地质通报2013，Vol.32Issue(1)：111-119,9.
柴达木盆地大红沟剖面新生代地层岩石磁学特征与环境演变
The Cenozoic rock magnetic characteristics of the Dahonggou section in Qaidam Basin and the climate change
摘要
Abstract
This paper has discussed the climate change in northeastern Tibetan Plateau according to the Cenozoic rock magnetic characteristics of the Dahonggou section in Qaidam Basin. Progressive thermal demagnetization of typical samples indicates that the percentage composition of magnetite increases with the strata getting younger. The sediments in Qaidam Basin exhibit a noticeable increase in magnetic susceptibility by 5 stages, which is coincident with the increase in the percentage composition of magnetite. The change of magnetic susceptibility of sediments in Qaidam Basin was closely related to climate change: ①the increase in magnetic susceptibility at about 43Ma resulted from the climate cooling and drying; ② the increase in magnetic susceptibility at 33Ma or so resulted from the global climate cooling; ③the tectonic uplift of the Tibetan Plateau at about 22Ma resulted in the climate system that controlled China's continental environment change from the planetary system of winds to the monsoon of winds and also caused aridi-fication in Asian inland. Hence the magnetite was preserved and the magnetic susceptibility increased; ④the regional tectonic uplift in northeastern Tibetan Plateau at about 14Ma resulted in the expansion of the western arid region and the intensification of eastern Asian monsoon. Meanwhile, the global ice volume extended. Therefore, the magnetic susceptibility of the sediments in Qaidam Basin rose and the fluctuation range and frequency increased.关键词
柴达木盆地/大红沟/沉积物/磁化率/气候演变Key words
Qaidam Basin/ Dahonggou/ sediments/ magnetic susceptibility/ climate change分类
天文与地球科学引用本文复制引用
柯学,季军良,宋博文,王朝文,张楗钰,孙作本,张宗言..柴达木盆地大红沟剖面新生代地层岩石磁学特征与环境演变[J].地质通报,2013,32(1):111-119,9.基金项目
中国地质调查局国家青藏专项项目《青藏高原新近纪隆升过程与地质事件群研究》(编号:1212011121261)和国家自然科学创新研究群体基金项目《重大地质突变期生物与环境协同演化》(批准号:40921062) （编号:1212011121261）
