%0 Journal Article
%A Verdecchia, Sebastián
%A Casquet Martín, César
%A Baldo, Edgardo G.
%A Pankhurst, R.J.
%A Rapela, Carlos W.
%A Fanning, C.M.
%A Galindo Francisco, María Del Carmen
%T Mid- to Late Cambrian docking of the Rı´o de la Plata craton to southwesternGondwana: age constraints from U–Pb SHRIMP detrital zircon ages from Sierrasde Ambato and Velasco (Sierras Pampeanas, Argentina)
%D 2011
%@ 0016-7649
%U https://hdl.handle.net/20.500.14352/42077
%X The Early Palaeozoic stratigraphy and tectonic history of the Eastern Sierras Pampeanas of centralArgentina are complicated by metamorphism and deformation resulting from the Pampean (545–510 Ma) andFamatinian (490–440 Ma) orogenies. We report U–Pb sensitive high-resolution ion microprobe dating ofdetrital zircons in two metasedimentary successions exposed at Quebrada de La Ce´bila (c. 28845’S, 66825’W):the Ambato and the La Ce´bila metamorphic complexes. The Ambato zircons record age peaks correspondingto Pampean (530  10 Ma), Brasiliano (c. 570 and c. 640 Ma), Grenville (c. 950 to c. 1025 Ma) and minorNeoarchaean ages. Similar peaks are also apparent in the La Ce´bila sample but it additionally containsPalaeoproterozoic zircons (c. 2.1 Ga) corresponding to the age of the Rio de la Plata craton, from which theyare considered to have been sourced. Our interpretation is that the protolith of the Ambato complex wasdeposited prior to juxtaposition with the craton and is older than the Early Ordovician La Ce´bila metamorphiccomplex. We infer that the craton reached its current relative position in the Mid- to Late Cambrian, after themain Pampean tectonothermal event (530–520 Ma) and before deposition of the La Ce´bila protolith and theAchavil Formation (Sierra de Famatina), which contain comparable detrital zircon populations.
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