GSA Annual Meeting in Denver, Colorado, USA - 2016

Paper No. 275-4
Presentation Time: 8:50 AM


ROJAS-AGRAMONTE, Yamirka1, PROENZA, Joaquín A.2, GARCIA-CASCO, Antonio3, NEUBAUER, Franz4, LÁZARO, Concepción5, GARCÍA-DELGADO, Dora6, PÉREZ, Mireya7 and VAZQUEZ, Tania7, (1)Institut für Geowissenschaften, Johannes Gutenberg-Universität, Mainz, D-55099, Germany, (2)Universitat de Barcelona, Departament de Mineralogia, Petrologia i Geologia Aplicada, Barcelona, Spain, (3)Department of Mineralogy and Petrology, University of Granada, and Andalusian Institute of Earth Sciences, IACT, UGR-CSIC, Avenida Fuentenueva sn, Granada, 18071, Spain, (4)Geography and Geology, University of Salzburg, Hellbrunnerstraße 34, Salzburg, 5020, Austria, (5)Departamento de Mineralogía y Petrología, Universidad de Granada, Granada, 18071, Spain, (6)Centro de Investigación del Petróleo - Ceinpet, Cerro,, Ciudad de La Habana,, 12000, Cuba, (7)Instituto Superior Politécnico José Antonio Echeverría, CUJAE,, Ciudad de la Habana, 19390, Cuba,

The evolution and development of the Early Cretaceous (∼135 Ma) to Paleogene (∼46 Ma) arc systems in Cuba is the result of intra-oceanic subduction of the proto-Caribbean below Pacific lithosphere (Farallon plate). Volcano-sedimentary and plutonic rocks of predominantly low-K tholeiitic and calc-alkaline to shoshonitic affinity characterize the different island-arc units that occur in tectonic contact above and below ophiolitic rocks (west-central and eastern Cuba), and above the Guaniguanico and Caribeana terranes.

The arc section, especially in central Cuba, is almost complete and records quasi-continuous arc magmatism that developed since pre-middle Hauterivian time (pre ~133 Ma). The oldest arc-related rocks consist of unmetamorphosed primitive bimodal sequences of the Los Pasos Fm and the Mabujina Amphibolite Complex (MAC). Geochemically the Los Pasos Fm includes mostly low-Ti island arc tholeiites, normal island arc tholeiites (IAT) and M-type felsic volcanic rocks with boninitic signatures. The MAC predominantly consists of IAT basalt and basaltic andesite, gabbro and pyroclastic rocks, deformed and metamorphosed up to amphibolite-facies. Several younger intra-oceanic volcanic arc complexes/series unconformably overlie the early Cretaceous IAT lavas and include widespread Albian-Coniacian calc-alkaline and Coniacian-Campanian high-K calc-alkaline/alkaline volcanic rocks. Cretaceous volcanic units in eastern Cuba are basaltic to felsic in composition and have distinct geochemical signatures documenting fore-arc, axial-arc and back-arc environments. Fragments of the Cretaceous volcanic arc (Purial complex) underwent subduction-related metamorphism during the latest Cretaceous. Arc-related granitoid plutons with a wide range of compositions intruded the Cretaceous arc at ~104−75 Ma (Camagüey region) and at ~89−83 Ma in central and eastern Cuba.

The youngest section (Paleocene-Eocene) of the Cuban arc is mainly restricted to eastern Cuba. The magmatic axis of this arc occurs in the Sierra Maestra Mountains and mostly consist of low-K IAT and calc-alkaline lavas, suggesting an immature intra-oceanic arc environment. A large number of calc-alkaline, low- to medium-K tonalite and trondhjemite plutons and hypabyssal bodies intruded the arc sequence from ~60 to 47 Ma.