CONICET | Buscador de Institutos y Recursos Humanos

The granitic pegmatites of the Sierras de Córdoba. The granitic pegmatites of the Córdoba ranges are mainly grouped in four different economic pegmatitic fields. In three of them the pegmatites are roughly aligned in north-south trending belts known from east to west as Alta Gracia, Comechingones and Altautina pegmatite fields. The fourth, named Punilla, has pegmatites included in, or near the postorogenic Achala batholith which is emplaced telescoping the previous PT conditions in which the Pampean basement evolved. The Alta Gracia pegmatitic field contains Muscovite class pegmatites developed in a thick, mostly psamopelitic, accrecionary prism possibly during a second stage of migmatization during the Pampean orogeny and approximately emplaced at 600° C and 6-7 kbar. The Comechingones pegmatitic field has pegmatites of the Muscovite-Rare Element Class and LCT (Li-Cs-Ta) petrogenetic family, with industrial minerals and scarce U- Ta- Be-mineralization. The pegmatites are sincinematic with the Guacha Corral shear zone and they were fractionated from parental leucogranites generated possibly by partial melting of Pampean protoliths by shear heating duringthe Famatinian orogeny. The Altautina pegmatitic field encompasses pegmatites of Muscovite-Rare Element class in the north to Li-bearing Rare Element pegmatites in the south. This LCT pegmatite field possibly develops by partial melting of pelitic rocks from an accrecionary wedge at a high-T low-P Abukuma-type metamorphic episode during the latest stages of the Pampean orogeny. The Punilla pegmatitc field has preferently intragranitic NYF pegmatites of Beryl-Columbite-Phosphate subtype fractionated from the A-type Upper Devonian-Lower Carboniferous Achala graniticbatholith. These pegmatites have a very diversified accesory mineralogy of secondary origin that yield three new mineral phosphates. The magmatic stage of crystallization of these pegmatites is approximately in the range 580-530° C and 3-1,7 kbar.Keywords: muscovite-, muscovite-rare elements-classes, LCT - NYF granitic pegmatites.