柴达木盆地盐湖沉积磁性地层年代学研究进展

Research progresses on magnetostratigraphy of saline lake deposit in Qaidam Basin

柴达木盆地因其巨厚的新生代盐湖沉积成为研究青藏高原隆升、古湖泊演化、气候环境演变以及盐类资源钾盐勘探开发的热点地区之一。而磁性地层年代学是这种长尺度湖相沉积研究中必不可少的定年方法。总结了早期柴达木盆地各个沉积中心的磁性地层结果,详细描述了近年来已发表的最新3个千米钻孔的磁性地层年代成果,包括柴达木盆地西部大浪滩沉积中心的梁ZK02孔和梁ZK05孔、察汗斯图拉沉积中心的SG-1孔。根据新的磁性地层年代结果,重新厘定了柴达木盆地西部沉积中心的第四纪底界深度,并为探讨柴达木盆地第四纪气候变化、青藏高原阶段性隆升和新型的砂砾层卤水资源提供了精确的年代制约。

Because of its thick Cenozoic saline lake sediments, the Qaidam Basin has become a hotspot of studies of the uplift of the Tibet Plateau, the paleolake evolution, the climate change and the salt resource exploration. The magnetostratigraphy is an essential dating method for such long scale lacustrine sediments. This paper reviews the early magnetostratigraphic results in the deposit centers of the Qaidam Basin, and the new three magnetostratigraphic results of kilometer-scale drill holes in detail, including the cores ZK02 and ZK05 in the Dalangtan playa, the core SG-1 in the Chahansilatu playa. Based on the new magnetostratigraphic results, the Quaternary boundary is redefined in the deposit center of the western Qaidam Basin, which provides accurate age constraints of the Quaternary climate change in the Qaidam Basin, the stepwise uplift of the Tibet Plateau, and the new brine in the sandy gravel.