Monte Desert Monte Desert The Monte Desert is a South American ecoregion, lying entirely within Argentina and covering approximately the submontane areas of Catamarca, La Rioja, San Juan, San Luis and Mendoza Provinces, plus the western half of La Pampa Province and the extreme north of Río Negro Province. The desert lies southeast of the Atacama Desert in Chile, north of the larger Patagonian Desert, east of the Andes and west of the Sierra de Córdoba. The delineations between the Monte Desert, the Atacama Desert, and the Patagonian Desert are not exact and the desert seems to be more-or-less continuous with the
Patagonian Desert contributing to the gravel sediments covering parts of the Patagonian. The desert is quite windy as well, a result of the rain shadow effect and descending cool mountain air. This wind helps make the Patagonian one of the largest sources of dust over the South Atlantic Ocean. On the west the Patagonian grasslands portion of the Patagonian Desert are bounded by nothofagus forests of the Magellanic subpolar forests. Volcanic rocks covers more than 120,000 km of the Patagonian Desert, mainly in the "Somun Cura Massif" (i.e. North Patagonian Massif) and the "Deseado Massif". Some other volcanic areas include the Pali-Aike