Sub-Andean Thrust Systems: Section Restoration, Forward Modelling and Implications for Basement Involved Thrust Systems

Abstract

In the Sub-Andean regions there are good examples of basement involved thrust systems, which result in hybrid thin and thick-skinned structures. The restoration of cross-sections from this area (with geometric and kinematic methods plus mechanical ones), as well as its forward modelling, should provide information about how the shortening is accommodated (especially within the basement) and the interaction and relationship between the basement-involved structures (thick skinned) and the thin-skinned ones generated in the cover. The results should also help choosing between the two end-member models that have proposed for the region, one which implies the reactivation of previous extensional fault and another one based on duplexes. Another interesting fact of this zone is the notable amounts of uplift produced by a limited horizontal shortening. To understand this situation we studied the relationship between shortening, uplift and fault dip. The expression relating these parameters provides a way to make estimations of one of them by knowing the other two. So, it is possible to get a broad idea of, for example, the shortening undergone by a region, measuring the fault dip and the uplift it produces.

AAPG Datapages/Search and Discovery Article #90189 © 2014 AAPG Annual Convention and Exhibition, Houston, Texas, USA, April 6–9, 2014