017, Page 491-499