Patagonian Desert whom 3,000 ended up in Buenos Aires separated by sexes to avoid their procreation. The boundary treaty of 1881 between Chile and Argentina bought most of the desert under definitive Argentine sovereignty; previously Chile had claimed varying now Argentine areas under claims of inherited colonial titles. In the few decades before and after 1900 the less dry parts of the Patagonian steppe experienced a sheep farming boom, transforming the region into one of the world's greatest exporters of ovine products. The area is sparsely populated today and those that do live here survive mainly by the raising of livestock such
Patagonian Desert Volcanic Field near the Strait of Magellan. The volcanic rocks are the result of back-arc volcanism distributed mainly in two episodes: one in the Eocene and Miocene and the other from Late Miocene to Pleistocene. Despite the harsh desert environment, a number of animals venture into and live in the Patagonian. Some only live on the more habitable and geographically-varied outskirts of the desert, where food is more abundant and the environment less hostile, but all are found within the region encompassing the Patagonian. The burrowing owl, lesser rhea, guanaco, tuco-tuco, mara, pygmy armadillo, Patagonian weasel, puma, Patagonian gray fox,