Western Caribbean Structural Provinces Based on 2D Kinematic Restorations of the Lower Nicaraguan Rise and Colombia Basin

Abstract

The Caribbean region covers only 0.4 percent of the world's surface, but has an extremely complex tectonic history due to the interaction of the North American, South American, and Pacific plates. Four high-resolution, kinematically-restored, 2D seismic sections (3250 km) recreate the structural conditions in the Lower Nicaraguan Rise and Colombian Basin since the Middle Cretaceous (~93 Ma). In the study area, we observed three structural styles: (a) a transtensional style identified by regional strike-slip faults in the Hess Escarpment and the Pedro Bank Fault Zone; (b) an extensional style observed as block rotation and normal faulting in the San Andres Rift and the Lower Nicaraguan Rise; and (c) a compressional style represented by thrust faulting in the South Caribbean Deformed Belt (SCDB).

Our results indicate that: (1) the Hess Escarpment, a sinistral strike-slip fault with a total length of 1200 km, was active primarily during the Late Cretaceous to the Early Eocene, while the southwestern segment remains active today. Extensional deformation along the fault ranges from 18 to 20 percent, and is associated with negative flower structures that have a maximum sinistral displacement of 150 km. (2) The Pedro Bank fault zone, a Late Miocene to Recent sinistral strike-slip fault with a total length of 1300 km, exhibits negative flower structures with a total extension of 13 percent and a maximum sinistral displacement of 180 km. (3) The San Andres Rift, a pull-apart basin caused by the extension of the Pedro Bank Fault Zone, has been breaking up since the Late Miocene and has a current extension of 23%. (4) The SCDB, an accretionary prism created by the subduction of the Caribbean oceanic plate, shows a maximum shortening of 35 percent where compression started in Early Eocene.

AAPG Datapages/Search and Discovery Article #90219 © 2015 GCAGS, Houston, Texas, September 20-22, 2015