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RESUMEN IntroducciónEl desarrollo y uso del bronce en el Area Andina fue un fenómeno del Horizonte Medio. La difundida explotación de menas complejas de cobre, arsénico, estaño y níquel y la producción por vez primera de un rango de bronces a gran escala durante este período, tal vez constituyen una marca tecnológica distintiva de dicho Horizonte.¿Qué significa el término "bronce" y cómo se puede hablar de un "rango de bronces"? Los bronces son aleaciones de cobre con otros metales. Estas aleaciones comparten ciertas propiedades físicas o mecánicas. El "bronce clásico" es la aleación de cobre con estaño y en los Andes se acostumbra asociar el bronce estañífero con el Imperio incaico. Ahora sabemos que el bronce estañífero fue producido mucho más temprano, durante el Horizonte Medio.Además, existen otras aleaciones que son verdaderos bronces: por ejemplo la aleación binaria compuesta de dos metales -cobre y arsénico-llamada "bronce arsenical" y una aleación ternaria y bastante rara, compuesta de tres metales -cobre, arsénico y níquel (Lechtman

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With a focus on bronze production in the south-central Andes during the Middle Horizon, this study reports the first archaeological use of lead isotope analysis to investigate metallic ores and metal artifacts in the Andean zone of South America. Because the vast majority of metal deposits in the Andean cordillera formed in a convergent plate boundary setting, lead isotope compositions of most Andean ore sources are not unique. Lead isotope ratios of central and south-central Andean ores define four geographically distinct ore lead isotope provinces, oriented and elongated parallel or sub-parallel to the trend of the Andean cordilleras. Consequently, ore lead isotope ratios vary strongly from west to east along transects through the coast, highlands and altiplano, but they exhibit much less variation from north to south. The strong west-to-east variation in ore lead isotope signatures allows discrimination between ore bodies, and ultimately between metal artifacts, as a function of macro-ecozone location: coast, junga-qiswa, puna, altiplano. We present the most up-to-date database of ore lead isotope signatures for the south-central Andes including those determined for ores we sampled over an approximate 250,000 km sq region within Bolivia, N. Chile, and NW Argentina. Lead isotope signatures of Cu-As-Ni bronze artifacts from Tiwanaku (altiplano capital) and San Pedro de Atacama (desert oasis entrepôt) establish that altiplano and high sierra ore bodies provided the metal for both assemblages. Conchopata (Wari) arsenic bronze artifacts exhibit lead isotope ratios compatible with the Julcani (Huancavelica) copper sulfarsenide deposit.