Chapter 31 - Structural styles, tectonic evolution, and petroleum systems of transverse pre-Andean structures: examples from the Cuyo and Neuquén basins

Abstract

Transverse pre-Andean tectonic discontinuities and related Mesozoic depocenters have good preservation potential and relatively well-defined seismic images that allow a better understanding of the factors controlling basin evolution and petroleum system development. Reactivation of a low-angle fault in eastern Cuyo Basin is related to a Triassic wedge-shaped sedimentary fill and widespread second-order normal faulting that can be reactivated during later tectonic events. Long-lived high-angle faulting in the southeastern margin of the Neuquén Basin produces a thick and continuous sedimentary pile flanked by a narrow, heavily deformed belt that accommodates most of the strain during Jurassic to Cretaceous deformation episodes. These differences in structural style affects source rock potential in terms of organic matter types, burial depth, and maturity level. Reservoir properties are influenced in respect of its thickness, lateral extent, and diagenetic evolution. Pre-Andean overburden as well as foreland basin erosion and burial history are critical to understand local hydrocarbon generation and trapping.