论文部分内容阅读
通过对西藏阿里札达盆地河湖相地层实测剖面中的古地磁、ESR样品的测试分析,确定了札达盆地新近纪上新世—第四纪早更新世沉积地层的时间序列。测试结果表明:从剖面自下而上所做的古地磁测年数据为5.41~1.60Ma;而ESR测年数据为5.4~1.36Ma,两者大体吻合。根据古地磁、ESR测年结果,可将该套河湖相地层的时序划分为:上新世托林组(N21t)的形成时间为5.41~4.20Ma、上新世古格组(N22g)为4.20~2.57Ma、早更新世香孜组(Qp1-1x)为2.57~1.36Ma。为青藏高原新近纪上新世—第四纪早更新世地层时间序列标尺的建立,以及上新世、早更新世河湖相地层的划分与对比提供了重要依据。
The time series of sedimentary strata of the Pliocene-Quaternary Pleistocene in the Zanda Basin were determined by testing and analyzing the paleomagnetic and ESR samples from the measured sections of the river-lacustrine facies in the Arid Zanda Basin, Tibet. The test results show that the dating data from the bottom to the top of the profile are 5.41 ~ 1.60Ma, while the ESR data are 5.4 ~ 1.36Ma, which are in good agreement with each other. According to paleomagnetic data and ESR dating results, the sequence of the lacustrine facies can be divided into the following sequence: the formation time of the Upper Neolitocene Formation (N21t) is 5.41 ~ 4.20Ma, that of the Pliocene Group (N22g) is 4.20 ~ 2.57Ma, Early Pleistocene aixin group (Qp1-1x) was 2.57 ~ 1.36Ma. It provides an important basis for the establishment of the sequence of the Pliocene-Quaternary Pleistocene stratigraphic time series ruler in the Qinghai-Xizang Plateau and the division and comparison of the Pliocene and Early Pleistocene fluvial-lacustrine facies strata.