The Precambrian drift history and paleogeography of Río de la Plata craton

Paleomagnetismo, estratigrafia magnética e sedimentologia do Ediacarano na Formação Avellaneda (Argentina)

“…The superposition of the poles of these cratons suggests that they were already united or very close to each other in the middle Ediacaran (Rapalini et al, 2021), weakening the model of a large Clymene Ocean for those times (eg. Rapalini et al, 2015).…”

“…Paleomagnetic constraints on the paleogeographic evolution of the Río de la Plata craton (RPC) in the Precambrian is limited to three time-spans (Rapalini et al, 2021). The first of them is restricted to the Rhyacian, between 2.11 and 2.05 Ga (Rapalini et al, 2015;Franceschinis et al, 2019).…”

“…The second time span occurs during the Statherian and correspond to the 1790 Ma pole of Teixeira et al (2013) obtained from the Florida tholeitic dyke swarm exposed in the Piedra Alta terrane, Uruguay. Finally, a third group of paleomagnetic poles and VGPs (Rapalini et al, 2013(Rapalini et al, , 2015(Rapalini et al, , 2021 correspond to the Ediacaran, coeval with the assembly of Gondwana (600-550 Ma, Meert, 2014). The first paleomagnetic studies in Precambrian units of the Tandilia system, southern Río de la Plata craton, were carried out by Valencio et al (1980) in sedimentary units assigned at that time to the La Tinta Formation (current Sierras Bayas group).…”

“…In the last twenty years, an apparent polar wander path (APWP) has been constructed with a total of six polar positions from paleomagnetic poles and VGPs for the Rio de la Plata craton (Rapalini et al, 2013;Rapalini, 2018). This path suggests that the craton was at low, nearly equatorial, latitudes at around 600 Ma and drifted to intermediate latitudes by 575 Ma, possibly already attached to or very close to the Congo-São Francisco and NW Africa cratons (Rapalini et al, 2021). By around 550 Ma, the RPC was apparently still at intermediate latitudes.…”

“…Despite this progress on the Ediacaran apparent polar wander path of the Río de la Plata craton that has placed some constraints on its paleogeographic evolution and the timing and kinematics of Western Gondwana assembly (e.g. Rapalini, 2018;Rapalini et al, 2021), the paleomagnetic database is still scarce for robust and precise paleogeographic reconstructions.…”