CARACTERIZACIÓN DE LAS ROCAS DE SKARN Y GREISSEN RELACIONADAS AL CONTACTO BASAMENTO METAMÓRFICO - GRANITO PAPACHACRA, CATAMARCA, ARGENTINA.

LAZARTE J. ENRIQUE, HORTA LUIS R.

San Salvador de Jujuy

Congreso; XVII Congreso Geológico Argentino; 2008

Comision Organizadora del XVII Congreso Geológico Argentino

ABSTRACT The Papachacra Granite, in contact with Loma Corral Formation generates skarn and greissen rocks. They locate in Belén department, Catamarca province, centred on 45º S, 45º W.  This paper deals with its geologic and geochemistry characterization. The Loma Corral Formation is low grade metamorphic rocks (metasedimentary, metavolcanic and marbles). Skarn constituent are  epidote, muscovite, garnet, malaquite, pyrite, quartz and Fe oxides (mainly magnetite). There are two kinds of greissen rocks, a fluorite – magnetite ribbon rock (exo greissen) and the other, a quartz – sericite – topaz grissen. The geochemistry of skarns is lower Y, Th, U and REE, and higher Ba, Sr, Cr, Pb, Cu, Zn, V and Ti than the granite. Other values are Sn >2 <300, W >2 <20, Rb/Sr<2, Ba/Rb >1 <300, Th/U ≈ 5. Greissens have high values of As, Sb, Bi, Be, Li, Sn y W.   Other values are Sn and W >20, Rb/Sr >1 <100, Ba/Rb >0,05 <0,5, Th/U >0,8 <11. Hidrothermal veins are high W, Cu, Pb (Zn) with Sn >10, W between 20 and 200 p.p.m. Palabras clave: skarn, greisen, granito especializado, mineralización, geoquímica. Key words: skarn, greissen, specializated granite, mineralization, geochemistry.