摘要
柯坪冲断带位于塔里木盆地西北缘,是新生代南天山褶皱冲断系的一部分。本文根据野外实际考察和地震剖面解释,总结了该冲断带的构造变形特征。它是发育于古生界中且以中寒武统膏盐层为主滑脱面的薄皮构造,是内部结构相对简单的叠瓦状冲断,因更新世才定型而具暴露式冲断前锋,有断层传播褶皱发育但已遭强烈剥蚀,前展式冲断。上新世晚期的冲断曾控制了磨拉石盆地发育(西域组砾岩),但该盆地已遭更新世的冲断推覆作用破坏。根据平衡剖面恢复,柯坪冲断带南部3排冲断层的总构造缩短量为29.1%~40.7%。
The Kalpin thrust belt or Kalpin fold-and-thrust belt, located in the northwestern margin of the Tarim Basin, is a part of the South Tianshan fold-and-thrust system. On the basis of field investigation and seismic section interpretation, the main features of the Kalpin thrust belt could be summerized as the follows. 1 )Only the Paleozoic rocks were involved into the thrusting, which meant that the major detachment fault was gypsum-salt layer in the Middle Cambrian. 2)The belt was characterized by imbricated thrusting, with a relatively simple inner texture. 3)The belt had an exposed thrust front, since it did not create till Pleistocene. 4)The fault-propagation folds once occurred, which were experienced violently denuded. 5)The belt was a piggyback one, with the thrusting expanded southwards. 6) A molasse basin once occurred during Pliocene, with the geological records being conglomerate of the Xiyu Formation, but the basin had been disrupted by the Pleistocene thrusting-nappe structuring. The Kalpin thrust belt consisted of the northern fold sub-belt and the southern thrust-nappe structural subbelt, and for the latter, the balanced section analysis revealved the minimal shortening rate being 29.1% to 40.7%.
出处
《地质科学》
CAS
CSCD
北大核心
2009年第1期50-62,共13页
Chinese Journal of Geology(Scientia Geologica Sinica)
基金
国家重点基础研究973项目(编号:2006CB202301)和中国科学院知识创新工程重要方向项目(编号:KCX3-SW-147)共同资助.
关键词
柯坪冲断带
南天山褶皱冲断系
变形特征
更新世
塔里木西北缘
The Kalpin thrust belt, The South Tianshan fold-and-thrust system, Deformational features, Pleistocene, NW margin of the Tarim Basin
作者简介
王国林,男,1964年7月生,高级工程师,博士后,石油地质学专业。e-mail:wguolin@cnpe-nile.com