The Alpine Rif Belt (Morocco): A Case of Mountain Building in a Subduction-Subduction-Transform Fault Triple Junction
The Alpine Rif Belt (Morocco): A Case of Mountain Building in a Subduction-Subduction-Transform Fault Triple Junction
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DOI：
10.1007/978-3-0348-7899-9_3
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发表时间：
2004-03
影响因子：
2
通讯作者：
A. Chalouan;A. Michard
中科院分区：
文献类型：
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作者：
A. Chalouan;A. Michard
- Rif带与Betic Cordilleras在阿尔卑斯造山带的西端形成了围绕阿尔沃兰海的不对称弧形山带（直布罗陀弧）。直布罗陀弧由一个外来的阿尔沃兰地体（Alboran Terrane）组成，它冲过非洲和伊比利亚边缘。阿尔沃兰地体本身包括源自东部阿尔沃兰-卡比利亚斯-佩洛里塔尼-卡拉布里亚（阿尔卡佩卡）大陆域的堆叠推覆体，并显示华力西低级和高级片岩（分别为Ghomarides-Malaguides和Sebtides-Alpujarrides）、浅水中生代沉积物（主要在Dorsale Calcaire被动边缘单元）和陆下橄榄岩切片（隆达的贝尼布塞拉）。在白垩纪晚期？始新世，阿尔沃兰地体可能位于东南倾斜的阿尔卑斯-贝蒂俯冲带以南（参见。贝蒂斯中东部的Nevado-Filabride HP-LT变质作用。始新世晚期-渐新世期间，对伊比利亚的早期碰撞触发了变形的古陆南部的逆冲构造，并开始了西北倾斜的亚平宁-马格里布俯冲。早期，HP-LT阶段的Sebtide-Alpujarride变质作用可以假设为阿尔卑斯-Betic俯冲，或替代亚平宁-马格里布俯冲，这取决于地质年代学数据集的解释。两个俯冲带在中新世早期合并在阿尔沃兰地体西部，并与亚速尔群岛-直布罗陀转换断层形成一个三重连接。一个向西回滚的N向俯冲段是负责新近纪裂谷的内部Alboran地体，并为同时代，斜对接到非洲和伊比利亚边缘。活跃的E-倾斜俯冲的地震证据，以及直布罗陀弧的里夫和贝蒂奇分支的相反的古地磁旋转支持这种基于结构的情景。
—The Rif belt forms with the Betic Cordilleras an asymmetric arcuate mountain belt (Gibraltar Arc) around the Alboran Sea, at the western tip of the Alpine orogen. The Gibraltar Arc consists of an exotic terrane (Alboran Terrane) thrust over the African and Iberian margins. The Alboran Terrane itself includes stacked nappes which originate from an easterly, Alboran-Kabylias-Peloritani-Calabria (Alkapeca) continental domain, and displays Variscan low-grade and high-grade schists (Ghomarides-Malaguides and Sebtides-Alpujarrides, respectively), shallow water Mesozoic sediments (mainly in the Dorsale Calcaire passive margin units), and infracontinental peridotite slices (Beni Bousera, Ronda). During the Late Cretaceous?-Eocene, the Alboran Terrane was likely located south of a SE-dipping Alpine-Betic subduction (cf. Nevado-Filabride HP-LT metamorphism of central-eastern Betics). An incipient collision against Iberia triggered back-thrust tectonics south of the deformed terrane during the Late Eocene-Oligocene, and the onset of the NW-dipping Apenninic-Maghrebian subduction. The early, HP-LT phase of the Sebtide-Alpujarride metamorphism could be hypothetically referred to the Alpine-Betic subduction, or alternatively to the Apenninic-Maghrebian subduction, depending on the interpretation of the geochronologic data set. Both subduction zones merged during the Early Miocene west of the Alboran Terrane and formed a triple junction with the Azores-Gibraltar transform fault. A westward roll back of the N-trending subduction segment was responsible for the Neogene rifting of the internal Alboran Terrane, and for its coeval, oblique docking onto the African and Iberian margins. Seismic evidence of active E-dipping subduction, and opposite paleomagnetic rotations in the Rif and Betic limbs of the Gibraltar Arc support this structurally-based scenario.