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Fast switch from extensional exhumation to thrusting of the Ronda Peridotites (South Spain)
Author(s) -
Frasca Gianluca,
Gueydan Frédéric,
Poujol Marc,
Brun JeanPierre,
Parat Fleurice,
Monié Patrick,
Pichat Alexandre,
Mazier Sophie
Publication year - 2017
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/ter.12255
Subject(s) - geology , crust , lithosphere , mantle (geology) , subduction , continental crust , tectonics , rift , geochemistry , extensional tectonics , petrology , seismology
Abstract The Alboran Domain, situated at the western end of the Mediterranean subduction system, is characterized by the Ronda Peridotites, one of the world's largest exposures of sub‐continental mantle. Using U–Pb ( LA ‐ ICP ‐ MS ) and Ar–Ar dating, we precisely dated two tectonic events associated with the Tertiary exhumation of the Ronda Peridotites. First, shearing along the Crust–Mantle Extensional Shear Zone caused, at ca. 22.5 Ma, mantle exhumation, local partial melting in the deep crust and coeval cooling in the upper crust. Second, the Ronda Peridotites Thrust triggered the final emplacement of the peridotites onto the continental crust at c . 21 Ma, as testified by granitic intrusions in the thrust hangingwall. The tectonic evolution of the western Alboran Domain is therefore characterized by a fast switch from continental lithospheric extension in a backarc setting, with sub‐continental mantle exhumation, to a rift inversion by thrusting driven by shortening of the upper plate.