Interpretation of the Eastern Sulaiman fold-and-thrust belt, Pakistan: A passive roof duplex
Interpretation of the Eastern Sulaiman fold-and-thrust belt, Pakistan: A passive roof duplex
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DOI：
10.1016/j.jsg.2019.06.010
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发表时间：
2019-09-01
影响因子：
3.1
通讯作者：
Idrees, Muhammad
中科院分区：
文献类型：
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作者：
Jadoon, Saif-Ur-Rehman K.;Ding, Lin;Idrees, Muhammad
综合苏莱曼东部褶皱冲断带(SFTB)的地表地质、地震反射和钻井资料，分析了SFTB的构造几何学、变形样式、前陆构造发育和构造缩短作用。北S向褶皱带的变形前锋在沿北S褶皱带东缘350多公里处具有类似的单斜特征。剖面上显示出约9公里厚的台地层序，在古生代地层中通过推测的滑脱作用从基底分离出来。白垩纪地层的底部在前深向斜中类似于6公里深，在没有大冲断的情况下在前陆类似于7公里隆起，被解释为薄皮被动顶板双重变形样式。侏罗系和老地层的双重层序与白垩纪和年轻的顶板层序分离，在前陆构造上方约60公里的范围内完好无损。该地区平衡的构造剖面恢复到172公里的原始长度，这意味着自6+/-2 Ma以来缩短了112公里(65%)，速度为18毫米/年。这大于沿着359公里长的N-S平衡横断面发生的类似于50%的缩短，但很可能发生在沿SFTB东部具有高起伏的堆叠复式结构上。
Surface geology, seismic reflection, and well data from the eastern Sulaiman fold-and-thrust belt (SFTB) were integrated to analyze its structural geometry, deformation style, foreland structure development, and tectonic shortening. The N-S oriented fold belt's deformation front has a monoclinal expression over similar to 350 km along the eastern edge of the SFTB. The cross-section shows a similar to 9 km thickness of platform sequences that are detached from the basement by an inferred decollement in Paleozoic strata. The base of Cretaceous strata is similar to 6 km deep in the foredeep syncline, rising similar to 7 km in the foreland in the absence of a major thrust, and is interpreted as a thin-skinned, passive-roof duplex style of deformation. The duplex sequence of Jurassic and older strata are separated from the Cretaceous and younger roof sequence, which is intact over foreland structures for similar to 60 km. A balanced structural cross-section of this area restores to an original length of 172 km, implying similar to 112 km (65%) of shortening since 6 +/- 2 Ma, with rates of 18 mm/yr. This is greater than the similar to 50% shortening along a 359 km long N-S balanced cross-section across the SFTB, but is likely to occur along stacked duplexes with high relief along the eastern SFTB.