塔里木盆地主要前陆冲断带差异构造变形

调查，对比分析三大前陆冲断带构造变形特征，进一步探讨控制前陆冲断带差异变形特征的主要因素。塔里木盆地周缘前陆盆地构造变形的差异性主要体现在剖面上的分层差异性和平面上的分带、分段差异性。库车前陆冲断带发育4套滑脱层，剖面上深、中、浅层构造样式差异明显；塔西南前陆冲断带发育3套滑脱层，构造分层特征较为明显；塔东南前陆冲断带发育2套滑脱层，构造的分层性与库车、塔西南前陆冲断带比较则相对简单。区域构造应力场、盆地边界等则控制了前陆冲断带变形样式的分段、分带差异。库车前陆冲断带与天山构造带走向一致，具有明显的构造分带性，在局部应力调节处表现出一定的构造分段性差异；塔西南前陆冲断带与昆仑山挤压方向呈不同角度相交，沿走向上体现出明显的构造分段性，在各段存在分带差异；塔东南前陆冲断带构造分段性明显，分别与西昆仑山和阿尔金山的主控作用有关，向盆地方向分带特征不太明显。

关键词： 前陆冲断带；滑脱层；构造变形；分层；分段；分带；控制机理；塔里木盆地

中图分类号： P54 文献标志码： A

Abstract： According to field investigation， based on typical profiles of Kuqa， southwestern Tarim and southeastern Tarim areas， the characteristics of structural deformation for the three foreland thrust belts were contrasted， and the main controlling factors of differential structural deformation were discussed. The differences of structural deformation of foreland basin around Tarim Basin are layered difference in vertical domain and segmentation and zonation differences in horizontal domain. Four detachment layers develop in Kuqa foreland thrust belt， and the differences of deep， middle and shallow tectonic styles in vertical domain are significant； three detachment layers develop in southwestern Tarim foreland thrust belt， and the layered characteristics of structure are significant； two detachment layers develop in southeastern Tarim foreland thrust belt， and contrasted with the above foreland thrust belts， the layered characteristics of structure is relatively simple. The regional tectonic stress field and basin boundary control the segmentation and zonation differences of deformation style of foreland tectonic belts. The strike of Kuqa foreland thrust belt， which is consistent with that of Tianshan tectonic belt， has obvious structural zonation； there is a certain segmentation in partial stress accommodation zones. Because of the different angles intersecting with the compression of Kunlun Mountains， the southwestern Tarim foreland thrust belt has obvious structural segmentation along the strike， and there is zonation in each segment. The southeastern Tarim foreland thrust belt is characterized by structural segmentation， which is mainly controlled by West Kunlun Mountains and Altun Tagh Mountains respectively； zonation towards the basin is not obvious.

Key words： foreland thrust belt； detachment layer； structural deformation； layered； segmentation； zonation； control mechanism； Tarim Basin

0 引 言

塔里木盆地与天山、西昆仑山、阿尔金山等构造带相邻，在盆地周缘山前相应分布有库车、塔西南和塔东南等前陆冲断带[1-4]。库车前陆冲断带已探明克拉2、依南、迪那2等油气田，是国家“西气东输”工程的主要气源地。

推荐访问:塔里木盆地 构造 变形 差异 前陆冲断带