干旱区湖泊沉积物磁组构参数量值特征环境变化研究

对干旱区终闾湖泊沉积物磁组构参数进行了研究，表明干旱区湖泊沉积物磁组构参数值基本介于水动力，风动力沉积物的量值之间。在湖相，湖沼相，泥炭层及受人类影响的洪泛沉积段，沉积物磁组构参数值有明显的区别，同时在同一沉积相中其参烤值也存在较大的变化，指示了沉积动力强度和沉积环境方面的差异。

STUDY ON MAGNETIC FABRIC PARAMETERS OF LAKE SEDIMENTS IN ARID AREA AND ENVIRONMENTAL CHANGES

Two 2.7m long sections from the centers of two nearly dry lakes,Yema and Qingtu Lakes in the Shiyang River drainage in Minqin basin of the arid NW China,were used to study the magnetic anisotropy of lake sediments and environmental changes.The results show that the value of magnetic anisotropy of the lake sediment is between those of fluvial and eolian sediments;the magnetic anisotropy varies greatly in lake facies,marsh facies,peat layers and floodwater sediments due to human activity.Our results also indicate that fluctuation of magnetic anisotropy coincides with that of magnetic susceptibility,grain size,chemical composition proxies of the lake facies.This result leads to the conclusion that magnetic anisotropy of the lake sediment reflects changes in sedimentary power and environment,and hence can be used as a climate proxy.