Copper isotope evidence for a Cu-rich mantle source of the world-class Jinchuan magmatic Ni-Cu deposit

Abstract

A Cu-rich mantle source may play a key role in generating giant magmatic Ni-Cu deposits worldwide, but evidence for source's Cu enrichment and its mechanism is still rare. Copper isotopes can provide novel and direct insights into this issue since metasomatism that causes Cu enrichment in the mantle is commonly associated with a huge Cu isotope fractionation. Here we present the first Cu isotopic study on the world-class Jinchuan magmatic Ni-Cu deposit in China, including disseminated, net-textured and massive sulfides. The disseminated and net-textured sulfides have variable δ 65 Cu values (+0.36 ± 0.38‰, n=42), which are higher than those of massive sulfides (−0.44 ± 0.28‰, n=11). The country rocks have a narrow This is the peer-reviewed, final accepted version for American Mineralogist, published by the Mineralogical Society of America.The published version is subject to change. Cite as Authors (Year) Title. American Mineralogist, in press.

Experimental Investigation on the Transport of Sulfide Driven by Melt-rock Reaction in Partially Molten Peridotite

“…Sulfide is a ubiquitous phase in the mantle (Alard et al, 2011) and an important repository for sulfur and geochemically and economically important chalcophile metals, which plays a pivotal role in the partitioning behaviors of PGE, Cu, and Ni (Mungall & Brenan, 2014;Patten et al, 2013). Understanding the factors that control the fate of sulfide phases in the partially molten mantle is of fundamental importance in exploring the recycling of sulfur and chalcophile elements among different geochemical reservoirs (Ding & Dasgupta, 2017;Farquhar et al, 2002;Yao et al, 2018;Chen et al, 2022) and identifying the re-fertilization of the depleted lithospheric mantle, which potentially provides the metal endowment for the formation of Cu-rich porphyry and/or Ni-rich magmatic ore system (Holwell et al, 2022;Lee & Tang, 2020;Mungall et al, 2015;Zhao et al, 2022). However, it remains highly contentious for the driving forces of the transport of metal-bearing sulfide liquid, which severely blocks our understanding of the details of fertilization processes that occurred in the sources of sulfiderelated magmatic and hydrothermal deposits.…”

Experimental Investigation on the Transport of Sulfide Driven by Melt‐Rock Reaction in Partially Molten Peridotite

“…Sulfide is a ubiquitous phase in the mantle (Alard et al., 2011) and an important repository for sulfur and geochemically and economically important chalcophile metals, which plays a pivotal role in the partitioning behaviors of PGE, Cu, and Ni (Mungall & Brenan, 2014; Patten et al., 2013). Understanding the factors that control the fate of sulfide phases in the partially molten mantle is of fundamental importance in exploring the recycling of sulfur and chalcophile elements among different geochemical reservoirs (Chen et al., 2022; Ding & Dasgupta, 2017; Farquhar et al., 2002; Yao et al., 2018) and identifying the re‐fertilization of the depleted lithospheric mantle, which potentially provides the metal endowment for the formation of Cu‐rich porphyry and/or Ni‐rich magmatic ore system (Holwell et al., 2022; C. T. A. Lee & Tang, 2020; Mungall et al., 2015; Zhao et al., 2022). However, it remains highly contentious for the driving forces of the transport of metal‐bearing sulfide liquid, which severely blocks our understanding of the details of fertilization processes that occurred in the sources of sulfide‐related magmatic and hydrothermal deposits.…”

New Potential Sulfide Reference Materials for Microbeam S‐Fe‐Cu Isotope Measurements

“…Sulfur (S), iron (Fe) and copper (Cu) are ubiquitous elements with different oxidation states that are heterogeneously distributed throughout reservoirs (Sawaki et al 2018, Paiste et al 2022, Smith et al 2022, McLoughlin et al 2023. The S-Fe-Cu isotope systems in sulfides have been well proven to be excellent geochemical tracers in diverse fields of geoscience, such as research on planetary evolution events, mineralisation mechanisms, hydrothermal activity and bioenvironmental processes (Li et al 2010, Marin-Carbonne et al 2014, Mount et al 2022, Hiebert et al 2016, Brzozowski et al 2021, Yu et al 2021, Lehmann et al 2022, Zhao et al 2022.…”