柴达木盆地中新世中期以来构造的运动学模型  

A kinematic model for the deformation of the Qaidam Basin since the Middle Miocene based on seismic data

作　　者：王胜利[1] 李维锋[2] 魏东涛[1] 谭彦虎[3] 卢华复[1] 

机构地区：[1]南京大学地球科学系,南京210093 [2]长江大学地球科学学院,荆州434023 [3]中石油青海油田公司,敦煌736202

出　　处：《南京大学学报（自然科学版）》2008年第1期25-41,共17页Journal of Nanjing University（Natural Science）

基　　金：国家自然科学基金(40576025);中国科学院边缘海地质重点实验室(MSGLO605)

摘　　要：柴达木盆地是位于青藏高原内部的山间盆地,盆地新生代的变形受到两侧山体隆升的主导.通过贯穿盆地地震剖面的精细构造解释和分析,依据生长地层的结构,我们认为自中新世中期以来昆仑山前冲断楔体以平均4.7 mm/a的速度向盆地逆冲,导致盆地南斜坡向昆仑山方向仰冲;这为东昆仑山北麓出露的倾向北向南逆冲的多条断层和盆地南部向南逆冲的断层控制的断层相关褶皱作用所证实.盆地北部祁连山前冲断楔体向盆地方向逆冲,导致盆地北部向北逆冲的断层在地表形成北翼陡、南翼缓的断层相关褶皱背斜,向北逆冲的断层在盆地东部局部位置出露地表.昆仑山前冲断楔体和祁连山前冲断楔体的楔顶已经相向冲断至盆地中部,并造成第四系的变形.The Qaidam Basin is one of the intermountain basins in western China,and its deformation was controlled by uplift of the bilateral mountains since the Middle Miocene.Based on interpretation and analysis of one seismic profile across the Qaidam Basin,we conclude that the southern slop of the Qaidam basin is thrust over the northern piedmont of the Eastern Kunlun Mountains with an average velocity of 4.7 mm/y since the middle Miocene,which is confirmed by several faults throwing southward and fault-related folding throwing southward in the southern part of the basin.The thrust wedge in the southern piedmont of the Qilian Mountains is thrust northward,and the branches of the roof back-thrust result in fault-related anticlines with gentle southern limbs and deep northern limbs and are cropped locally in the east segment of the northern flank of the basin.The wedge tops of the two thrust wedges in the southern piedmont of the Qilian Mountains and in the north piedmont of the Eastern Kunlun Mountains thrust over the middle part of the basin and have led to deformation of the Quaternary sediments.

关 键 词：柴达木盆地 中新世 昆仑山前冲断楔体 祁连山前冲断楔体 

分 类 号：P542[天文地球—构造地质学]