西藏班公湖地区侏罗纪-白垩纪沉积及古海洋盆地的演化

在西藏1∶25万喀纳幅、日土县幅地质调查图成果的基础上,重建了班公湖-怒江结合带西段3个地层区的侏罗纪-早白垩世沉积地层序列,对地层纵向、横向序列变化和沉积环境进行对比分析,指出在侏罗纪-早白垩世时,班公湖-怒江中特提斯洋盆沉积与其南、北两侧大陆边缘沉积有明显差异;中特提斯海洋盆地演化经历了早-中侏罗世深海-半深海沉积、晚侏罗世-早白垩世残余海(洋)盆地沉积和晚白垩世残余海盆消亡等3个阶段。

Jurassic Cretaceous sedimentation and evolution of ancient oceanic basin in Bangong Lake Area,Tibet.

Based on the geological survey of 1∶250 000 scale in Kana and Ritu Areas, we recognized the vertical and horizontal variation of sedimentation, studied the sedimentary environment and reestablished the Jurassic Cretaceous sedimentary sequence in three strata areas of western Bangong Lake Nujiang suture zone. It was specified that the sedimentation in Bangong Lake Nujiang middle Tethys oceanic basin was clearly different from both the southern and northern continental margin of the ocean in Jurassic Cretaceous period. The evolution of the middle Tethys Oceanic basin can therefore be divided into three stages as early middle Jurassic deep water ocean, later Jurassic to early Cretaceous relict basin with shallow water sedimentary rocks and later Cretaceous remnant oceanic basin withering away.