1. Nanomaterial accumulation in boiling brines enhances epithermal bonanzas
- Author
-
Ministerio de Ciencia e Innovación (España), European Commission, Geological Society of America, Cano, Néstor, González-Jiménez, José M., Camprubí, Antoni, Domínguez-Carretero, Diego, González-Partida, E., Proenza, Joaquín A., Ministerio de Ciencia e Innovación (España), European Commission, Geological Society of America, Cano, Néstor, González-Jiménez, José M., Camprubí, Antoni, Domínguez-Carretero, Diego, González-Partida, E., and Proenza, Joaquín A.
- Abstract
Epithermal bonanza-type ores, characterized by weight-percent contents of e.g., gold and silver in a few mm to cm, are generated by mixtures of magmatic-derived hydrothermal brines and external fluids (e.g., meteoric) that transport a variety of metals to the site of deposition. However, the low solubilities of precious metals in hydrothermal fluids cannot justify the high concentrations necessary to produce such type of hyper-enriched metal ore. Here we show that boiling metal-bearing brines can produce, aggregate, and accumulate metal nanomaterials, ultimately leading to focused gold + silver ± copper over-enrichments. We found direct nano-scale evidence of nanoparticulate gold- and/or silver-bearing ores formed via nonclassical growth (i.e., nanomaterial attachment) during boiling in an intermediate-sulfidation epithermal bonanza. The documented processes may explain the generation of bonanzas in metal-rich brines from a range of mineral deposit types.
- Published
- 2023