Paleogeographical reconstruction of the Malaguide-Ghomaride Complex (Internal Betic-Rifian Zone) based on Carboniferous granitoid pebble provenance

Abstract

An outcrop of Carboniferous conglomerates is described in the Malaguide-Ghomaride Complex in Ceuta, comparable to the Conglomerate Formation of Marbella. Granite cobbles and pebbles belonging to deformed peraluminous granites from epizonal massifs are significantly present within the conglomerates studied. Granites with these characteristics abound in the Central Iberian and Western Asturian-Leonese Zones and differ from those predominating in the Ossa-Morena and South Portuguese Zones of the Iberian Massif, geographically nearest the current Malaguide outcrop. This suggests that the Malaguide-Ghomaride Domain was originally situated towards the east, thus forming the prolongation of the Central Iberian or Western Asturian-Leonese Zones. This paleogeographical hypothesis is also confirmed by stratigraphic comparisons indicating close similarities between the Devonian and Carboniferous series of the Malaguide and of the more distant Minorca or Catalonian Coastal Range, as well as clear differences with the successions of the South Portuguese and Ossa-Morena Zones. Furthermore, the correspondence of the Malaguide-Ghomaride Domain towards the south with the Moroccan Meseta is also discussed. The nature of the granite cobbles of the Malaguide is a new argument that supports the contention of its westward shift of hundreds of kilometers during the Early Miocene, then forming the Gibraltar Arc and occupying its present-day position.