THE WOLFRAM VALLE DE PANCANTA-LA CAROLINA BELT RELATED TO SHEAR ZONE IN SIERRAS PAMPEANAS, SAN LUIS, ARGENTINA

In the Valle de Pancanta - La Carolina region in Sierras Pampeanas, San Luis province, central western Argentina, is located a wolfram mineralized belt submeridian trending related with shear zones. In this region, an upper - mediun crustal tectonic unit that alternating with other deeper crustal tectonic unit, record the first Famatinian Deformation development like a N-S striking regional S1-foliation and shear zones of cm- to several m- wide strip of milonites with S-C fabrics and mylonite- foliation (Fmy), in granitoids and greenschist facies metamorphics rocks (San Luis Formation). These shear zones has striking NNW-SSE and sinestral sense in Valle de Pancanta, and striking NNE-SSW and dextral sense to the north, near of La Carolina; the last are conjugate shear zone and latter is probably. The shear zone are permeables structures and canalize wolframite and schellite- bearing fluids another minerals (sphalerite, galena, chalcopyrite, pyrite and bismuth) during continuous process in the time, under ductil and brittle-ductil stages. Early W-bearing quartz veins folded related S-C fabrics corresponding ductile stage. In the brittle-ductil stage are producing transtensives zones filled with W-bearing qz-veins cross-cut regional S1-foliation and C-planes; the veins thinness to disappear in transpresives zones. Pinch and swell, boudinage structure are too producing latter. Microscopically scale the veins present polycristalline quartz ribbons and undulose extinction in quartz grains; the scheelite present undulose extinction, and recristalization; the scheelite of generation early is intensely deformed with parallel strain shadows and oblique micro-fractures filled with recrystallizated zoisita. Concluding is possible to establish the Valle de Pancanta -La Carolina wolfram-bearing belt should be structurally controlled for N-S to NNE trending regional shear with sinestral sense, limited probably to the west for El Realito-Villa de La Quebrada shear zone and to the east by shear zone strip located to the east La Escalerilla Granite. This submeridional trending regional shear extends to the south to Villa de la Quebrada with wolfram-bearing veins deposits.