The Koudiat El Madene unit (Kabylian “Dorsal”, Algeria) and its correlation with similar units belonging to the Rif-Betic Arc (Morocco and Spain)

Abstract

The Koudiat El Madene Unit (Arba Massif) belongs to the Kabylian “Dorsal” (Algerian Internal Zone). The stratigraphy and tectonic structuring of the area is equivalent to the western Moroccan Internal Rif and its counterpart in the Spanish Internal Betic Cordillera. In fact, all these chain segments are due to a common Cenozoic geodynamic evolution related to the closure of the westernmost Tethys and the later opening of the Mediterranean Sea. Nevertheless, a comparison of the Kabylian internal units at the western Mediterranean scale was still missing. This study means a revisiting of the outcrops of the Koudiat El Madene Unit and a revision of the existent literature on the area aimed to a comparation of this area with the Algerian Kabylian “Dorsal” and with the Ghomaride (Moroccan Rif) and Malaguide (Spanish Betic Cordillera) equivalents units. This unit crops out in a tectonic window under different backthrusting units of the Maghrebian Flysch Basin Zone and overthrusts southwards the Maghrebian Flysch Basin Zone itself and the External Tellian Zones. This is a frequent tectonic situation of this kind of units in the internal Rif-Betic chains. The condensed succession of the Koudiat El Madene Unit, separated by unconformities but also by internal erosive boundaries, is divided into five stratigraphic formations. Nowadays, the stratigraphic division and dating of the Koudiat El Madene Unit (Algerian Kabyle Unit) are less detailed than its equivalents in the Ghomarides, especially those of the Malaguides. Nevertheless, a correlation with the Ghomaride Units from the Tetouan-Chaouen area (Northern Morocco) and the Malaguide Complex from the Sierra Espuña area (Southeastern Spain) has been performed revealing great similarities. The good correlation can be due to a close paleogeographic position in the southern margin of the Paleo- and Mesomediterranean Microplate. Minor variations should be proposed in relation to the position in the margin. Detailed and modern stratigraphic and sedimentological studies are required to propose a more precise paleogeographic framework.