Evolución tectónica del basamento paleozoico de la Patagonia y la Plataforma continental adyacente

RAMOS, VICTOR; NAIPAUER MAXIMILIANO; LOVECCHIO, JUAN PABLO

MENDOZA

Congreso; 11º Congreso de Exploración y Desarrollo de Hidrocarburos; 2022

Instituto Argentino de Petrñoleo y Gas

This paper describes the tectonic evolution of Patagonia and the adjacent continental shelf basedon the different behavior of its continental margins. The Pacific margin is characterized by a complextectonic evolution where each segment has a geological development during the Paleozoic with itsown characteristics. The northern sector is characterized by a typical Andean-type evolution wherethe subduction of the oceanic crust produces a Devonian magmatic arc of a continental nature,which towards the Carboniferous was located closer to the trench. The central sector records thecollision of an island arc, recognized as the Chaitenia terrane, with magmatism more primitive andcharacteristic of an oceanic setting. This island arc collided in the Late Devonian-Early Carboniferousagainst Patagonia. The late Paleozoic magmatism that followed migrated towards the foreland andis recorded further south in the subsurface of the San Jorge Gulf basin. The southernmost sectorrecords the collision of the Antarctic Peninsula, possibly in the middle Permian according to the ageof metamorphism, which exposes rocks from 10 to 12 kilometers depth. The complexity observed inthe Paleozoic active margin contrasts with the Atlantic margin which is characterized by a conjugatepassive margin similar to the Eastern Antarctic margin. This margin is preserved on the continentalshelf below the Mesozoic sequences. These Paleozoic deposits are slightly deformed along theeastern edge of Patagonia. The exception is the northern sector, which was affected by the collisionof Patagonia against Gondwana at the end of the Paleozoic.