Late Cretaceous and Paleogene evolution of the Greater Antilles fold- and thrustbelt: structure and stratigraphy in the Camagüey region, Cuba
Abstract
The northern Caribbean margin underwent arc-continent collision in the late Cretaceous and Paleogene. On Cuba this les to the stacking of tectonic slices that comprise from top to bottom a volcanic arc unit, an ophiolite complex, a deformed belt of sedimentary rocks (the Camajuaní and Placetas belts) and finally rocks correlative to the Bahamas platform on the southern North American continental margin. On south-central and western Cuba, HP-LT metasedimentary rocks, on the Isle of Pines including a HT-LP overprint, were exhumed in the course of the late Cretaceous, probably at least partly added by extensional unroofing. These metamorphic rocks are exhumed in tectonic windows in the ophiolite and volcanic arc tectonic slices. Their exhumation quite surprisingly coincided with the arrest in arc volcanism in the Cuban periphery. Here, we present an integrated structural geological and stratigraphic study of the sedimentary units incorporated in the basal parts and underlying the ophiolite unit in the Camagüey province in northern central Cuba. Aim of this study was to constrain the direction and timing of compressional deformation contemporaneous with and following the exhumation and possibly extension in the southern internal parts of the Cuban fold-and thrust belt, and with the arrest in arc volcanism. Our results indicate that the Placetas belt in the Camagüey region consist of tightly, polyphase folded deep marine upper Jurassic to upper Cretaceous limestones, forming isolated blocks incorporated in a tectonic mélange at the base of the ophiolite unit. Timing of their deformation is likely late Cretaceous and younger. The Bahamas platform-related carbonates in the Sierra de Cubitas at the base of the Cuban nappe stack are characterized by a single, open folding phase trending sub-parallel to the main NW-SE trending structural grain of the fold- and thrust belt. This deformation marks the arrest in emplacement of the Cuban nappe stack onto the southern North American continental margin in the Mid-Eocene. (Under-)thrusting hence continued after the late Cretaceous into the Mid-Eocene, i.e. well after the arrest of arc volcanism and exhumation of metamorphic rocks in the internal parts of the Cuban collage. We will discuss the implications of this study for the northern Caribbean subduction history
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2007
- Bibcode:
- 2007AGUFM.T13C1470V
- Keywords:
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- 8005 Folds and folding;
- 8038 Regional crustal structure;
- 8104 Continental margins: convergent;
- 8108 Continental tectonics: compressional;
- 8170 Subduction zone processes (1031;
- 3060;
- 3613;
- 8413)