当前位置: X-MOL 学术Tectonics › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Tectonic Evolution of the Northern Oman Mountains, Part of the Strait of Hormuz Syntaxis: New Structural and Paleothermal Analyses and U‐Pb Dating of Synkinematic Calcite
Tectonics ( IF 3.3 ) Pub Date : 2020-04-04 , DOI: 10.1029/2019tc005936
E. Carminati 1 , L. Aldega 1 , L. Smeraglia 1 , A. Scharf 2 , F. Mattern 2 , R. Albert 3, 4 , A. Gerdes 3, 4
Affiliation  

The Oman Mountains expose Permo‐Mesozoic shelf rocks of Arabia overridden by continental slope/basinal sediments and Semail Ophiolites during Late Cretaceous. A major syntaxis is represented by the Musandam Peninsula and Dibba Zone. The overthrusting of allochthonous units onto the Musandam shelf carbonates initiated during the Cenomanian. Structural analyses in the Musandam Peninsula constrained top‐to‐the‐west thrusting that took place 74–60 Ma ago (U‐Pb datings of synkinematic calcites), about 15–30 Ma after the obduction of the Semail Ophiolite. The Dibba faults exhibit a first interval of thrusting (top‐to‐the‐west) followed by dextral slip. We propose that SW vergent thrusts, initially parallel to those of the Central and Southern Oman Mountains, were subsequently rotated to their present‐day NE‐SW strike during the development of the syntaxis and then reactivated by dextral slip. Mixed layers illite‐smectite (I‐S) constrain the thermal evolution of the passive margin sequence and of the allochthonous deep‐water sediments. In particular, the proximal Hawasina unit (Hamrat Duru) and Sumeini groups of the Dibba Zone are characterized by long‐range ordered mixed layers I‐S with an illite content of 90–95%, whereas Musandam carbonate units show mixed layers I‐S with illite layers ranging from 80–90%, indicating deep diagenetic conditions. Such levels of thermal maturity were acquired during the Late Cretaceous emplacement of a 3.5‐km‐thick pile of allochthonous units, which were removed by erosion and denudation since the Campanian. U‐Pb dating of synkinematic calcite vein highlights reactivation of thrusts at 13.2 Ma, likely due to the involvement of the Musandam area in the Arabia‐Eurasia collision.

中文翻译:

阿曼句法海峡一部分的阿曼北部山区的构造演化:新的结构和古热分析以及方解石的U-Pb定年

在白垩纪晚期,阿曼山脉暴露了被大陆坡/基性沉积物和Semail蛇绿岩覆盖的阿拉伯亚的二叠纪-中生代架子岩。Musandam半岛和Dibba区是主要语法。切诺曼期开始将异源单元推覆到Musandam陆架碳酸盐上。Musandam半岛的结构分析限制了从74到60 Ma以前(从动向方解石的U-Pb年代开始)发生的顶推力,这是在Semail蛇绿岩引诱后大约15-30 Ma发生的。Dibba断层表现出第一个反冲间隔(从上到西),随后是右旋滑移。我们建议西南偏冲推力最初与阿曼中部和南部山脉的推力平行,随后在语法开发过程中被旋转到今天的NE-SW打击,然后通过右旋滑移重新激活。混合层伊利石-蒙脱石(IS)限制了被动边缘层序和异源深水沉积物的热演化。特别是Dibba区的近端Hawasina单元(Hamrat Duru)和Sumeini组的特征是伊利石含量为90-95%的远距离有序混合层I-S,而Musandam碳酸盐岩单元则显示混合层I-S伊利石层范围为80-90%,表明成岩条件很深。这样的热成熟度水平是在白垩纪晚期将3.5 km厚的异源单元堆积时获得的,自Campanian以来已通过侵蚀和剥蚀将其去除。
更新日期:2020-04-04
down
wechat
bug