Thermal evolution of the eastern Serrania del Interior foreland fold and thrust belt, northeastern Venezuela, based on apatite fission track analyses
Locke, Brian David
Avé Lallemant, Hans G.
Master of Arts
Apatite fission track data show a gradual decrease in age (∼30 Ma to ∼15 Ma) from north to the south in the eastern SerranIa del Interior, northeastern Venezuela. Based on a previous study, a model for the tectonic evolution of the eastern SerranIa is proposed in which two stages of deformation occurred. Stage 1 (45 Ma--20 Ma) involves the internal deformation of fault blocks. Stage 2 (20 Ma--12 Ma) involves envelopment thrusting, doubling the thickness of the thrust sheet. Shortening within the SerranIa del Interior ceased at 12 Ma. In stage 1, cooling and exhumation rates were 5.8°C/km and 0.26 km/my, respectively, and in stage 2, cooling and exhumation rates were 4.25°C/km and 0.2 km/my, respectively. The deformation of the SerranIa prior to the collision of the Caribbean plate with South America is probably related to the convergence of the North and South American plates.