摘要
对塔里木盆地库车—塔中—塔南剖面进行磁异常反演 ,提取异常体的剩磁倾角 ,结合古地磁、构造热事件和岩石磁性等资料 ,研究盆地基底的演化。结果表明 ,南、北塔里木地块经历了不同的热演化史 :北塔里木基底主要受早期古生代构造热事件的影响 ,中央隆起和南塔里木基底主要受二叠纪构造热事件的影响。在南、北和中区内都有沿深部断裂发育的剩磁倾角较陡的磁异常体 ,与火山岩对应。二叠纪之后 ,地壳相对稳定 ,盆地基底的演化基本结束。
Based on the magnetic anomaly inversion of Kuche-Tazhong-Tanan profile, we obtained the residual magnetic inclination of each anomaly body Combining with the information of paleomagnetism, structural heat events and the magnetic properties of rock, the basement evolution of the Tarim basin is also studied. The results suggest that, seperated by the Tazhong high magnetic belt, northern and southern Tarim basements have different magnetic property and underwent different heat evolution process The magnetic property of northern Tarim basement is very weak Its residual magnetic inclination is about 12°and the paleo latitude is 6° The basement of northern Tarim is influenced obviously by the Early Palaeozoic heat event, which was caused by the development of Kuman aulacogen in the north basin However, the magnetic property of southern Tarim basement, including the central Uplift and southern area of Tarim basin, is strong Its residual magnetic inclination is about 52°and the paleo latitude is 32° The basement of southern Tarim is influnced mainly by the Permian heat event, related to the B type subduction in the southern basin and the sloping A type subduction in the northerr basin during the Permian Magnetic bodies also developed along deep faults in the solid basement with subvertical residual magnetic inclination and correspond to volcanic rocks This confirms the existance of deep faults in the Tazhong and to the south of Ander After the Permian, the crust is relatively stable and the basement evolution almost ended in the Tarim basin Generally, the Tabei Uplift and Beibu Depression are reliable source areas because there are abundant oil source rocks which have not been influenced seriously by heat events after Early Palaeozoic But in the Southern Tarim, the oil accumulation of the Early Palaeozoic perhaps has been destroyed by several heat events and strong volcanic action, although it is a potential area for prospecting oil of the Late Palaeozoic to Cenozoic [WT5HZ]
出处
《高校地质学报》
CAS
CSCD
2000年第1期34-39,共6页
Geological Journal of China Universities
基金
国家 96 - 111攻关项目的部分研究成果
国家自然科学基金重点资助项目!(批准号 :49832 0 0 4)
关键词
磁异常
基底演化
古地磁
塔里木盆地
油气勘探
magnetic anomaly inversion
basement evolution
paleomagnetism
structural heat event
Tarim basin
