U-Pb SHRIMP zircon dating of Grenvillian metamorphism in Western Sierras Pampeanas (Argentina): correlation with the Arequipa Antofalla craton and constraints on the extent of the Precordillera Terrane

CASQUET, C.; PANKHURST, R.J.; FANNING, C.M.; BALDO, E.; GALINDO, C.; RAPELA, C.W.; GONZÁLEZ-CASADO, J.M.; DAHLQUIST, J.A.

GONDWANA RESEARCH

Elsevier

Año: 2006 vol. 9 p. 524 - 529

1342-937X

Metamorphism of Grenvillian age (ca. 1.2 Ga; U-Pb zircon dating) is recognized for the first time in the Western Sierras Pampeanas (Sierra de Maz). Conditions reached granulite facies (ca. 780ºC and ca. 780 MPa). Comparing geochronological and petrological characteristics with other outcrops of Mesoproterozoic basement, particularly in the northern and central Arequipa–Antofalla craton, we suggest that these regions were part of a single continental crustal block from Mesoproterozoic times, and thus autochthonous or parautochthonous to Gondwana. Key words: Sierras Pampeanas, Argentina, metamorphism, U-Pb SHRIMP zircon dating, Grenville.