The Andean Santander-Oriental Tectonic Syntaxis: A First-Order Pattern Controlling Exploration Play-Model Concepts In Colombia

The Santander and Oriental ranges form an Andean tectonic syntaxis along the central eastern part of Colombia being its internal compressive occidental compartment constituted by the more competent pre- Mesozoic (as well as the Garzon and Nevado del Cocuy massif). Easterwards this area, regarded as a spur surrounded by the arched Mid-Upper Cretaceous to Tertiary fold and thrust belt which convexity is projected towards the eastern foreland. Due to the oblique ENE Andean convergence on the Pacific border of the South American plate, the northern Santander branch - trending NNW - shows leftlateral transpressive tectonics. Contrastingly, the southern Cordillera Oriental branch - trending SSW - shows right-lateral transpressive tectonics. The interaction with the foreland exhibits a fold and thrust belt with relevant wrenching expressed by en-echelon multi-scalar structures. At present, the Mesozoic and Tertiary depocenters are dismembered by the action of this first-order pattern tectonics into several relictic isolated portions. These basin segments show different local structural geometries depending on their relationships with the major extensional pre-Tertiary as well as their Andean reactivation and inversion structures. This tectonic pattern difficults the traditional geometrical balancing of conceptual section across the entire Andean cordilleras and affects the petroleum system models improving reservoir and migration conditions of the diverse plays along the main tectonic corridors.