Southern Plateau and Itaimbezinho Canyon

Abstract

The Itaimbezinho canyon is located in the Southern Plateau, between the states of Santa Catarina and Rio Grande do Sul, in Brazil. This area, popularly known as Aparados da Serra (Mountain Range Trims), is mainly characterized by extensive vertical escarpments. The landforms in the northeastern portion of the Southern Plateau were carved from volcanic rocks of basaltic and acidic compositions that belong to the Mesozoic Serra Geral Magmatism. The effusive rocks show the existence of vertical and horizontal joints which provide preferential drainage paths, both at the plateau and within the scarp. Continuous erosion of the plateau edge has produced steep and deeply dissected relief, with scenic canyons that gradually widen to alluvial surfaces and the coastal plain. Therefore, the formation of the present relief is associated with tectonic uplift of the Southern Plateau coupled with continuous fluvial erosion.