Las unidades de la Zona Bética en la región de Aguilas-Mazarrón (prov. de Murcia)

Abstract

Three geographic domains are defined in the region: Northern, Central and Southern, separated by vertical fractures trending originally ENE-WSW. Different sets of tectonic units outcrop in each of them. In the Northern Domain over the materials of the Mulhacén Nappe, three alpujárrides units have been distinguished; they are composed of a metapelitic sequence and a carbonate formation which are judged to be Pennotriassic and Triassic, respectively, in age. The relative autochthon of the units appearing in the Central Domain is constituted by a tick serie of black schists and quartzites defined here as a new unit of the Veleta Group which has been named "The Lomo de Bas Unit". This unit is overridden by an alpujárride unit of similar characteristics to the alpujárrides units appearing in the Northern Domain and another unit belonging to the Maláguide Complex. At the contact between these latter and the Lomo de Bas three are remnants of a sedimentary formation similar to the Conglomerate Marble Formation, and of an unit different to hose observed overriding he Veleta Group, which named Miñarros Unit. From bottom to top, the Southern Domain displays two alpujárride units composed of a metapelitio sequence of micaschists, phyllites and quartzites with green schist facies metamorphisrn and carbonate formation attributed to the Triassic, Over these appears an alpujárrides unit fonned of micaschists and quartzites, presumibly of Paleozoic age, exhibiting medium-grade metamorphism. Above all this there is a maláguides unit formed of a Triassic and Jurassic series essentially composed of carbonates. Recent wrench faults trending NE-SW and NNE-s5W, are responsible for the present arc-shapped disposition of the structures.