青藏高原始新世构造岩相古地理

摘要

On the basis of the data obtained from 1:250000 geological mapping conducted by China Geological Survey during 1996-2008 as well as other data available concerning the Cenozoic strata, and through integrated researches on the tectonic setting and lithostratigraphic sequence of remnant basins in Eocene, the authors investigated the evolution of Eocene tectonic lithofacies paleo-geography in the Tibetan Plateau. In the Eocene period, uplift and erosional areas existed in Songpan-Garze and Gangdise, depressed basins (lakes and pluvial plain) lay in eastern Tarim, Qaidam, Qiangtang and Hoh Xil, and Neo-Tethys Sea was located in western and southern Tibetan Plateau. Based on researches on the tectonic—lithofacies paleogeographic evolution in Eocene and its response to the tectonic uplift of the Tibetan Plateau, the authors recognized two major uplift events, which happened during 55-51Ma and 45-34Ma respectively.%在前人研究成果的基础上,分析青藏高原始新世残留盆地的构造背景、岩石地层序列和青藏高原始新世期间的构造岩相古地理特征.松潘-甘孜和冈底斯带为大面积构造隆起蚀源区,塔里木东部、柴达木、羌塘、可可西里地区主体表现为大面积的构造压陷湖盆-冲泛平原沉积,高原西部和南部为新特提斯海.从构造岩相古地理演化的角度揭示青藏高原始新世构造隆升与沉积响应的耦合关系,划分出2个强隆升期,分别是强隆升期Ⅰ (55～51Ma)和强隆升期Ⅱ(45～34Ma).