Sierras Pampeanas

It includes cliffs and narrow channels of some rivers which are named "drawers" (if they are of moderate size) or "guns "(if they are older); there are abundant caves, grottos and overhangs.

Some mountains are separated by significant open areas (too large to be considered a "valley"); these are called "barreales" (mud-flats) or "pampas" (grassy plains).

The Sierras Pampeanas are composed of several sub-ranges: The name "Pampean Ranges" can be misleading, since the Argentine Pampas cover most of the country's northern and eastern portion.

Before the Mesozoic the Sierras Pampeanas was affected by cycles of orogenic events produced by a series continent-continent collisions along the Proto-Pacific margin of Gondwana.

Along the Pacific margin the convergence of tectonic plates lead to renewed subduction which produced the large rhyolitic provinces and plutonic belts of the Permian–Jurassic.

[1] Between 530 and 440 million years ago, during the Pampean and Famatinian orogenies the area of the Sierras Pampeanas was intruded by a series of pegmatite dykes.

[4] As the South Atlantic opened following the Paraná-Etendeka flood basalts, the Andean orogeny began the formation of the Andes, the product of volcanism and compressional forces along the Pacific margin, but also resulted in the development of extensional basins in South America and a passive margin along the Atlantic coast, processes still going on today.

Sierras Pampeanas was also affected by Miocene arc magmatism 700 km (430 mi) east of the Chile Trench during this period.

The portions within Córdoba and San Luis enjoy Mediterranean-type climate, with intense summer rainstorms and snowy winters; the vegetation here includes conifer trees.

There are short, torrential rivers and many streams and rivulets that carry low flows, with brief and violent floods caused by summer rains.

The observed fauna varies according to the combination of three basic natural factors: the arrangement of mountain ranges, altitude and climate.

In the fertile plains of Tucumán Province previously were found rhea, turkey, parrot, hummingbird, woodpecker and pigeons.

Shrubs and medicinal herbs grown in the Sierras de Córdoba include peperina, pennyroyal, dandelion, plantain, canchalagua, wild grapes, chamomile, malva, lime and passion fruit.

In arid areas such as the center and west of La Rioja and Catamarca, irrigated vines thrive, and large plantations of olive trees, (jujube was brought by Lebanese immigrants and Syrians in early twentieth century), grains, aloe and jojoba.