塔里木盆地塔北地区T₇⁴不整合面古构造演变过程

Paleostucture evolution process of T74 unconformity in Tabei area, Tarim Basin

何松林 张小兵

中国科学院青藏高原研究所大陆碰撞与高原隆升重点实验室，北京 100101 中国科学院青藏高原研究所，北京 100101 中国科学院大学地球与行星科学学院，北京 100049 油气藏地质及开发工程国家重点实验室，四川 成都 610059

Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu 610059, China

塔里木盆地经历多次构造运动后，抬升剥蚀严重。剖析盆内地层的抬升剥蚀程度，重建盆内地层的古构造演变过程，对研究盆地隆坳格局迁移、油气分布聚集关系、油气成藏的控制条件具有重要意义。文中在厘定塔北地区T74不整合面的基础上，采用完善后的趋势厚度法和“同层多期”的思路，计算了塔北地区中下奥陶统顶面（T74不整合面）在各个主要构造期的剥蚀量；在恢复剥蚀量的基础上，利用标志层￣厚度分析法，恢复了T74不整合面在各个主要构造期的古构造；通过分析T74不整合面古构造演变史，探讨了T74不整合面的地形格局迁移，明确了T74不整合面演变过程与油气运聚成藏关系。

Tarim Basin, as the largest sedimentary basin in China, experienced serious uplift and erosion after many tectonic movements. Analyzing the erosion of the sedimentary strata in the basin and restoring the paleostructure of the corresponding strata before experiencing each major tectonic period are of great significance for studying the migration of the basin, the distribution and accumulation of oil and gas, and the controlling conditions of hydrocarbon accumulation. Based on the determination of the unconformity surface of T74 in Tabei area, the paper uses the improved trend thickness method and the idea of "multi-period in the same layer" to calculate the erosion of middle-lower Ordovician(T74 unconformity surface) in Tabei area during the major tectonic period. On the basis of the restoration of denudation, the paleostructure of T74 unconformities in all major tectonic periods were restored by using the marker bed thickness analysis method. The T74 unconformity surface was discussed by analyzing the evolution history of T74 unconformity surface paleostructure. The migration of the topographical pattern clarifies the purpose of the evolution of the T74 unconformity surface and the hydrocarbon migration and accumulation.

10.6056/dkyqt201904001