The Dom Feliciano belt is a tectonic unit of southern Brazil, Uruguay, and a portion of Argentina's Pampas region. Its internal geological organization shows three narrow and sub-parallel crustal segments: a granite belt at the southeastern end; a central schist belt; and a northwestern foreland belt with volcano sedimentary sequences.
The crystalline rock belt of Dom Feliciano tectonic unit is formed by a series of essentially igneous complexes, of the which the Pelotas batholith in the State of Rio Grande do Sud is the most representative. It was formed in a magmatic arc tectonic environment. The granitoid rocks include a series of deformed calc-alkaline types (tonalite, granodiorite, etc) and many weakly deformed and non-deformed monzogranite. The schist belt include supracrustal rocks in a few discontinuous polydeformed metamorphic complexes.
The crystalline terrains observed in the northern and central-western parts of Dom Feliciano belt are those of Luiz Alves and Rio de la Plata. The Luiz Alves cratonic fragment is a microplate, in which high grade metamorphic rocks are abundant. Meanwhile, the Rio de la Plata craton includes different terrains with ages of formation older than the neo-proterozoic, such as the Tacuarembo-Rivera, Nico Perez, Piedras Altas, and Tandil in the province of Buenos Aires (Argentina). The Tandil terrain constitutes a highly deformed crystalline basement.
