摘要
南天山冲断褶皱系是中—上新世以来形成的以薄皮滑脱为主的冲断构造 ,冲断作用导致了盆地内及周缘区古—新生界的碎屑岩和碳酸盐岩地层发主形变。本文对该冲断系前缘区 (巴音库鲁提北部至喀什地区 )的运动学特征进行了研究。南天山冲断褶皱系从平面上分出了六个冲断褶皱带。从剖面上划分出两种不同的冲断体系。冲断系的前锋为盲冲结构的构造三角带。冲断作用导致前锋区中新世以来层系变形、抬升并出露地表 ,本区有两个区域性的主滑脱面 ,冲断作用及断层相关褶皱的形成是冲断层沿主滑脱面向前陆方向逐渐推进的结果。同时发育的次级冲断层导致冲断褶皱带的复杂化。文章同时指出 ,南天山冲断褶皱系的冲断扩展顺序为逆序。这与塔里木盆地南缘西昆仑山前冲断带的活动方式相反 ,暗示着南天山构造带的运动学特征是独特的。利用平衡地质剖面的方法 ,在综合地质和地球物理资料的基础上 ,作出本区的构造横剖面图并进行了平衡恢复 ,从而得出南天山冲断褶皱系前缘区上新世以来的南北缩短率为30 % ,缩短量为 5 0km ,缩短速率为 9— 10mm/a。
The Southern Tianshan thrust-fold systems are thin skin thrust structural belts formed after Miocene and Pliocene. Thrusting resulted in Palaozoic-Cenozoic clastic and carbonate rocks deforming in basin and margins regions. The kinematics characters of thrust front regions (Northern Bainkuluti and Kashi) were discussedThe Southern Tianshan thrust-fold systems were divided into six structural belts on plane and two tectonic layers in section. The blind thrust structural deltas were formed in thrust belts front.Thrusting made for Miocene strata deformation, uplift and denudation. There were two detachment surfaces. Thrusting on detachment surfaces gradually spreaded toward foreland and formed fault-related folds. That embranchment faults formed during structure activity made thrust belts more complication.The author indicated that thrust propagating of the Southern Tianshan thrust-fold systems were inverted sequence. The results were different from sequence of thrust-fold belts in Western Kunlun Mountain. It implicated that the Southern Tianshan thrust-fold systems were provided with unique kinematics characters. Using method of the balanced section, the structural crossing section was made and restored on the based of geology and geophysical data. Sequentially these were got that shorting percentage of the Southern Tianshan thrust-fold systems was 30%、that shorting amount was 50km and that shorting velocity was 9-10mm/a.
出处
《沉积学报》
CAS
CSCD
北大核心
2000年第3期439-444,共6页
Acta Sedimentologica Sinica
关键词
南天山
冲断带
运动学特征
平衡剖面
褶皱系
southern Tianshan thrust-fold belts kinematics characters balanced section
