Tracing metal sources for the giant McArthur River Zn-Pb deposit (Australia) using lead isotopes
| Autor: | Joséphine Gigon, David L. Huston, Roger G. Skirrow, Irvine R. Annesley, Terrence P. Mernagh, Andrew S. Wygralak, Julien Mercadier, Kristian Masterman, Antonin Richard, Etienne Deloule |
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| Přispěvatelé: | GeoRessources, Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Institut national des sciences de l'Univers (INSU - CNRS), Centre de Recherches Pétrographiques et Géochimiques (CRPG), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Geoscience Australia, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Northern Territory Geological Survey (NTGS), Australian National University (ANU), Glencore Australia Holdings |
| Rok vydání: | 2020 |
| Předmět: |
Felsic
010504 meteorology & atmospheric sciences Geochemistry Geology Structural basin engineering.material 010502 geochemistry & geophysics 01 natural sciences Mantle (geology) Hydrothermal circulation Isotope fractionation Source rock [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry Galena engineering Sedimentary rock 0105 earth and related environmental sciences |
| Zdroj: | Geology Geology, Geological Society of America, 2020, 48 (5), pp.478-482. ⟨10.1130/G47001.1⟩ |
| ISSN: | 1943-2682 0091-7613 |
| Popis: | Giant hydrothermal ore deposits form where fluids carrying massive amounts of metals scavenged from source rocks or magmas encounter conditions favorable for their localized deposition. However, in most cases, the ultimate origin of metals remains highly disputed. Here, we show for the first time that two metal sources have provided, in comparable amounts, the 8 Mt of lead of the giant McArthur River zinc-lead deposit (McArthur Basin, Northern Territory, Australia). By using high-resolution secondary ion mass spectrometry (SIMS) analysis of lead isotopes in galena, we demonstrate that the two metal sources were repeatedly involved in the metal deposition in the different ore lenses ca. 1640 Ma. Modeling of lead isotope fractionation between mantle and crustal reservoirs implicates felsic rocks of the crystalline basement and the derived sedimentary rocks in the basin as the main lead sources that were leached by the ore-forming fluids. This sheds light on the crucial importance of metal tracing as a prerequisite to constrain large-scale ore-forming systems, and calls for a paradigm shift in the way hydrothermal systems form giant ore deposits: leaching of metals from several sources may be key in accounting for their huge metal tonnage. |
| Databáze: | OpenAIRE |
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