^(36)Cl断代法应用于青藏高原末次快速隆升的构造事件研究  

Application of ^(36)Cl-Dating to the Last Rapid Uplift of the Tibet Plateau

作　　者：任收麦[1] 葛肖虹[2] 杨振宇[1] 林源贤[3] 胡勇[4] 刘永江[2] Johann GENSER Andrea B.RIESER 

机构地区：[1]中国地质科学院地质力学研究所 [2]吉林大学地球科学学院,长春130061 [3]天津地质矿产研究所,300170 [4]青海油田分公司勘探开发研究院,敦煌736202 [5]Department of Geography and Geology, University of Salzburg, Austria

出　　处：《地质学报》2006年第8期1110-1117,T0001,共9页Acta Geologica Sinica

基　　金：国家自然科学基金项目(编号40272099;40572135);科技部重大基础研究前期研究专项(编号2002CCA05100);博士点基金项目(编号20040183055)联合资助成果。

摘　　要：青藏高原的形成与隆升是多期次的,尤其早更新世晚期的快速隆升对全球气候变化、我国西部盆-山地貌形成与荒漠化的出现有着重大影响,这已成为近年地学研究的热点问题。通过对高原东北缘-柴达木盆地西部地区角度不整合面上下地层中红色泥岩36Cl断代法定年,首次测定该事件发生在早更新世晚期至中更新世(1.54～0.28MaB.P.)之间。结合敦煌盆地同时代地层(0.837MaB.P.和1.142MaB.P)的低角度掀斜现象,以及前人在塔里木盆地、柴达木盆地、吐鲁番—哈密盆地、酒西盆地的研究结果,认为早更新世晚期,受青藏高原快速隆升北向挤压作用的影响,我国西北地区发生了一次重要的构造事件,造成大范围的挤压变形与山脉隆升,这对我国西北地区构造格架的最终形成和晚期油气运移成藏具有重要意义。The forming and uplifting of the Tibet Plateau are multi-stage, and, the last rapid uplift of the plateau plays especially an important role in global climate change, basin-mountain tectonic formation in western China and appearance of desertification. It becomes a key scientific question recently. Based on field works, we recognized a high-angular unconformity well developed on the southern side of the Altun Mountain in the western Qaidam Basin. Pleistocene strata with slight dip outcrop on the northern side of the Altun Mountain in the southern Dunhuang Basin. Two groups of 36^Cl dating samples were collected from mudstone lens of fluvial sediments in the upper and lower unconformity plane in Goukougou in the western Qaidam Basin, and slightly incline mudstone layer in the southern Dunhuang Basin. The samples yield ages of 1. 535 Ma in the downside layer and 0. 277 Ma in the upside layer of the unconformity in Goukougou, and 1. 142 Ma and 0. 837 Ma in the southern Duanhuang Basin. In accordance with previous research related to this tectonic event in the Tarim Basin, Turpan-Hami Basin, Western Jiuquan Basin and Qaidam Basin, we argue that an important geological event happened in northwestern China after the Early Pleistocene, which responds evidently to the last rapid compression and uplifting of the northern Tibetan Plateau. Therefore, it is significant to understand the formation of tectonic framework and the late period oil-gas reservoirs in northwestern China.

关 键 词：柴达木盆地 早更新世 ^36Cl断代法定年 构造事件 

分 类 号：P542.1[天文地球—构造地质学]