Dispersión geoquímica secundaria de metales de base en suelos de un sector de la cordillera Patagónica

BOUZA PJ; DEL VALLE HF; HALLER MJ; MEISTER CM

Salta

Congreso; XIV Cuarto Congreso Geológico Argentino; 1999

This study constitutes a preliminary analysis of the behavior pf lead, copper and zinc in soils related to different mineralized areas of the Patagonian Cordillera.  The objectives were: (i) to characterize morphologically the soil types, (ii) to determine lead, copper and zinc contents in different master soil horizons, and (iii) to evaluate secondary dispersion types in soils. There were 8 pedons with known locations within the study area (Los Cipreses, Arroyo Las Mentas, Laguna Terraplén, Cerro Riñón and Puesto Loncón).  Lead, copper and zinc contents were determined in the soil fraction <177 mm on samples of master horizons by aqua regia digestion-flame AA.  The soils ere classified as a complex of Andisols and Mollisols. Zinc showed the largest geochemical mobility by the increase of its concentration in the upper horizons and for the scarce variation of these contents among soil profiles of the same study area (lateral migration). Lead showed low mobility in Arroyo Las Mentas, where the concentration of this element diminished from a soil profile to another in function of the distance that separates them from an exploration trench with dominant galena ore. The relative mobility of copper was proved by the highest content in the soil horizons next to the copper ore mineralized regolith. Base metal analyses and detailed soil descriptions constitute an appropriate methodology to evaluate geochemical secondary dispersion types in mineralized areas.