Patagonian Shelf (250 to 450 km wide) where the seabed slopes gently to 200 m isobath. Apart from the Falklands Plateau (which lies to the east of the Falkland Islands), the seabed then falls by up to to 2000 m and more. The Falklands Trough separates the Patagonian Shelf from the Scotia Arc. Patagonian Shelf The Patagonian or Argentine Shelf is part of the South American continental shelf belonging to the Argentine Sea on the Atlantic seaboard, south of about 35°S. It adjoins the coasts of Uruguay, Argentina and the Falkland Islands. Various authorities quote different dimensions of the shelf, depending on
North Patagonian Massif North Patagonian Massif The North Patagonian Massif or Somún Cura Massif (Spanish: "Macizo Norpatagónico", "Macizo Nordpatagónico" or "Macizo de Somún Cura") is a massif in northern Patagonia located in the Argentine provinces of Río Negro and Chubut. The massif is a plateau surrounded by sedimentary basins. The North Patagonian Massif covers an area of approximately . The massif rises above the surrounding topography reaching a maximum of above sea level. Compared to neighboring areas, the North Patagonian Massif has thicker continental crust. The massif consists of a basement formed by Cambro-Ordovician rocks, overlain by the Middle Silurian Sierra Grande Formation.