Reconstruction of the Cenozoic Deformation of North-central South America Caribbean Mountains Using 2D Thermal-Kinematic Models and Apatite Fission-track Thermochronology (Spanish Presentation)

Ana Jazmin Rodriguez Lara (presenter), Mauricio Alberto Bermúdez, Universidad Pedagógica y Tecnológica de Colombia (UPTC)

Presentation in Spanish.

In the north-central South America lies Caribbean Mountains, which runs along the central and eastern portions of Venezuela's northern coast. This chain consists of two parallel ranges: Cordillera de la Costa and the Serranía del Interior. Both orogens are the result of the collision between the Caribbean and South American plates. In this area there are few thermochronological data that allow us to reconstruct the deformation history of this chain. Our research combines 2-D Structural restoration, thermal-kinematic models, and fission-track ages, to reconstruct the deformation history of the area. Two competing models were made in the 2D MOVE® software, velocity fields were introduced in the FetKin code, to predict ages on the surface of the zone and compare them with the existing thermochronological data. The choice of the best model is made according a misfit function. Subsequently, the thermal histories of our “best” model is compared with individual t-T paths using HeFTy software. Our results are consistent with an extension and/or sedimentation. Rocks were buried until the Eocene when the Caribbean plate collide with South America. We discriminated 4 different tectonic cooling pulses: ~48 to 40 Ma, ~40 to 23 Ma and ~23 to 5 and 5 to 0 Ma. The first one is related with the convergence between the Caribbean and South American plates, causing the emplacement of the Lara Nappes (Stephan et al., 1985), the second is related to the cooling caused by the subduction of the Caribbean plate below the Caribbean deformed belt, the third phase is explained by the subduction of the Caribbean plate under the South American plate, finally the last pulse could be to related with reactivations of different faults in a transpressive context, and the Mérida Andes exhumation.

Ana Jazmin Rodriguez Lara, Universidad Pedagógica y Tecnológica de Colombia (UPTC)

Ana Jazmin will be graduating with a BSc in Geological Engineering from the Universidad Pedagógica y Tecnológica de Colombia (UPTC), and is a Laureate thesis candidate.

Ana is a member of the Colombian Geothermal Association.