Paleogeographic evolution of the Río de la Plata craton in the Precambrian: a paleomagnetic point of view

FRANCESCHINIS, PABLO R.; RAPALINI, AUGUSTO E.; CUKJATI, ANDRÉS; SANCHEZ BETTUCCI, LEDA; MILANESE, FLORENCIA N.; AFONSO, J.W.L.; TRINDADE, R.I.F.

Río de Janeiro

Congreso; LatinMag VII Biennal Meeting; 2023

Asociación Latinoamericana de Paleomagnetismo y Geomagnetismo

In the last twenty years the paleomagnetic database for the Río de la Plata craton hasincreased considerably. However, huge time intervals during the Precambrian remainwithout reliable paleomagnetic poles, which seriously limit the paleogeographiclocation of the Río de la Plata craton and its participation in the formation and breakupof the Precambrian supercontinents. On the other hand, the current database allows toprovide reliable paleomagnetic information of the craton in a short interval of thePaleoproterozoic (2.1-2.06 Ga). In this time span, three paleomagnetic poles obtainedfrom the Soca, Isla Mala and Cufré intrusives enable to infer a “non-orthodox”configuration for the Atlantica continent, that is, far from the classic Gondwana-likepaleogeographic configuration originally proposed. Therefore, with the available datathe existence of that continent prior to the formation of the supercontinent Columbiacannot be ruled out but must be revised. With the exception of a singlePaleoproterozoic pole of 1.79 Ga, which allows to produce some hypotheses about thelocation of the craton in the supercontinent Columbia, there are no reliable data untilthe Ediacaran. In this period, between 600 and 560 Ma, four reliable paleomagneticpoles allow speculating on the paleogeography of the craton in a context of Gondwanaformation. However, the global Ediacaran paleomagnetic database is hampered byinterpretations of non-actualistic geodynamic and/or geomagnetic processes.