Patagonian Desert albeit to the west, where precipitation is higher, bushes are replaced by grasses. Topographically the deserts consist of alternating tablelands and massifs dissected by river valleys and canyons. The more western parts of the steppe host lakes of glacial origin and grades into barren mountains or cold temperate forests along valleys. Inhabited by hunter-gatherers since Pre-Hispanic times, the desert faced migration in the 19th century of Mapuches, Chileans, Argentines, Welsh, and other European peoples, transforming it from a conflictive borderland zone to an integral part of Argentina, with cattle, sheep and horse husbandry being the primary land uses. The Patagonian
North Patagonian Massif contains the Miocene (Colloncuran) Collón Cura Formation, the Miocene La Pava Formation, and the Miocene Chimehuín Formation in the northern part of the eastern belt. 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