Sedimentary aspects of the Eo-Alpine cycle on the northeast edge of the Arabian Platform (Oman Mountains)
Sedimentary aspects of the Eo-Alpine cycle on the northeast edge of the Arabian Platform (Oman Mountains)
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DOI：
10.1144/gsl.sp.1992.049.01.05
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
D. Rabu;J. Le Métour;F. Béchennec;M. Beurrier;M. Villey;C. Bourdillon-Jeudy de Grissac
中科院分区：
文献类型：
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作者：
D. Rabu;J. Le Métour;F. Béchennec;M. Beurrier;M. Villey;C. Bourdillon-Jeudy de Grissac
阿曼山脉阿拉伯地台的东北边缘由Jabal Akhdar和Saih Hatat两个窗口的原生单元代表，位于Hawasina和Samail推覆体的下方和前面。古-阿尔卑斯造山旋回开始于晚二叠世，在冈瓦纳边缘伸展，结束于坎帕尼亚期，形成了一个俯冲-逆冲型山脉，即晚白垩世阿曼山脉。在这一旋回期间，长期稳定的陆架沉积被张性构造事件打断，通常伴随着火山活动和台地沉降，进入深海域。二叠纪至坎帕纪的沉积发生在五个主要的沉积旋回中。在晚二叠世（穆尔加比亚），一个广泛的海侵覆盖了冈瓦纳边缘的张拉环境。“Fusulinid海”海侵之后是沉积，一直持续到三叠纪，一个厚的退退层序，Akhdar群，在大陆环境中出现和风化而终止。下一个沉积旋回以Sahtan群为代表，开始于Pliensbachian时期，阿曼山区形成内碳酸盐岩陆架，结束于Tithonian早期。梯东世晚期，整个台地边缘受到拉张、盘状断裂和沉入深海域的深刻影响，Kahmah群（maiolica型沉积：含钙岩泥晶）沉积，大陆斜坡迅速后退约250公里。更新的碳酸盐陆架沉积随后向南西向北北东推进，穿过了被击毁的部分，尽管在最新的阿普提亚-阿尔比亚海侵发生时，这一过程仍不完整。在Cenomanian-Turonian边界，陆架经历了深刻的重组，陆架内发育了穆提盆地，形成了Aruma群，Masqat-Musandam高地为穆提盆地提供了碎屑，填满了大陆一侧的穆提盆地和海洋一侧的Hawasina盆地。从坎帕尼亚期开始，推进推覆体的碎屑体才在穆提盆地重新沉积，并在此期间在穆提盆地的部分地区叠加了复理石槽。穆提盆地的闭合受到推覆体在台地上的侵位以及随后在推覆体和原土上的盖层沉积的影响。
Abstract The northeast edge of the Arabian Platform in the Oman Mountains is represented by the autochthonous unit that crops out in the two windows of Jabal Akhdar and Saih Hatat, beneath and in front of the Hawasina and Samail nappes. The Eo-Alpine orogenic cycle began in the Late Permian with extension on the margin of Gondwana and ended in the Campanian with the formation of a subduction-obduction-type mountain range, the Oman Mountains of the Late Cretaceous. During this cycle, long periods of stable shelf sedimentation were interrupted by tensional tectonic episodes, often accompanied by volcanism and subsidence of the platform, passing into the bathyal domain. Deposition during the Permian to Campanian occurred during five main sedimentary cycles. In the Late Permian (Murghabian), a widespread marine transgression covered the edge of Gondwana in a tensional setting. The ‘Fusulinid Sea’ transgression was followed by the deposition, lasting until the Triassic, of a thick regressive sequence, the Akhdar Group, which was terminated by emergence and weathering in a continental environment. The next sedimentary cycle, represented by the Sahtan Group, began in the Pliensbachian, when the Oman Mountains area formed an inner carbonate shelf, and ended in the early Tithonian. The entire margin of the platform was profoundly affected, in the late Tithonian, by extension, listric faulting and foundering into the bathyal domain, with deposition of the Kahmah Group (Maiolica-type deposits: calpionellid-bearing micrite), and rapid retreat of the continental slope by about 250 km. Renewed carbonate shelf deposition then prograded SSW-NNE across the foundered part, though this was still incomplete when the latest Aptian-Albian transgression took place. At the Cenomanian-Turonian boundary, the shelf underwent profound reorganization with the development of the Muti (intrashelf) Basin, in which the Aruma Group was deposited, and the Masqat-Musandam High which provided the detritus filling the Muti Basin on the continentward side and the Hawasina Basin on the oceanic side. Fragments from the advancing nappe were redeposited in the Muti Basin only from the Campanian on, and it was only during this period that a flysch trough became superimposed on part of the Muti Basin. The closure of the Muti Basin was affected with the emplacement of the nappes on the platform and the subsequent deposition of cover formations over both nappes and the autochthon from the late Maastrichtian onward.