中生代焉耆盆地演化特征

The evolution characteristic of Yanqi Basin in the Mesozoic

目的探讨焉耆盆地中生代盆地的演化。方法通过盆地断裂活动特征、沉积演化特征探讨盆地演化阶段。结果盆地断裂活动分为3个阶段,中晚三叠世挤压断层发育阶段、侏罗纪—早白垩世伸展正断层发育阶段和晚白垩世挤压逆冲断层发育阶段;沉积演化分为两个阶段,中—晚三叠世挤压环境的辫状河—浅湖相沉积,早—中侏罗世伸展环境的辫状河—浅湖相沉积。结论焉耆盆地中生代的演化可分为中晚三叠世前陆盆地阶段、侏罗纪—早白垩世的伸展阶段和晚白垩世的挤压抬升阶段3个阶段。

Ahn To discuss the Yanqi Basin evolution phases in the Mesozoic. Methods Disscuss the basin evolvement phases according to the characteristic of the basin stratum, fault activity and depositional evolution. Resuits The basin fracture activity had the three activity phases： the phase of extruded fault in Middle-Late Trias, extensional positive fault in Jurassic-Early Cretaceous and thrust fault in Late Cretaceous. Yanqi Basin depisitional phase included river-shallow-lake facies under extrusion in Middle-Late Trias and river-shallow-lake facies under extensional surroundings in Early-Middle Jurassic. Conclusion Three phases were partitioned on the Mesozoic Yanqi Basin evolvement： foreland basin phase in Middle-Late Trias, extensional phase in Jurassic-Early Cretaceous and extruded-raised phase in Late Cretaceous.