275 Geologic Evolution of Cuba

Wednesday, 28 September 2016
8:00 AM - 12:00 PM
Mile High Ballroom 2A/3A

EARLY CRETACEOUS TO PALEOGENE ARC ROCKS OF CUBA

Paper number: 275-5
Program: Technical Sessions
Time: 8:50 AM – 9:05 AM

Authors

Abstract

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.

Geological Society of America Abstracts with Programs. Vol. 48, No. 7

doi: 10.1130/abs/2016AM-282211

© Copyright 2016 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.