CRUSTAL ROOT DEVELOPMENT IN TRANSPRESSION, CENTRAL RANGE FAULT SYSTEM, TRINIDAD

Trinidad is an island seven kilometers off the East coast of Venezuela. It has been proposed by Weber et al. (2001) that the Central Range fault system in Trinidad is undergoing active transpression, which would be consistent with the folds and thrusts mapped by Kugler (1959) in central Trinidad. The immature topography of the Central Range suggests a young mountain building system and offers an opportunity to test a deformation model for transpressional convergence that takes into account root development due to isostacy. The kinematic model, created using MATLAB, is a 2D simulation of the pure shear component normal to the fault and is a simplification from the more complex 3D transpression. An initial array of material points is incrementally deformed and subsequently compensated for by using the Airy isostatic model. Flow line animations are created from successive deformation increments and show both upward (exhumation) and downward (root development) movement of material. The model is applied to Trinidad where the constraints are level of exposure, relief, crust density, rate of lateral displacement and erosion. The model makes specific and testable predictions regarding gravity and exhumation rates for the Central Range fault system. The model shows potential for use as a predictive tool for analyzing other, less well constrained transpressional systems.