Geochemistry of the Santa Fé Batholith and Buriticá Tonalite in NW Colombia – Evidence of subduction initiation beneath the Colombian Caribbean Plateau

• DOI: 10.1016/j.jsames.2015.04.002
• Publication Date: 2015-05-11T21:04:51Z
• Authors: M. Weber; J. Gómez-Tapias; A. Cardona; E. Duarte; A. Pardo-Trujillo; V.A. Valencia
• Keywords: Batholith; Continental Margin; Island arc

Abstract Plateau related rocks accreted to the 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. Petrologic, geochemical and isotope (Sr and Nd) data were obtained in rocks from the Santa Fe Gabbro-Tonalite and Buritica Tonalite in the Western Cordillera of Colombia. Field relations and whole rock–mineral geochemistry combined with juvenile isotope signatures of the different rocks present in the area, suggest that initial melts, represented by the Buritica Tonalite, formed due to asthenospheric upwelling at ∼100 Ma, which intrude the Colombian-Caribbean Oceanic Plateau (CCOP) basalts, and subsequent migration of the Caribbean plate towards the northeast resulted in subduction initiation and the formation of the Santa Fe tonalitic units at ∼90 Ma on the CCOP. The relation of the Santa Fe Batholith with other units from the Caribbean, such as Aruba and the Buga Batholiths suggests the existence of an immature arc constructed on the Caribbean Plateau, which partially accreted onto a continental margin of South American in pre-Eocene times, or migrated to the present day position in the Lesser Antilles.