Imprint of the Reguibat Promontory (West Africa) on the Appalachian, Mauritanide and Souttoufide Belts, During the Assembly of Pangea

In the course of the Carboniferous to Permian assembly of Pangaea, large parts of eastern Laurussia and northern Gondwana were affected by the Variscan Orogeny. Here, we particularly focus on the Appalachian belt of eastern Laurentia and the Mauritanide of western Gondwana. Owing to the irregular shapes of the craton margins, the collision between the Laurentia and the West African Craton provides several conjugate promontories and embayments alongside both cratons. Among others, the coupled pair formed by the African Reguibat promontory and its counterpart in North America, the Pennsylvania embayment is the principal subject of this study. The western movement of the Reguibat Shield had initially imprinted the West African belts but finally also affected the Appalachians. Forming such a “punch mark” producing two specific lobes (stacks of nappes) on both sides of the promontory. The southern NW-SW lobe (e.g. Akjoujt nappes) is known since a long time. However, the northern lobe of the “Adrar Souttouf Massif” has not been identified previously owing to its partially covering and also by its N-S alignment instead of an expected symmetrical SW-NE direction. Furthermore, the Adrar Souttouf Massif is partially covered by allochthons terranes (WTB or Appalachians). This new discovery supports a classical impingement model for the deformation of the North American and African belts by westward moving of the Reguibat Shield.