Abstract
In southern Chile, with a mild and rainy climate, high levels of heavy metals have been detected in many gold placer deposits. Many of the contaminants pose risks to human life, and consequently damage the trofic chain in this environment. The study zones selected correspond to the handicraft gold-bearing sands of Rio Gato (Los Muermos), Carelmapu and Cucao. These are all located in the X Region of “Los Lagos” in Chile. The type of methodology used in the characterization of the associated mineralization consists of testing each representative sample with a grain size distribution, statistical parameter analysis and a mineralogical analysis, using a binocular magnifying glass, a petrographic microscope, XRD and SEM/EDX. The chemical composition was defined by means of X ray fluorescence and micro-chemical analysis. The results of the study about sediments in southern Chile are presented. The major concentrations of heavy minerals are generally located in areas of dynamic river energy. In the samples, more than 70% of the heavy minerals were distributed among grain sizes corresponding to thin sand with good grain selection (meshes of 0.25–0.06 mm). The main mineral phases present in the analysed samples were gold, zircon, olivine, ilmenite, hornblende, hypersthene, hematite, garnet, chromite, chlorite, augite, amphibolitic-epidote, etc. The main heavy metals found as a result of the study were mercury, lead, cadmium, chrome, tellurium, indium, zinc, cobalt, copper, platinum, gold, etc., and as well some less common elements like cerium, praseodymium, gadolinium, neodymium, samarium and lanthanum. This research work is only a starting point for carrying out a risk probability mapping of heavy metals and the mineralogy of the Cucao, Carelmapu and Rio Gato gold-bearing sands.
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References
Castro SH, Sanchez M (2003) Environmental viewpoint on small-scale copper, gold and silver mining in Chile. J Cleaner Prod 11(2):207–213
Davis BL (1980) A study of the errors in X-ray quantitative analysis procedures for aerosols collected on filter media. Atmos Environ 15:291–296
Davis BL (1981) Quantitative analysis of crystalline and amorphous airborne particulates in the Provo-Orem Vicinity, Utah. Atmos Environ 15:613–618
Davis BL (1984) X-ray diffraction analysis and source apportionment of Denver aerosol’. Atmos Environ 18(10):2197–2208
González I, Hevia M, Balocchi C, Sanfeliu, T, Prieto M, Quiroz M, Olivo P (1999a) Detección de mercurio y gases contaminantes en placeres auríferos chilenos. III Conferencia Internacional de la Metalurgia de los Metales Preciosos y IV Conferencia Nacional sobre Metalurgia del Oro y la Plata. Oruro, Bolivia
González I, Jordán M, Prieto M, Quiroz M, Olivo P (1999b) Prospección de oro, platino y mercurio mediante análisis microquímico en placeres de la X Región, Chile. III Conferencia Internacional de la Metalurgia de los Metales Preciosos y IV Conferencia Nacional sobre Metalurgia del Oro y la Plata. Oruro, Bolivia
González I, Prieto M, Sanfeliu T, Jordán M, Olivo P (2000) Determinación de minerales pesados asociados a depósitos secundarios auríferos de la X Región, Chile. II Seminario Internacional: Gas Natural en la Industrialización del Hierro-Acero y otros Metales. Cusco, Perú
González I, Jordán MM, Sanfeliu T (2002) Mineralogía y geoquímica de metales pesados contaminantes presentes en suelos mineros del Sur de Chile. Espaço Geografia 5(1):249–266
Herail G, Lagos J, Vivillo W (1999) Gold dispersión in Andean desert environments (Atacama, Chile). J Geochem Explor 66(3):427–439
Higueras P, Oyarzún R, Lillo J, Oyazún J, Maturana H (2005) Atmospheric mercury data for the Coquimbo region, Chile: influence of mineral deposits and metal recovery practices. Atmos Environ 39(39):7585–7596
Higueras P, Oyarzún R, Oyarzún J, Maturana H, Lillo J (2004) Environmental assessment of copper–gold–mercury mining in the Andacollo and Punitaqui districts, northern Chile. Appl Geochem 19(11):1855–1864
Johnson CB, McQueen KG (2001) The nature of gold-bearing paleochannel sediments in the Gidji area north of Kalgoorlie, Western Australia. Quat Int 82:51–62
Olivo P (2000) Prospección geoquímica y mineralógica de áreas favorables para explotar oro y minerales pesados, X Región Chile. Thesis. Universidad Tecnológica Metropolitana, Santiago, Chile
Oyarzún R, Lillo J, Higueras P, Oyarzun J, Maturana H (2004) Strong arsenic enrichment in sediments from Elqui watershed, Northern Chile: industrial (gold mining at El Indio-Tambo district) vs. geologic processes. J Geochem Explor 84(2):53–64
Parada MA, Palacios C, Lahsen A (1997) Jurassic extensional tectono-magmatism and associated mineralization of the El Faldeo polymetallic district, Chilean Patagonia: geochemical and isotopic evidence of cristal contribution. Miner Depos 32(6):547–554
Prieto M (2000) Estudio sedimentológico, mineralógico y geoquímico de los placeres auríferos de Cucao, X Región Chile. Thesis. Universidad Tecnológica Metropolitana, Santiago, Chile
Quiroz M. (2001) Estudio Geoquímico y Mineralógico de los Placares Auríferos de Carelmapu, X Región, Chile. Thesis. Universidad Tecnológica Metropolitana, Santiago, Chile
Ruiz C, Peebles F. (1988) Geología, distribución y génesis de los yacimientos metalíferos Chilenos. Editorial Universitaria, Santiago, Chile
Sillitoe RH (2003) Iron oxide–copper–gold deposits: an Andean view. Miner Depos 38(7):787–812
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The present study makes known part of the information obtained during the realization of Projects 108/98 “Prospección de Yacimientos Secundarios de Oro y Evaluación de la Contaminación Producto de su Explotación” and 269/04 UTEM-Empresa, financed by the Universidad Tecnológica Metropolitana de Chile (UTEM).
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González, I., Jordán, M.M., Sanfeliu, T. et al. Mineralogy and heavy metal content in sediments from Rio Gato, Carelmapu and Cucao, Southern Chile. Environ Geol 52, 1243–1251 (2007). https://doi.org/10.1007/s00254-006-0562-0
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DOI: https://doi.org/10.1007/s00254-006-0562-0