Paleomagnetism of the Amazonian Craton and its role in paleocontinents Paleomagnetismo do Cráton Amazônico e sua participação em paleocontinentes

In the last decade, the participation of the Amazonian Craton on Precambrian supercontinents has been clarified thanks to a wealth of new paleomagnetic data. Paleo to Mesoproterozoic pale- omagnetic data favored that the Amazonian Craton joined the Co- lumbia supercontinent at 1780 Ma ago, in a scenario that resembled the South AMerica and BAltica (SAMBA) configuration. Then, the mismatch of paleomagnetic poles within the Craton implied that ei- ther dextral transcurrent movements occurred between Guiana and Brazil-Central Shield after 1400 Ma or internal rotation movements of the Amazonia-West African block took place between 1780 and 1400 Ma. The presently available late-Mesoproterozoic paleomagnetic data are compatible with two different scenarios for the Amazonian Craton in the Rodinia supercontinent. The first one involves an obli- que collision of the Amazonian Craton with Laurentia at 1200 Ma ago, starting at the present-day Texas location, followed by transcurrent mo- vements, until the final collision of the Amazonian Craton with Baltica at ca. 1000 Ma. The second one requires drifting of the Amazonian Craton and Baltica away from the other components of Columbia after 1260 Ma, followed by clockwise rotation and collision of these blocks with Laurentia along Grenvillian Belt at 1000 Ma. Finally, although the time Amazonian Craton collided with the Central African block is yet very disputed, the few late Neoproterozoic/Cambrian paleomagne- tic poles available for the Amazonian Craton, Laurentia and other West Gondwana blocks suggest that the Clymene Ocean separating these blocks has only closed at late Ediacaran to Cambrian times, after the Amazonian Craton rifted apart from Laurentia at ca. 570 Ma.