塔里木盆地西北缘石炭-二叠系浊积岩的沉积特征及其构造意义

目的研究塔里木盆地西北缘晚石炭世晚期—中二叠世早期(逍遥—栖霞期)浊积岩沉积特征及其构造意义。方法对塔里木盆地西北缘上石炭统上部—中二叠统下部的浊积岩进行岩石、岩相和时空变化特点的分析。结果从晚石炭世晚期—早二叠世早期到中二叠世早期,浊积岩的沉积范围显著减小,沉积区域在向西南方向收缩的同时水体则进一步加深。结论这种沉积-构造特点反映当时南天山造山带内部处于强烈的构造活动状态,南天山造山带向塔里木地块的冲断推覆可以导致这种沉积-构造格局;从沉积学的角度提出南天山造山带在晚石炭世晚期—中二叠世早期可能处于碰撞造山作用的晚期阶段。

The sedimentary feature and structure significance of turbidite Carboniferous Permian on the northwestern margin of the Tarim Basin

Aim To evaluate the sedimentary feature and structure significance of turbidite of top of Upper Carboniferous-bottom of Middle Permian on the northwestern.Methods Make analysis of turbidite lithologic,facies and the feature of time-space variation of late period of Late Carboniferous-early period of Middle Permian.Results It indicates that from late period of Late Carboniferous-early period of Early Permian to early period of Middle Permian,the sedimentary area of turbidite was decreased remarkably,and it removed to southwest,at the same time,the water got deeper.Conclusion The feature of sedimentary-structure shows that the structure activity in interior of south Tianshan Mountain belt is intensely,and the sedimentary-structure framework of turbidite is owing to the overthrust of south Tianshan Mountain to the Tarim block.This study reflects that the south Tianshan Mountain belt of Late Carboniferous-early period of Middle Permian is in late period of collision orogens.