Puncoviscana, folded belt in northwestern Argentina: testimony of Late Proterozoic Rodinia fragmentation and pre-Gondwana collisional episodes: a reply

Franz and Lucassen (2000) rise several important points, which are primaril y related to the Puncoviscana belt role in northwestern Argentina. Their di scussion consisted of three major overviews: (a) the Puncoviscana belt evol ution related to the Proterozoic Rodinia fragmentation; (b) the geochemical data associated with volcanic rock interlayered in the Puncoviscana format ion and (c) the central Andes residual gravity field interpretations. It wi ll be shown in this reply that their claim against our interpretation is th e consequence of an equivocal handling of the geological times, the tectoni c episodes and the associated lithologies in the wide context of the Puncov iscana belt type paleogeographic connections. Some present geochronological data oldest that 1.1 to 0.9 Ga. are consisten t with an autochthonous basement integrated by very ancient protoliths adjo ins to the typical Grenville belt rocks before the Rodinia fragmentation. T he autochthonous condition must be interpreted only as the Rodinia supercon tinental reality, that after remains into the new Laurentia-Cabalonia-Panno tia continental units. In this context, the Theia, Candelaria, Iapetus and other proto-oceanic rifts begins an allochthonous reality for lot of the dr ifting crustal slivers during the Pannotian Cycle, (Late Proterozoic - Earl y Paleozoic) in the break-up geotectonic times of the post-Rodinian superco ntinent. The Puncoviscana geochemical interpretation presented in this reply shows a n very clear plate tectonic evolution in various steps: (1) the proto-rift lineaments from the extensional regimen of the Candelaria triple point (t(D M) similar to0.70 to 0.78 Ga.); (2) the passive continental margin sequence s (700 to 600 Ma); and (3) the magmatic arc in the compressive regimen belo nging to the Pampean orogeny (580 to 534 Ma).