塔里木盆地寒武系台缘结构特征及其演化

Structural characteristics and its evolution of Cambrian platform margin in Tarim Basin

乔博 高志前 樊太亮 罗静 孟祥杰

中国地质大学（北京）能源学院，北京 100083 中国地质大学（北京）海相储层演化与油气富集机理教育部重点实验室，北京 100083

School of Energy Resources, China University of Geosciences, Beijing 100083, China MOE Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Enrichment Mechanism, China University of Geosciences, Beijing 100083, China

塔里木盆地寒武系因具重大的油气资源潜力而成为目前油气勘探的目标，其台缘斜坡带以发育优质礁滩体储层并控制台地内部沉积相带发育而备受关注。综合分析地震、露头、钻/测井资料，明确了寒武系各层组发育时期台缘斜坡带的特征及其控制的台地沉积环境。研究发现，早寒武—中寒武世早期各层组均发育缓坡型台缘斜坡带，中寒武世晚期—晚寒武世发育镶边型台缘斜坡带。受海平面升降变化和碳酸盐岩产率的控制，不同地区各层组台缘斜坡带叠加样式不同：塔西南地区为缓坡的退积—加积型，塔中地区为缓坡—镶边的进积—加积型，塔北地区为镶边的进积型。台缘斜坡带整体呈一向柯坪地区收敛的“U”形，塔北—塔中地区台缘带逐渐向东部盆地方向迁移，塔西南地区则向北台地内部迁移。台地边缘类型及其迁移不仅控制了台缘礁、滩的发育，也控制了台内沉积相的构成及展布规律。

Cambrian is becoming the exploration target in Tarim Basin due to its great potential of oil and gas resources, especially its platform margin which develops high-quality reservoir and controls the sedimentary facies in the platform. Through comprehensive analysis of seismic, outcrop, core and logging data, the characteristics of the platform margin and the sedimentary facies under its control are clear. Based on these data, it is proved that ramp platform margin develops in the early Early-Middle Cambrian, rimmed shelf platform margin develops in the late Middle Cambrian-Late Cambrian. The stack patterns of platform margin are different in different regions: the progradated-aggradated ramp platform margin develops in southwestern Tarim Basin; the progardated-aggradated ramp-rimmed shelf platform margin develops in central Tarim Basin; the progradated rimmed shelf platform margin develops in northern Tarim Basin. The platform margin convergences towards Keping like as a U-shaped stripe in the west of the Tarim Basin. In Cambrian, the platform margin migrates towards to the east in northern and central Tarim Basin, while in the southern Tarim Basin, the platform margin migrates towards to north. The patterns of platform margin and its migration not only control the development of reefs and beaches, but control the sedimentary facies and their distributions.

10.6056/dkyqt201401002