柴达木盆地中新生代构造演化及其与油气成藏关系  

Meso-Cenozoic Tectonic Evolution of Qaidam Basin and Its Relationship with Oil and Gas Accumulation

作　　者：赵凡[1,2] 孙德强[3] 闫存凤[1,2] 张小军[1,2] 孙松领[1] 倪祥龙[1] 程玉红[1] 

机构地区：[1]中国石油勘探开发研究院西北分院,甘肃兰州730020 [2]中国石油天然气集团公司油藏描述重点实验室,甘肃兰州730020 [3]中国科学院科技政策与管理科学研究所能源与环境政策研究中心,北京100190

出　　处：《天然气地球科学》2013年第5期940-947,共8页Natural Gas Geoscience

基　　金：中国石油重大专项"柴达木盆地建设千万吨油气田综合配套技术研究"(编号:2011E-0302)资助

摘　　要：柴达木盆地是中国西北地区一个中、新生代陆相含油气盆地,具有青藏高原区域构造背景,位处两大汇聚板块的过渡地带,并与周缘造山带相伴生;发育于被动板块边缘之上,自中生代以来,其分别经历2次由弱到强的拉张和挤压作用,最终形成了一系列复杂构造样式。就形成机制而言,柴达木盆地是柴达木微板块向北俯冲碰撞及相应的南祁连山不断隆升和向南逆冲—推覆北昆仑山不断隆升共同作用的结果。通过野外区域地质调查、地震地层学以及钻井资料研究和分析,揭示出柴达木盆地自中生代以来,盆地演化经历了4个不同的盆地演化阶段,即早—中侏罗世断陷沉积盆地阶段、晚侏罗世—早白垩世伸展盆地反转和相应挠曲型盆地形成阶段、晚白垩世—始新世盆地整体缓慢平稳沉降阶段、自渐新世以来印度—欧亚大陆强烈碰撞引起的盆地挤压和抬升阶段,特别是在第4个演化阶段使柴达木地块处于明显的挤压和抬升状态,并逐渐形成盆地的现今地质结构。最后分析了盆地构造演化与油气成藏的关系,指出柴达木盆地油气勘探前景广阔。Qaidam Basin was one of the continental petroliferous basins of Meso-Cenozoic in northwest Chi- na,and it had the same regional tectonic setting with Tibetan Plateau. Qaidam Basin,which was formed in specific structural boundary conditions,was located in the transitional zone of two huge convergence plates accompanying with peripheral orogenic zone,and developed in the passive plate boundary, which mean it was formed in the plate convergence enviffonment. Qaidam Basin respectively underwent two stages of com- pression from weak to strong in Meso-Cenozoic, which formed a series of structural patterns related to fold- thrust action. Therefore the formation of Qaidam Basin was the result of two actions,one was the subduc- tion-collision of Qaidam microplate to the north accompanying with south Qilian Mountains uplifting and the other was its thrusting-napping to the south accompanying with north Kunlun Mountains rising contin- uously. Through geological survey,seismic stratigraphy and analysis on oil-well drilling data,this paper il- lustrates a four-period evolution of Qaidam Basin since the Mesozoic Era. During the Early-Middle Jurassic epoch,the basin was under influence of block differences,the crust was stretched and a faulting-subsiding basin came into being. From the Late Jurassic Epoch to the Early Cretaceous Epoch,because of the closure of oceanic lithosphere and the collision of neighboring blocks, Qaidam Basin was under a compressive tec- tonic regime, which led to a turn-over of the early basin and the formation of a warping basin. At the age of Late Cretaceous Epoch Eocene Epoch,the new Tethys tectonic evolution led to the stretching of middle A- sia and the vast northwestern of China, and the whole Qaidam Basin settled down slowly. Since Oligocene Era, the powerful collision of Indian and Eurasian blocks compressed Qaidam Basin and made it as an extru- sion and uplift stage. Especially during the 4th stages of evolution,the Qaidam blocks at a distinct state ex- trusion and uplift, which ultimately form

关 键 词：盆地演化 中新生代 油气聚集 柴达木盆地 

分 类 号：TE122.1[石油与天然气工程—油气勘探]