罗布泊盆地新构造变形数值模拟分析  

A NUMERICAL SIMULATING RESEARCH ON NEOTECTONICS IN THE LOP NUR BASIN

作　　者：施炜[1] 田蜜[1,2] 马寅生[1] 龚明权[1] 杜建军[1] 刘源[1] 

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]中国石化石油勘探开发研究院无锡石油地质研究所,无锡214151

出　　处：《地质力学学报》2011年第3期223-231,共9页Journal of Geomechanics

基　　金：中国石油塔里木油田公司科技项目(41005050002);国土资源大调查项目"新构造与重要经济区和重大工程安全系列图件编制"(1212010511507);"贺兰山-六盘山构造地貌带地表过程与演化机理"(1212011120100)资助

摘　　要：综合罗布泊盆地新构造研究相关成果,运用数值模拟实验方法,采用两种模型,对罗布泊盆地新构造活动进行数值模拟研究,直观展示盆地的应力状态与位移特征,再现罗布泊盆地新构造变形序列,查明运动学特征。数值模拟结果一方面展示出晚新生代以来罗布泊盆地先后主要经历了渐新世末期—早更新世晚期近南北向构造挤压作用控制下的盆地近东西向伸展断陷与早更新世晚期以来北东—南西向构造挤压作用导致的盆地剪切变形两大阶段;另一方面实验结果也显示,在两种边界条件的控制下,研究区地质单元的应力状态主要受地层岩性和断裂共同控制,盆地内部呈现低应力状态,在与最大主压应力相垂直的方向上产生伸展变形。盆地南边的两条主干断裂内部具有较高的剪应力,而罗布泊盆地及其以东地区剪应力最小。位移大小明显受断裂控制,从南西向北东位移逐渐减小,指示孔隙流体从南西向北东运移。Based on analysis of previous researches on neotectonic in Lop Nur Basin,two types of numerical simulation models have been built in this paper： ~N-S trending compression in first stage and NE-SW striking compression in the later stage.Combining with the previous studies,our numerical simulation shows the two main episodes of tectonic evolution occurred in the Lop Nur Basin since Late Cenozoic：（1） the ~N-S trending compression,the extension and rifting from late Oligocene to Early Pleistocene,and（2） the NE-SW striking compression and the shearing deformation since Early Pleistocene.Furthermore,the research shows the stress condition of the geological units is controlled both by lithology and faults;moreover,the low stress appears inside of the basin,and extensional direction is perpendicular to maximum principle compressive stress.The two main faults to the south of the basin are dominated by high shearing stress,whereas the minimal shearing stress distributes both in the basin and to its east.Furthermore,obviously controlled by faults,the displacement decreases from southwest to northeast,indicating the pore fluid migrates from southwest to northeast.This study provides some structural evidences for the research on sylvite forming and oil storage and transformation.

关 键 词：罗布泊盆地 新构造 数值模拟 阿尔金断裂带 塔里木盆地 

分 类 号：P546[天文地球—构造地质学]