西藏羌塘盆地中生代构造岩相演化及油气远景  

MESOZOIC TECTONIC-PETROGRAPHIC EVOLUTION AND OIL-GAS PERSPECTIVE IN QIANGTANG BASIN,TIBET

作　　者：杨日红[1] 李才[1] 杨德明[1] 和钟铧[1] 任云生 刘焱木 

机构地区：[1]长春科技大学地球科学学院,吉林长春130026

出　　处：《长春科技大学学报》2000年第3期237-242,共6页Journal of Changchun University of Science and Technology

基　　金：中国石油天然气总公司青藏油气勘探项目经理部项目!(QZ - 95 - 2 0 412 7)

摘　　要：西藏羌塘盆地中生代构造岩相组合分带及特征明显 ,可以反映羌塘盆地的演化史。早中三叠世北羌塘构造岩相组合表现为前陆盆地沉积 ,而南羌塘盆地为剥蚀环境 ;至晚三叠世除中央隆起剥蚀外 ,北羌塘仍为前陆盆地沉积 ,而此时南羌塘坳陷演化成陆缘海沉积。早侏罗世早期盆地开始坳陷 ,造成相对较窄沉积相的构造岩相组合特点 ,初步形成“两坳一隆”的构造格局 ;中侏罗世南北羌塘坳陷继续下降 ,“两坳一隆”的构造格局更加明显 ;晚侏罗世羌塘盆地发育到晚期 ,并萎缩、封闭成型。从构造岩相组合特征看 ,中侏罗统北羌塘坳陷龙尾湖—雀莫错凹陷区与南羌塘坳陷蒂让碧错凹陷区都是有利于储、聚油气的远景区。The evolution history of Qiangtang basin is recorded by the tectonic-petrographic assemblage zones. There was a foreland-basin sedimentation in north Qiangtang at T 1 and T 2 period, but an erosion environment in south Qiangtang at the same time. In T 3, the centre upwarp belt was an erosion area, the north Qiangtang was still foreland-basin sedimentation, meanwhile, south Qiangtong had been already evolved to be a marginal sea sedimentation. In fact, the primary basin began to sag in J 1 and formed a narrow sedimentary belt. Owing to the continnous downwarping during J 2 period, the tectonic pattern of “two-sag and one-upwarp” of the basin was established. Qiangtang basin was wilted, cutoff and moulded in the end of Jurassic as the latest stage of basin development. The tectonic-petrographic assemblage evidences show that the medial Jurassic Longweihu-Quemocuo sag of north Qiangtang belt and Dirangbicuo sag of south Qiangtang belt are the favorable oil-gas prospective targets.

关 键 词：西藏 羌塘盆地 构造岩组合 油气远景 中生代 

分 类 号：P534.5[天文地球—古生物学与地层学] P618.130.2[天文地球—地质学]