Palaeogeography, facies and nomenclature of the Triassic units in the different domains of the Betic Cordillera (S Spain).

Abstract

This paper reviews and discusses the different facies and nomenclature of the Triassic in the Betic Cordillera (S Spain). Emphasis is placed on problems encountered when studying Betic basin facies and palaeogeographic domains. In Triassic times, the Betic basin was positioned between the Iberian and Mesomediterranean Plates. We therefore propose the designations Southiberian Triassic and Mesomediterranean Triassic for the Triassic rocks that crop out in the External and Internal zones respectively of the Cordillera. Although facies types vary substantially, several similarities in their main stratigraphic features link the two palaeogeographic domains. Thus, Buntsandstein, Muschelkalk and Keuper facies can be currently distinguished in both domains of the External and the Internal Zones of the Betic Cordillera. Most rocks were coastal and shallow-marine sediments deposited across an extensive and varied palaeogeography, which defines the Sephardic domain. For some epochs, this last domain shows the influence of Alpine fauna and even palaeogeographically gives rise to subdomains characteristic of Alpine facies that today crop out in some Internal Zone units. This variety of facies makes the study of the Triassic in the Betic Cordillera all the more interesting.