The Cabo de la Vela Mafic-Ultramafic Complex, Northeastern Colombian Caribbean region: a record of multistage evolution of a Late Cretaceous intra-oceanic arc

Abstract

AbstractOphiolite-related rocks accreted to Caribbean Plate margins provide insights into the understanding of the intra-oceanic evolution of the Caribbean Plate and its interaction with the continental margins of the Americas. Petrological, geochemical and isotope (K–Ar, Sr and Nd) data were obtained in serpentinites, gabbros and andesite dykes from the Cabo de la Vela Mafic–Ultramafic Complex from the Guajira Peninsula, in the northernmost Colombian Caribbean region. Field relations, metasomatic alteration patterns and whole rock–mineral geochemistry combined with juvenile isotope signatures of the different units suggest that gabbros and serpentinites formed in a slow-spreading supra-subduction zone that was brought to shallower depths and subsequently evolved to an arc setting where andesitic rocks formed with little sediment input. The tectonomagmatic evolution of the Cabo de la Vela Mafic–Ultramafic Complex involved an intra-oceanic arc that evolved from pre-Campanian time to 74 Ma. Relationships with other units from the Guajira Peninsula show either the existence of a mature arc basement or a series of coalesced allocthonous arcs, juxtaposed before accretion onto the passive continental margin of South American in pre-Eocene times.