Abstract The metamorphic core of the Betic-Rif orogenic chain (Alboran Domain) is made up of lower crustal rocks forming the envelope of the Ronda (Spain) and Beni Bousera (Morocco) peridotites. The deepest sections of the crustal envelopes are made of migmatitic granulites associated with diffuse acidic magmatic products, making these exposure and ideal site to investigate the textural and petrological connection between crustal anatexis and granite magmatism in the contintental crust. However, still debated is the timing of intracrustal emplacement of the peridotite bodies, with models proposing either Alpine (early Miocene) or Hercynian ages, and still uncertain is the linkage between peridotite emplacement and crustal anatexis. In this study, by combining rock textures with whole-rock geochemistry, metamorphic thermobarometry, the U-Pb zircon geochronology and the analysis of the garnet and zircon REE chemistry, we document the P-T-t evolution of the granulite facies migmatites that form the immediate envelope of the Beni Bousera peridotites of the Rif belt. A main episode of Permo-Carboniferous (ca. 300–290 Ma) deep crustal anatexis, melt extraction and migration is documented that we link to the crustal emplacement of the Beni Bousera peridotites during collapse of the Hercynian orogen. Correlation at a regional scale suggests that the Beni-Bousera section can be tentatively correlated with the pre-Alpine (Permo-Carboniferous) basement units tectonically interleaved within the orogenic structure of the Alpine chain. The results of this study provide ultimate constraints to reconstruct the tectono-metamorphic evolution of the Alboran Domain in the Western Mediterranean and impose re-assessment of the modes and rates through which Alpine orogenic construction and collapse occurred and operated in the region.

中文翻译：

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Beni Bousera 橄榄岩（Alboran 域，摩洛哥）包层中的海西期精矿：对地中海地区深部地壳根部构造变质演化的影响

摘要 Betic-Rif 造山链（Alboran Domain）的变质核由下地壳岩石组成，形成了 Ronda（西班牙）和 Beni Bousera（摩洛哥）橄榄岩的包层。地壳包层的最深部分由与弥漫性酸性岩浆产物相关的混合麻粒岩组成，使这些暴露成为研究地壳深熔与大陆地壳花岗岩岩浆作用之间的结构和岩石学联系的理想地点。然而，仍然有争议的是橄榄岩体在地壳内侵位的时间，模型提出了高山（早中新世）或海西纪，橄榄岩侵位与地壳贫矿之间的联系仍然不确定。在这项研究中，通过将岩石质地与全岩地球化学、变质热压测量相结合，通过 U-Pb 锆石年代学以及石榴石和锆石 REE 化学分析，我们记录了麻粒岩相混合岩的 PTt 演化，这些混合岩形成了 Rif 带的 Beni Bousera 橄榄岩的直接包层。Permo-Carboniferous (ca. 300–290 Ma)深地壳退缩、熔体提取和迁移的主要事件被记录在案，我们与海西造山带坍塌期间贝尼布塞拉橄榄岩的地壳就位有关。区域尺度的相关性表明，Beni-Bousera 剖面可以与在高山链造山结构内构造交错的前高山（二叠纪-石炭纪）基底单元暂时相关。