Fifty-five-million-year history of oceanic subduction and exhumation at the northern edge of the Caribbean plate (Sierra del Convento mélange, Cuba)

Petrological and geochronological data of six representative samples of exotic blocks of amphibolite and associated tonalite-trondhjemite from the serpentinitic melange of the Sierra del Convento (eastern Cuba) indicate counterclockwise P-T paths typical of material subducted in hot and young subduction zones. Peak conditions attained were 750 � C and 15 kbar, consistent with the generation of tonalitic partial melts observed in amphibolite. A tonalite boulder provides a U-Pb zircon crystallization age of 112.8 ± 1.1 Ma, and Ar ⁄ Ar amphibole dating yielded two groups of cooling ages of 106-97 Ma (interpreted as cooling of metamorphic ⁄ magmatic pargasite) and 87-83 Ma (interpreted as growt…