|WANG Yong,YANG Xiangdong,SHEN Ji,PAN Hongxi,XIAO Xiayun.A 0.1 ka-year Record of Environmental Evolution in Hongjiannao Lake, Shaanxi Province. J. Lake Sci.2004,16(2):106-113. DOI:10.18307/2004.0202
|关键词: 红碱淖 湖泊沉积 环境演变
|A 0.1 ka-year Record of Environmental Evolution in Hongjiannao Lake, Shaanxi Province
WANG Yong1,2, YANG Xiangdong1, SHEN Ji1, PAN Hongxi1, XIAO Xiayun1
1.Nanjing Institute of Geography and Limnology, Chinese of Sciences, Nanjng 210008, P. R. China;2.Graduate School, Chinese Academy of Sciences, Beijing 100039, P. R. China
|The environment evolution in the past nearly 100 years was revealed by the multi-proxy analysis of lithology, grain size, magnetic susceptibility, TOC and geochemical elements from the Core H in Hongjiannao Lake, Shaanxi Province.The result indicates that Hongjiannao Lake was formed at about 1927 AD, characterised by a relatively higher value of Fe/Mn ratio and a lower level of lake productivity and magnetic susceptibility value.During the span between 1952 and 1960, the lake level rose remarkably, as shown by the sharp decrease of clay fraction and the obvious dilution effect on the geochemical elements concentration in sediment.The lithologic character and sediment proxies reflect that the lake has developed into a stable deep-water condition since 1960.The lake formation and its subsequent rapid expansion in the late 1950s related closely to the regional rainfall increases, and the latter also benefited from extensive reclamation of the lowland around the lake.Human activities have also resulted in the higher lake production and the changing of redox condition on sediment-water interface in the recent 40 years.Moreover, the 3 strong dust storm events happened in the late 1930s and 1940s were well distinguished in terms of the features of grain size frequency distributions in the sediment core.
|Key words: Hongjiannao Lake lake sediment environmental evolution