A palaeomagnetic and mineral magnetic study of the loess sequence at Liujiapo, Xian, China
A palaeomagnetic and mineral magnetic study of the loess sequence at Liujiapo, Xian, China
复制标题
DOI：
10.1002/jqs.3390060104
复制
发表时间：
1991-03
影响因子：
2.3
通讯作者：
L. Thistlewood;Sun Jianzhong
中科院分区：
文献类型：
--
作者：
L. Thistlewood;Sun Jianzhong
为了进一步完善现有的磁地层记录，在西安附近刘家坡黄土剖面26 m处，采用平均垂直采样间隔20 cm的定向取样方法。古地磁结果显示，在一个以正常磁化为主的沉积物剖面中，存在两个短极性反转亚带，这一解释与本剖面和中国黄土的其他研究结果不同。沉积物的矿物磁性能研究表明，磁化强度、磁化率和饱和等温的下剖面变化与岩性有着密切的对应关系。IRM-100mT/SIRM和SIRM/敏感性比值似乎是土壤发育程度和古气候的特别敏感指标。
Employing an average vertical sampling interval of 20 cm, oriented samples were collected from 26 m of the loess section at Liujiapo, near Xian, China in order to refine the existing magnetostratigraphic record. Palaeomagnetic results reveal two short reversed-polarity subzones within a profile of predominantly normally magnetised sediments, an interpretation that is at variance with previous results from this section and from other studies of Chinese loess. Investigation of sediment mineral-magnetic properties indicates a close correspondence between down-section variations in intensity of magnetisation, susceptibility and saturation isothermal Journal of Quaternary Science remanence (SIRM), and lithology. The ratios IRM-100mT/SIRM and SIRM/ susceptibility appear to be particularly sensitive indicators of the degree of soil development and hence of palaeoclimate.