An Overview of the Amazonian Craton Evolution: Insights for Paleocontinental Reconstruction

The Amazonian craton major accretionary and collisional processes may be correlated to supercontinent assemblies developed at several times in the Earth history. Based on geologic, structural and paleomagnetic evidence paleocontinent reconstructions have been proposed for Archean to younger times. The oldest continent (Ur) was formed probably by five Achaean cratonic areas (Kaapvaal, Western Dhawar, Bhandara, Singhhum and Pilbara cratons). Geologic evidences suggest the participation of the Archaean rocks of the Carajás region in the Ur landmass. Supercontinental 2.45 Ga Kenorland amalgamation is indicated by paleomagnetic data including Laurentia, Baltica, Australia, and Kalahari and Kaapvaal cratons. There is no evidence indicating that Amazonian craton was part of the Kenorland supercontinent. From 1.83 Ga to 1.25 Ga Columbia and Hudsonland supercontinents including Amazonian craton were proposed based on NE portion of the Amazonian craton (Maroni/Itacaiunas province) connection with West Africa and Kalahari cratons. Rodinia supercontinent reconstructions show Amazonia joined to Laurentia-Baltica as result of 1.1 Ga to 1.0 Ga fusion based on the Sunsas-Aguapei belts and Greenville and Sveconorwegian belts, respectivelly. The large Late Mesoproterozoic landmass included also Siberia, East Antartica, West Nile, Kalahari, Congo/Sao Francisco and Greenland. The 750 - 520 Ma Gondwana assembly includes most of the continental fragments rifted apart during the break-up of Rodinia followed by diachronic collisions (Araguaia, Paraguay and Tucavaca belts). The supercontinent Pangea is comprised of Gondwana and Laurentia formed at about 300 - 180 Ma ago. The Amazonian craton margins probably were not envolved in the collisional processes during Pangea because it was embebed in Neoproterozoic materials. As consequence, Amazonian craton borders have no record of the orogenic processes responsible for the Pangea amalgamation.