Provenance, sediment accumulation history and refined regional chronostratigraphy for the San Jorge Basin, Chubut Province, Argentina

Abstract

The San Jorge Gulf Basin produces 47% of Argentina’s liquid hydrocarbons, 90% of this production comes from the Cretaceous Bajo Borreal Formation, Chubut Group (Parades et al, 2015). Despite the economic significance of the San Jorge petroleum system, provenance, high-resolution age control, linked outcrop-to-subsurface stratigraphic architecture, and sediment accumulation histories remain elusive for the region. The San Jorge reservoir units comprise the earliest Andean foreland basin deposits of Northern Patagonia and record a transition from continuous to broken foreland conditions during changing slab-dynamics (Gianni et al, 2015). Research undertaken in 2018 on the equivalent stratigraphy in Northern Chubut province, partially supported by AAPG GIA 2018, demonstrates 1) depositional ages are younger than previously recognized and 2) abrupt transitions in provenance correspond to changes in subduction dynamics (Butler et al, in prep, Journal of South American Earth Sciences). The North Patagonian Broken Foreland is situated between two of Argentina’s significant petroleum provinces, the Neuquén and Magallanes-Austral basins. Refining the regional tectonic history will enhance future exploration and development within these basins. I propose a high-resolution analysis of the nonmarine Cretaceous to marine Paleogene clastic stratigraphy of the San Jorge Gulf Basin. I will use a multi-disciplinary approach, including a 3D network of measured sections, provenance analyses, and 2D seismic outcrop-to-subsurface correlations. The proposed locality provides a unique opportunity to refine the early foreland basin history and petroleum system development of Northern Patagonia

AAPG Datapages/Search and Discovery Article #90351 © 2019 AAPG Foundation 2019 Grants-in-Aid Projects