Physical Sciences and Mathematics Commons^™

Multiple Migmatite Events And Cooling From Granulite Facies Metamorphism Within The Famatina Arc Margin Of Northwest Argentina, Sean R. Mulcahy, Sarah M. Roeske, William C. Mcclelland, Joshua R. Ellis, Fred Jourdan, Paul R. Renne, Jeffrey D. Vervoort, Graciela I. Vujovich

Geology Faculty Publications

The Famatina margin records an orogenic cycle of convergence, metamorphism, magmatism, and extension related to the accretion of the allochthonous Precordillera terrane. New structural, petrologic, and geochronologic data from the Loma de Las Chacras region demonstrate two distinct episodes of lower crustal migmatization. The first event preserves a counterclockwise pressure-temperature path in kyanite-K-feldspar pelitic migmatites that resulted in lower crustal migmatization via muscovite dehydration melting at ∼12 kbar and 868°C at 461 ±1.7 Ma. The shape of the pressure temperature path and timing of metamorphism are similar to those of regional midcrustal granulites and suggest pervasive Ordovician migmatization throughout the …