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The Paleoproterozoic Era is represented in South America by a noteworthy diversity of records, both in major tectonic blocks/terranes as well as in the reworked basement of younger provinces. The sequence of events can be established according to the ICS-IUGS geologic time division.
The paleogeography of these blocks/terranes is far from being known, but it is admitted that all of them were assembled in the composition of the Rodinia supercontinent. This is a permissive premise, but it does not constitute an obstacle for the identification of several orogenic and anorogenic events in time, from the Siderian to the Orosirian.
Along the Siderian records of events of granulite-gneiss belt formation between 3.5 and 3.0 Ga are found in several blocks (Amazonian, S. Francisco, Granja, Almas-Natividade, Luis Alves). These are mobile belts including a variety of igneous rocks (from ultramafic to granitic), many with Archean protoliths. Detailed (geologic and isotopic) studies lack and also of integration of these events, which is a remarkable characteristic of this continent.
The Rhyacian presents rich and varied records in all blocks. The orogenic events (collisional > > accretionary) are conspicuous in the eastern portion of the Amazonian block, in the eastern and western portions of the Sanfranciscan block, in Rio de La Plata and in the basement of the Brasiliano provinces. Reworking of the Archean protoliths is very common. There are, however, some belts and rock assemblages of juvenile accretion (including some greenstone belts). The record of sedimentation events is varied in tectonic, instability (graywackes, arkoses) and stability conditions.
The Orosirian is well represented in the central-eastern portions of the Amazonian block (Ventuari-Tapajós belt), with several identified island arcs. There are some occurrences of Rhyacian collisional orogenies with epilogue in the Orosirian (2.08-2.03 Ga). The anorogenic events are of major importance and varied throughout the continent, especially on the wide platformal areas formed at the end of the Rhyacian. It is worth mentioning the LIP Uatumã (ca.1.86-1.88 Ga) and its sub-horizontal cover ? Roraima Supergroup (ca. 1.87-1.86), which occupies more than 1,100,000 km2 of the Amazonian block. Late-orogenic and anorogenic plutonism (mostly granitic) was intense in all blocks (between 1.8 and 1.9 Ga). The first records of carbonatitic complexes are of this age.
The sole Statherian record of (accretionary) orogenies is that of the Rio Negro-Juruena belt, in the Amazonian block, as a probable southern continuity of the Transcontinental orogenic belt. Throughout the other Paleoproterozoic blocks widespread anorogenic events prevail, with varied magmatism: granites, gabbro-anorthosites, dike swarms, rift-related bimodal volcanism, and epicontinental sedimentation. Some of these records were deformed by later orogenies, but some of these rock assemblages are still preserved.
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