Interpretación geodinámica del metamorfismo de ultra-alta presión en las peridotitas de Ronda

Abstract

We repon the occurrence of several minerals representative of high to ultra-high pressure metamorphism in the Sierta Bermeja massif of the Ronda peridotites (Betic Cordilleras, southern Spain). Some of them, like graphite pseudomorphs after diamonds and corundum in garnet pyroxenites were already known; others, like garnet blebs in orthopyroxene porphyroclasts and inclusions in garnet ofcoesite pseudomorphs or of clinopyroxene and acicular rutile in three sets at 120°, are described here. These minerals attest for a nearly adiabatic decompression path starting from asthenospheric levels within the diamond stability field. We propose that this event of mantle exhumation took place in a continental rift setting related to the latera.1 motion between the African and Iberian plates during Mesozoic times