Orogeny in 1890 to describe the process of mountain building as distinguished from epeirogeny. The formation of an orogen can be accomplished by the tectonic processes such as oceanic subduction (where a continent rides forcefully over an oceanic plate for accretionary orogeny) or continental subduction convergence of two or more continents for collisional orogeny). Orogeny usually produces long arcuate (from the Latin "", "to bend like a bow") structures, known as "orogenic belts". Generally, orogenic belts consist of long parallel strips of rock exhibiting similar characteristics along the length of the belt. Although orogenic belts are associated with subduction zones, subduction
Pampean orogeny monzogranites, and volcanic rocks, all of them of calc-alkaline chemistry. The igneous rocks of this belt formed at various times in over the period from 555 to 525 million years ago. From 525 million years ago onward another magmatic belt of peralumineous and mafic rocks developed further amidst gneiss, schist, amphibolites and carbonate rocks. The igneous rocks of this belt formed in the period from 525 to 515 million years ago. The Pampean orogeny can be considered part of the larger Terra Australis orogeny or of the Brasiliano orogeny. The Pampean orogeny developed at a similar time as the Paraguai