山西吉县沃曲桃园下三叠统刘家沟组红层的古地磁研究  

PALEOMAGNETIC STUDY ON RED BEDS, LIUJIAOGOU FORMATION (TRL) FROM TAOYUAN, YAOQU, JIXIAN, SHANXI PROVINCE

作　　者：谈晓冬[1] 方大钧[1] 袁友仁[2] 范时清[2] 包继忠 

机构地区：[1]浙江大学地球科学系,杭州310027 [2]中国科学院南海海洋研究所,广州51030 [3]山西省地质矿产局213地质队,临汾031000

出　　处：《地球物理学报》1991年第6期736-743,共8页Chinese Journal of Geophysics

摘　　要：本文对鄂尔多斯盆地东南缘一个背斜剖面的早三叠世红层样品进行了古地磁研究.对逐步热退磁矢量序列进行主成分分析以及各磁组分的解阻温度谱分析,估计了携磁矿物.分离出4种磁成分:镜铁矿携带的沉积或沉积后剩磁;赤铁矿携带的化学剩磁;等温剩磁和粘滞剩磁.特征剩磁(最高解阻温度T_u≥670℃)通过倒转检验、(递增)褶皱检验,平均方向为偏角D=-25°,倾角I=41°,相应的极位置为65°N、356°E.We have investigated the characteristics of remanent magnetizations of lower Triassic red beds from an anticlinal section at the southeast edge of Ordos basin. The pilot specimens were subjected to step-wise thermal demagnetization up to 670℃. On the basis of multicomponent analysis with the standard package LINEFIND, we calculated the unblocking temperature spectrum of each magnetic compenent, and estimated the magnetic carriers. The study reveals that red beds in this section consist of four remanent components, i.e., the chemical, depositional or post-depositional, isothermal and viscous remanent magnetizations. The characteristic remanent magnetizations (ChRM) (the highest unblocking temperature Tu=670℃) pass the posifive reversal and (incremental) fold tests. Its sample mean direction, declination D=-25℃, inclination I= 41°, and the paleopole correspondingly is at 65°N 356°E.

关 键 词：古地磁 三叠世 刘家沟组 红层 山西 

分 类 号：P318.4[天文地球—固体地球物理学]