A POST-PAMPEAN MIDDLE TO LATE CAMBRIAN SILICICLASTIC PLATFORM ON THE PROTO-ANDEAN MARGIN OF GONDWANA AND ITS PALEOGEOGRAPHICAL IMPLICATIONS

CASQUET , C.; RAPELA, C.W.; PANKHURST, R.J.; BALDO, E.; GALINDO, C.; VERDECCHIA, S.; DAHLQUIST, J.A.; MURRA, J.; FANNING, C.M.

Oviedo

Simposio; GEOLOGÍA DE LA CORDILLERA DE LOS ANDES Y SU ANTEPAÍS. Geology of the Andean Cordillera and its foreland.; 2012

Sociedad Geológica de España

The Early to Late Ordovician Famatinian orogeny along the western margin of Gondwana was preceded at the latitude of the present Sierras Pampeanas of Argentina by the sedimentation of a post-Pampean orogeny (Early Cambrian) siliciclastic wedge on a continental shelf. Sedimentation of the clastic wedge apparently took place in two stages: one prior to final inland dextral docking of the Rio de la Plata craton in the Middle to Late Cambrian and a second one, involving the provenance of detrital zircons from the craton, in the Late Cambrian. This second episode of clastic sedimentation may be correlated on the basis of detrital zircons with at least part of the siliciclastic Balcarce Formation that overlies the Rio de la Plata craton.