The Neuquen Basin (Argentina): Extensional Fault Reactivation During Compressional Stages, and Resulting Stratigraphic Response

G. O. Grimaldi
Texas A&M University, Dept. of Geology and Geophysics, College Station, TX

The Neuque´n Basin, Northwest Patagonia, Argentina, is a retroarc foreland basin that underwent several extensional and compressional stages of deformation during its tectonic evolution from Triassic to Quaternary time. The basin first underwent NW-SE oriented extension during Triassic to Early Jurassic time, which was followed by a NW-SE extension during Late Jurassic to Cretaceous time. Transtensional-transpressional events during Middle Jurassic time, along with shortening from latest Cretaceous to late Miocene time, gave the basin its current structural configuration. Many of the older Mesozoic extensional depocenters were tectonically inverted during these deformation phases.

The purpose of this investigation is to document the styles, location, and timing of fault reactivation and basin inversion across the central Neuque´n Basin, as well as the resultant stratigraphic relationships. Data available for the study include regional 2-D seismic lines, over 1000 km² of 3-D seismic, and information from ten wells that penetrate most of the basin-filling strata. The regional 2-D data will allow documentation of the timing and styles of compressional deformation across the basin, whereas details about growth strata and local kinematic histories during basin inversion will be examined using the 3-D seismic volumes from the central part of the basin.

Results from this project will provide important information about deformation across the Southern Andean Foreland, which may also be applicable to other foreland settings.

AAPG Search and Discovery Article #90902©2001 AAPG Foundation Grants-in-Aid