摘要:
通过对研究区387个可靠退磁数据的分析,确定其原生剩磁的极性及其变化。在此基础上根据古地磁测试资料,引入小波分析方法,对塔里木盆地拜城古近纪红层进行了磁性地层精确划分,确定了不同层段的地质时代,建立了克拉苏河剖面磁性地层柱。样品测试结果表明,绝大部分样品的磁性较强,退磁曲线质量较高,且分离出两个稳定分量:低温分量和高温分量,由此进行主分量分析并利用菲舍尔统计法求得最终结果,在小波分析方法的帮助下,参照国际标准磁性地层年表和综合地层划分方案,建立克拉苏河磁性地层柱。确定出吉迪克组/苏维依组,苏维依组/库姆格列木组以及库姆格列木组底界年代分别为27.7M a、38M a、60.5M a。其沉积速率在10~130mm/m a。
Abstract:
Magnetostratigraphic data are presented from the Kelasu River section of Baicheng County in the northern part of Tarim Basin. A dual-polarity component of magnetization carried by magnetite delineates a magnetic stratigraphy of the mainly-reversed polarity. Magnetozones are dated by means of sporopollen biostratigraphy and integrated stratigraphy. According to the analysis of 387 samples, wavelet analysis is adopted to build the magnetostratigraphy in combination with the magnetic polarity time scale (MPTS). There are two primary series of strata in this section, and they are Kumugeliemu and Suweiyi. It is estimated that the times of their intervals are 27.7Ma, 38Ma, and 60.5Ma with the comparison to the magnetostratigraphy already established. The sedimentation rate is 10-130mm/ma.