The Golfo San Jorge Basin () is a hydrocarbon-rich sedimentary basin located in eastern Patagonia, Argentina. The basin covers the entire San Jorge Gulf and an inland area west of it, having one half located in Santa Cruz Province and the other in Chubut Province. The northern boundary of the basin is the North Patagonian Massif while the Deseado Massif forms the southern boundary of the basin. The basin has largely developed under condition of extensional tectonics, including rifting.
The basin is of paleontological significance as it hosts six out of 22 defining formations for the SALMA classification, the geochronology for the Cenozoic used in South America.
At the center of the basin accumulated sediments reach more than of thickness. Oil was first discovered in 1907 and over the years it has become the second most productive hydrocarbon basin in Argentina after Neuquén Basin.
Stratigraphy The stratigraphy of the Golfo San Jorge Basin covers the following units:Raigemborn et al., 2010, p.243Cortés, 1986, p.49
Unit Age Tectonic regime Depositional environment Thickness(m) Petroleum geology Tehuelche Shingle Pleistocene Glacio-fluvial 40 Río Mayo Mayoan Santa Cruz Santacrucian Fluvio-deltaic 200 Patagonia Shallow marine 280 Sarmiento Colhué Huapí Mb.Chenque Colhuehuapian Fluvio-lacustrine 120 Deseadan Tinguirirican Río Chico Koluel Kaike Divisaderan Lacustrine 42 Mustersan CasamayorLas Flores Casamayoran Fluvio-lacustrine 44 Peñas Coloradas Riochican Fluvial 42 Itaboraian Las Violetas Peligran 25 Salamanca Peligran Shallow marine-deltaic-fluvial 200 Petroleum reservoir Tiupampan Lago Colhué Huapí MaastrichtianCampanian Fluvial Yacimiento El TrébolMeseta EspinosaBajo BarrealLaguna Palacios SantonianAptian Late sag DeltaicFluvio-lacustrine 4000+ Cañadón SecoComodoro RivadaviaBajo Barreal Alluvial-fluvial-lacustrine Mina El CarmenCastillo Fluvio-lacustrine Pozo D-129Matasiete Early sag 1500+ Source rock and petroleum reservoir Pozo Cerro Guadal Neocomian Late rift Fluvio-lacustrine 560 Pozo Anticlinal Aguada Bandera Lacustrine 1700+ Source rock Bahía LauraLonco Trapial Cerro Carnerero Mid-Late Jurassic Early rift Volcaniclastic 1300+ Early Jurassic Pre-rift Shallow marine 700+ Basement Paleozoic
See also Cañadón Asfalto Basin Magallanes Basin South American land mammal ages
References
Bibliography General
Cretaceous
Paleogene Andesitas Huancache Formation
Bororó Formation
Casamayor Formation
Las Flores Formation
Koluel Kaike Formation
Peñas Coloradas Formation
Río Chico Group
Salamanca Formation
Neogene Río Mayo Formation
Sarmiento Formation & Colhué Huapí Member
Further reading