%0 Journal Article
%A Rapela, Carlos W.
%A Fanning, C.M.
%A Casquet, César
%A Pankhurst, R.J.
%A Spalletti, Luis
%A Poiré, Daniel
%A Baldo, Edgardo G.
%T The Rio de la Plata craton and the adjoining Pan-African/brasiliano terranes: Theirorigins and incorporation into south-west Gondwana
%D 2011
%@ 1342-937X
%U https://hdl.handle.net/20.500.14352/43854
%X The Neoproterozoic to Early Cambrian amalgamation of SW Gondwana through the Brasiliano/Pan-Africanorogeny is reviewed with emphasis on the role of the Río de la Plata craton of South America in the light ofnew evidence from a borehole at the eastern end of the Tandilia belt (38°S). U–Pb, Hf and O isotope data onzircon indicate that this un-reworked Palaeoproterozoic craton abuts against a distinct continental terrane tothe east (Mar del Plata terrane). The craton is bounded everywhere by transcurrent faults and there is noevidence to relate it to the Neoproterozoic mobile belts now seen on either side. The Punta MogotesFormation at the bottom of the borehole contains 740–840 Ma detrital zircons that are assigned to awidespread Neoproterozoic rifting event. The data suggest that the Mar del Plata terrane rifted away from thesouthwestern corner of the Angola block at c. 780 Ma. Negative εHft values and δ18O N6.5‰suggest derivationby melting of old crust during a protracted extensional episode. Other continental terranes may have formedin a similar way in Uruguay (Nico Pérez) and southeastern Brazil, where the Schist Belt of the Dom Felicianoorogenic belt is probably a correlative of the Punta Mogotes sequence, implying that the Dom Feliciano beltmust extend at least as far as 38°S. A new geodynamic scenario for West Gondwana assembly includes at leasttwo major oblique collisional orogenies: Kaoko–Dom Feliciano (580–680 Ma) and Gariep–Saldania (480–580 Ma), the latter resulting from oblique impingement of the Rio de la Plata craton against the Kalaharicraton. Assembly of this part of South-West Gondwana was accomplished before the Ordovician (to Silurian?)siliciclastic platform sediments of the Balcarce Formation in the Tandilia Belt covered the southern sector ofRío de la Plata craton.
%~