Tectonostratigraphic and structural imprints from balanced sections across the north-western Zagros fold-thrust belt, Kurdistan region, NE Iraq
Tectonostratigraphic and structural imprints from balanced sections across the north-western Zagros fold-thrust belt, Kurdistan region, NE Iraq
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伊拉克东北部库尔德斯坦地区扎格罗斯褶皱逆冲带西北部平衡剖面的构造地层和结构印记
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发表时间：
2015
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通讯作者：
S. Sulaiman
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作者：
A. A. Omar;F. Lawa;S. Sulaiman
在库尔德斯坦地区（伊拉克东北部）扎格罗斯褶皱冲断带西北段发现的巨型油气田成为世界各地石油公司和学者的研究目标。这项工作涉及构造地层学和跨几个构造域的截面平衡，以及测量和分析从早侏罗世到晚上新世超层序的地层格架。构造复杂性经历了不同的构造带，从叠瓦构造带开始，然后是高褶皱冲断带，最后在低褶皱冲断带的边界结束。因此，根据新批准的地质图和暴露层序地层柱、油井资料以及为数不多的有价值的地震剖面，构建了三个主要剖面。第三系和白垩纪的总缩短幅度分别为4.55 ~ 6%和15.3 ~ 20.7%，侏罗系的总缩短幅度分别为12.9 ~ 20.8%。Bazian-Sagrma-Qaradagh背斜、Pira Magroon背斜、Surdash背斜和Azmar背斜的部分缩短率分别为9.8% ~ 12.5%、47.3% ~ 73.2%、29% ~ 41.3%和20.9% ~ 60.5%。B-B剖面上的科米坦组（M. Turonian - Santonian）可作为该区缩短的最佳措施，缩短率为20.7%。Bazian-Sagrma-Qaradagh背斜部分缩短率为9.8% ~ 12.5%；皮拉马格鲁恩背斜从47.3.8%增加到73.2%，苏达什背斜从29%增加到41.3%，阿兹马背斜从20.9%增加到60.5%。总的缩短值较低，主要是受伸展构造期厚皮构造向渐新世和中新世薄皮构造转变的影响，以及其滑脱性质的变化，而所研究剖面的部分缩短值与伊朗Zagros段的缩短值基本一致。
The giant oil and gas fields discovered in the north-western segment of the Zagros fold-thrust belt in the Kurdistan region (NE Iraq) became targets for oil companies and academics around the world. This work deals with tectonostratigraphic and cross-sectional balancing across several structural domains and a stratigraphic framework that measures and analyzes supersequences from the Early Jurassic to the Late Pliocene in age. The structural complexity passes through different tectonic zones, starting from an imbricated zone, then a high folded thrust zone and terminating at the boundary with a low folded thrust zone. Accordingly, three major cross sections have been constructed based on a new ratified geological map and a stratigraphic column of exposed sequences, oil wells data which are integrated with the few available valuable seismic profiles. The total shortening measured in the tertiary rocks ranges between 4.55 and 6 % and 15.3 and 20.7 % in the Cretaceous sequence, while in the Jurassic interval, it is between around 12.9 and 20.8 %. The measured partial shortening percentages of the Bazian–Sagrma–Qaradagh, Pira Magroon, Surdash and Azmar anticlines range from 9.8 to 12.5 %, 47.3 to 73.2 %, 29 to 41.3 % and 20.9 to 60.5 %, respectively. The Kometan Formation (M. Turonian to Santonian) in the B–B cross section can be adopted as the best measure for shortening in this area, and this is equal to 20.7 %. The partial shortening percentages obtained from the Bazian–Sagrma–Qaradagh anticlines range from 9.8 to 12.5 %; these increase in the Pira Magroon anticline, from 47.3.8 to 73.2 %, and for the Surdash anticline, they are from 29 to 41.3 % and the Azmar anticlinorium from 20.9 to 60.5 %. The total shortening values are, in general, low and attributed to the influence of thick-skinned tectonics during extensional tectonic phases that changed to thin-skinned tectonics during Oligocene and Miocene times, as well as being due to variations in their decollement nature, while the partial shortening values of the cross sections studied mostly coincide with those in the Iranian Zagros segment.