Deformation processes related to early stages of collisional belts, especially the inversion of rifted systems remain poorly constrained, partly because evidence of these processes is usually obliterated during the subsequent collision. The Pyrenean belt resulting from the inversion of a Cretaceous hyperextended rifted margin associated with a high‐temperature and low‐pressure metamorphism in the Internal Metamorphic Zone (IMZ), is a good example for studying the early stage of orogenic deformation. This study is focused on the Eastern Pyrenees where the relation between inverted Mesozoic rifted basins and their basement are well‐preserved. By using maximum temperatures (T_max) estimated by the Raman Spectroscopy of Carbonaceous Materials geothermometer and structural data, we describe the spatial distribution of the various tectono‐metamorphic units. T_max recorded in the sedimentary cover exposed to the north and to the south of a Paleozoic basement block (Agly massif), exceed 550°C, while the Paleozoic metasediments and their autochthonous Mesozoic cover show T_max < 350°C. The metamorphic sedimentary cover is affected by ductile deformation, while the basement is only affected by brittle deformation. Post‐metamorphism breccias are observed between the basement and the metamorphic sedimentary cover, which are interpreted as a décollement level in the Upper Triassic evaporites. Unlike previous models suggesting that the basement block separated two metamorphic basins (Boucheville and Bas Agly) during rifting, we propose a large displacement of a single metamorphic basin by a large thrust above the basement block. This novel interpretation emphasizes the general allochthonous position of the former hyperextended rift basin (IMZ) thrusted along a decoupling layer.

中文翻译：

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超伸展盆地倒置过程中的地下室盖解耦：东比利牛斯山脉的见解

与碰撞带早期阶段有关的变形过程，特别是裂陷系统的倒转，仍然受约束较弱，部分原因是这些过程的证据通常在随后的碰撞过程中被消除。比利牛斯山脉带是由白垩纪超伸展裂谷边缘倒转引起的，而该边缘与内部变质带（IMZ）中的高温和低压变质有关，是研究造山变形早期的一个很好的例子。这项研究的重点是东比利牛斯山脉，中生代裂陷盆地与它们的基底之间的关系得到了很好的保留。通过使用最高温度（T _max）由碳素材料地热仪的拉曼光谱法和结构数据估算，我们描述了各种构造变质单元的空间分布。暴露于古生代基底块（Agly地块）北部和南部的沉积覆盖层中记录的T _max超过550°C，而古生代沉积及其中生代覆盖层显示T _max <350°C。变质沉积层受韧性变形的影响，而地下室仅受脆性变形的影响。在地下室和变质沉积盖层之间观察到了变质后角砾岩，这被解释为上三叠纪蒸发岩中的剥落水平。不同于先前的模型表明基底块体在裂谷过程中将两个变质盆地（Boucheville和Bas Agly）分开，我们提出了一个单个变质盆地在基底块体上方受到较大推力的大位移。这种新颖的解释强调了沿解耦层推进的前超伸展裂谷盆地（IMZ）的一般异形位置。