The deformed Paleozoic succession of the Eastern Moroccan Meseta crops out in relatively small and isolated inliers surrounded by Mesozoic and Cenozoic rocks. Two of the largest inliers (Mekkam and Debdou) are characterized by a monotonous succession of slates and greywackes affected by polyphasic folding that occurred at low‐ to very low grade metamorphic conditions. New U‐Pb ages on detrital zircon grains from the Debdou‐Mekkam metasediments constrain the maximal depositional age as Late Devonian, interpreted to be close to the true sedimentation age. Furthermore, the ε_Hf values of the Devonian detrital zircons, together with the presence of a series of scattered zircon grains with ages between c. 0.9 and c. 1.9 Ga, suggest provenance from a subduction‐related magmatic arc located on the Avalonian margin. The Debdou‐Mekkam massif is characterized by an Early Carboniferous first deformational event (D1), which gave way to a pervasive cleavage (S1) associated with plurikilometric‐scale, tight to isoclinal, overturned to recumbent folds. Later events (Dc) occurred at Late Carboniferous time and generated variably developed crenulation cleavages (Sc) associated with variously oriented metric‐ to kilometric‐scale folds, which complicate the pattern of both D1 intersection lineations (L1) and axial traces. The restoration of this pronounced curved pattern yields originally SW‐NE‐oriented D1 fold axes with regional SE‐vergence. This important Early Carboniferous shortening and SE‐directed tectonic transport can be explained by closure of the Rheic Ocean and the first phases of the collision between the northern passive margin of Gondwana and an Avalonian promontory.

中文翻译：

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东部摩洛哥中层的构造演化：从泥盆纪前缘沉积到阿瓦隆海角的早期石炭纪碰撞

东部摩洛哥Meseta的变形古生代演替系在相对较小且孤立的中生地带中，周围是中生代和新生代岩石。最大的两个内线（Mekkam和Debdou）的特征是在低至非常低品位的变质条件下，受到多相折叠影响的板岩和灰w的单调连续。Debdou-Mekkam沉积物中碎屑锆石的新U-Pb年龄限制了最大沉积年龄为泥盆纪晚期，被解释为接近真实沉积年龄。此外，_εHf泥盆纪碎屑锆石的总值，以及一系列年龄在c之间的分散锆石颗粒的存在。0.9和c。1.9 Ga，建议来自阿瓦隆边缘俯冲相关岩浆弧的物源。Debdou-Mekkam断层以早期石炭纪第一变形事件（D1）为特征，该事件被普遍的裂隙（S1）所取代，与多斜度尺度相关，紧紧到等斜，倒伏到斜re。后来的事件（Dc）发生在石炭纪晚期，并产生了可变发展的齿状裂痕（Sc），与各种方向的公制到千公尺的褶皱有关，这使D1交汇点线（L1）和轴向迹线的图案复杂化。恢复这种明显的弯曲图案后，将产生具有局部SE收敛的原始SW‐NE导向的D1折叠轴。这种重要的早期石炭纪缩短和东南向构造运动可以用莱茵河的封闭以及冈瓦纳北部被动边缘与阿瓦隆海角之间碰撞的第一阶段来解释。