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. 2019 Aug 5;10(1):3511.
doi: 10.1038/s41467-019-11065-4.

A metasomatized lithospheric mantle control on the metallogenic signature of post-subduction magmatism

David A Holwell  1 , Marco Fiorentini  2 , Iain McDonald  3 , Yongjun Lu  2   4 , Andrea Giuliani  5 , Daniel J Smith  6 , Manuel Keith  6   7 , Marek Locmelis  8
Affiliations

A metasomatized lithospheric mantle control on the metallogenic signature of post-subduction magmatism

David A Holwell et al. Nat Commun. .

Abstract

Ore deposits are loci on Earth where energy and mass flux are greatly enhanced and focussed, acting as magnifying lenses into metal transport, fractionation and concentration mechanisms through the lithosphere. Here we show that the metallogenic architecture of the lithosphere is illuminated by the geochemical signatures of metasomatised mantle rocks and post-subduction magmatic-hydrothermal mineral systems. Our data reveal that anomalously gold and tellurium rich magmatic sulfides in mantle-derived magmas emplaced in the lower crust share a common metallogenic signature with upper crustal porphyry-epithermal ore systems. We propose that a trans-lithospheric continuum exists whereby post-subduction magmas transporting metal-rich sulfide cargoes play a fundamental role in fluxing metals into the crust from metasomatised lithospheric mantle. Therefore, ore deposits are not merely associated with isolated zones where serendipitous happenstance has produced mineralisation. Rather, they are depositional points along the mantle-to-upper crust pathway of magmas and hydrothermal fluids, synthesising the concentrated metallogenic budget available.

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Conflict of interest statement

The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Trans-lithospheric post-subduction chalcophile element profiles. Primitive mantle-normalised chalcophile element profiles as explained in (a) for: b-d mantle rocks from the Ivrea Zone (b), xenoliths from the Bultfontein kimberlite (c) and Lihir (d); e lower crustal intrusions; f mid-crust intrusions; g upper crustal magmatic–hydrothermal porphyry systems and h epithermal systems. Note: “a” indicates data from this study, whereas other data are cited in reference list. Normalisation values are from Palme and O’Neill
Fig. 2
Fig. 2
Tellurium/nickel and copper ratios through the lithosphere. a Plot of Te vs. Ni showing increase in Te/Ni up through the lithosphere with fractionation; and b plot of Te vs. Cu showing divergent behaviour in the hydrothermal environment
Fig. 3
Fig. 3
Metallogenic evolution of post-subduction magmatism. a Schematic representation of post-subduction magmatic setting; b idealised representation of hydrous alkaline magmatic systems that stage in the lower, mid or upper crust, as well as associated representative mineral deposits; c representative chalcophile element profile for each of the scenarios shown in b
See this image and copyright information in PMC

References

    1. Richards JP. Postsubduction porphyry Cu-Au and epithermal Au deposits: products of remelting of subduction-modified lithosphere. Geology. 2009;37:247–250. doi: 10.1130/G25451A.1. - DOI
    1. Richards JP. Magmatic to hydrothermal metal fluxes in convergent and collided margins. Ore Geol. Rev. 2011;40:1–26. doi: 10.1016/j.oregeorev.2011.05.006. - DOI
    1. Locmelis M, et al. Sulfur and metal fertilization of the lower continental crust. Lithos. 2016;244:74–93. doi: 10.1016/j.lithos.2015.11.028. - DOI - PMC - PubMed
    1. Fiorentini ML, et al. Post-collisional alkaline magmatism as gateway for metal and sulfur enrichment of the continental lower crust. Geochim. et. Cosmochim. Acta. 2018;223:175–197. doi: 10.1016/j.gca.2017.11.009. - DOI
    1. Tomkins AG, et al. Magmatic sulfide formation by reduction of oxidized Arc basalt. J. Petrol. 2012;53:1537–1357. doi: 10.1093/petrology/egs025. - DOI