%0 Journal Article
%A Baldo, Edgardo G.
%A Casquet, César
%A Galindo Francisco, Mª del Carmen
%T Datos preliminares sobre el metamorfismo de la Sierra de Pie dePalo, Sierras Pampeanas Occidentales (Argentina)
%D 1998
%@ 0213-683X
%U https://hdl.handle.net/20.500.14352/56926
%X The Sierra de Pie de Palo belongs to the Western Sierras Pampeanas. Although still poorly known indetail, the sierra consists of a relatively autochthonous sequence of shelf sediments metamorphosed tolow grade (the Caucete Group) and an allochthonous complex of polymetamorphic medium-to-highgrade igneous and sedimentary rocks thrust towards the west and northwest. Mylonitization is widespread.Radiometric dating by different methods (U-Pb, 4°Ar/39Ar and K-Ar) suggests that at least two tectonothermalevents are present in the allochthonous: Grenville (ca. 1 Ga) and Famatinian (480-312Ma).Metamorphism has been studied in a Ca-rich pelite with a complex mineralogical composition(Qtz, Ms, Pg, Bt, Grt, Ky, Hbl, St, Rt, 111, PI, Ep). This rock is a mylonite. Three metamorphic stages arerecognized: the first two correspond to a prograde M, metamorphism under relatively high P/T conditions(peak at 13kb and about 600ºC). The second is related to mylonitization (Mm 1) with T - 575ºC and P< 1 Okb. We suggest that this rock is polymetamorphic, M, metamorphism beirig probably related to theGrenville orogeny and Mmyl to the Famatinian orogeny.
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