The University of Southampton
University of Southampton Institutional Repository

A new discrimination scheme for oceanic ferromanganese deposits using high field strength and rare earth elements

A new discrimination scheme for oceanic ferromanganese deposits using high field strength and rare earth elements
A new discrimination scheme for oceanic ferromanganese deposits using high field strength and rare earth elements
Ferromanganese (Fe-Mn) deposits constitute a ubiquitous mineral type in oceanic settings, with metal (Cu, Ni, Zn, Co, Pt) and rare earth element (REE) enrichments of potential economic interest. Routine analysis of trace elements by ICP-MS has advanced our understanding of the impact of hydrogenetic, diagenetic and hydrothermal processes on the mobility and interaction of high field strength elements (HFSE: Zr and Ti) and REE and yttrium (REY) with Fe-Mn oxyhydroxides. Recent discoveries in the French exclusive economic zone (EEZ) of Wallis and Futuna (southwest Pacific Ocean) have brought new insight into the formation of low temperature (LT) hydrothermal Mn deposits and lead us to reconsider the classification and discrimination diagrams for Fe-Mn deposits and ore-forming processes. Using a suite of LT hydrothermal Fe-Mn crusts from Wallis and Futuna, we investigate how contrasting genetic processes influence the distribution of metals (Mn, Fe, Cu, Ni, and Co), HFSE and REY in hydrogenetic, diagenetic, hydrothermal and mixed-type deposits from different environments in the global ocean. The interaction of the different metal oxide-forming processes indicates that: (i) enrichment of Co, HFSE and REY is favored by hydrogenetic precipitation, (ii) diagenetic processes produce higher Mn, Cu, and Ni concentrations with oxic remobilization in the sedimentary column, while suboxic conditions promote greater Mn and Fe remobilization that competes with the incorporation of Cu and Ni ions in nodules. HFSE and REY derived from seawater are usually low in diagenetic precipitates, which discriminate between hydrogenetic and diagenetic inputs within nodules, (iii) hydrothermal Fe-Mn deposits show strong depletion in HFSE and REY due to rapid formation and high contents of either Fe or Mn oxides. We present a new discrimination scheme for the genetic types of Fe-Mn deposits using a 10 ∗ (Cu + Ni + Co) − 100 ∗ (Zr + Y + Ce) − (Fe + Mn) / 4 ternary diagram. The use of HFSE and REY in the classification allows for a more robust discrimination of: (i) each ore-forming process with well-delimited fields, without overlap of metal-rich hydrothermal samples and hydrogenetic samples, (ii) oxic and suboxic diagenesis within nodules, (iii) trends between hydrogenetic and diagenetic end-members forming a continuum, and (iv) mixed genetic types such as the presence of hydrothermal particles within hydrogenetic crust layers. Alternatives are also explored to adapt our discriminative diagram to elements measurable by on-board instruments to aid in exploration at sea.
0169-1368
3-15
Josso, P.
7da4acf5-b481-49df-931e-160d4ed199e5
Pelleter, E.
f564f6fa-5b28-41e6-85c6-8b6f6096b97d
Pourret, O.
81d9ee7f-a9b8-4970-bfbd-7f7433079c4e
Fouquet, Y.
0a25b9d2-0250-4835-b51a-a70a479103de
Etoubleau, J.
2fd54151-1149-43e6-b566-28e0055dc586
Cheron, S.
f6aa9c01-f6f0-4a1d-af39-4a56943a097a
Bollinger, C.
c7b76c3a-bcb3-4d48-a1be-47cfbbe23746
Josso, P.
7da4acf5-b481-49df-931e-160d4ed199e5
Pelleter, E.
f564f6fa-5b28-41e6-85c6-8b6f6096b97d
Pourret, O.
81d9ee7f-a9b8-4970-bfbd-7f7433079c4e
Fouquet, Y.
0a25b9d2-0250-4835-b51a-a70a479103de
Etoubleau, J.
2fd54151-1149-43e6-b566-28e0055dc586
Cheron, S.
f6aa9c01-f6f0-4a1d-af39-4a56943a097a
Bollinger, C.
c7b76c3a-bcb3-4d48-a1be-47cfbbe23746

Josso, P., Pelleter, E., Pourret, O., Fouquet, Y., Etoubleau, J., Cheron, S. and Bollinger, C. (2017) A new discrimination scheme for oceanic ferromanganese deposits using high field strength and rare earth elements. Ore Geology Reviews, 87, 3-15. (doi:10.1016/j.oregeorev.2016.09.003).

Record type: Article

Abstract

Ferromanganese (Fe-Mn) deposits constitute a ubiquitous mineral type in oceanic settings, with metal (Cu, Ni, Zn, Co, Pt) and rare earth element (REE) enrichments of potential economic interest. Routine analysis of trace elements by ICP-MS has advanced our understanding of the impact of hydrogenetic, diagenetic and hydrothermal processes on the mobility and interaction of high field strength elements (HFSE: Zr and Ti) and REE and yttrium (REY) with Fe-Mn oxyhydroxides. Recent discoveries in the French exclusive economic zone (EEZ) of Wallis and Futuna (southwest Pacific Ocean) have brought new insight into the formation of low temperature (LT) hydrothermal Mn deposits and lead us to reconsider the classification and discrimination diagrams for Fe-Mn deposits and ore-forming processes. Using a suite of LT hydrothermal Fe-Mn crusts from Wallis and Futuna, we investigate how contrasting genetic processes influence the distribution of metals (Mn, Fe, Cu, Ni, and Co), HFSE and REY in hydrogenetic, diagenetic, hydrothermal and mixed-type deposits from different environments in the global ocean. The interaction of the different metal oxide-forming processes indicates that: (i) enrichment of Co, HFSE and REY is favored by hydrogenetic precipitation, (ii) diagenetic processes produce higher Mn, Cu, and Ni concentrations with oxic remobilization in the sedimentary column, while suboxic conditions promote greater Mn and Fe remobilization that competes with the incorporation of Cu and Ni ions in nodules. HFSE and REY derived from seawater are usually low in diagenetic precipitates, which discriminate between hydrogenetic and diagenetic inputs within nodules, (iii) hydrothermal Fe-Mn deposits show strong depletion in HFSE and REY due to rapid formation and high contents of either Fe or Mn oxides. We present a new discrimination scheme for the genetic types of Fe-Mn deposits using a 10 ∗ (Cu + Ni + Co) − 100 ∗ (Zr + Y + Ce) − (Fe + Mn) / 4 ternary diagram. The use of HFSE and REY in the classification allows for a more robust discrimination of: (i) each ore-forming process with well-delimited fields, without overlap of metal-rich hydrothermal samples and hydrogenetic samples, (ii) oxic and suboxic diagenesis within nodules, (iii) trends between hydrogenetic and diagenetic end-members forming a continuum, and (iv) mixed genetic types such as the presence of hydrothermal particles within hydrogenetic crust layers. Alternatives are also explored to adapt our discriminative diagram to elements measurable by on-board instruments to aid in exploration at sea.

This record has no associated files available for download.

More information

Accepted/In Press date: 1 September 2016
Published date: 1 July 2017

Identifiers

Local EPrints ID: 412848
URI: http://eprints.soton.ac.uk/id/eprint/412848
ISSN: 0169-1368
PURE UUID: 945cd9fb-d153-4642-a13a-5b6bda51a9a5

Catalogue record

Date deposited: 03 Aug 2017 16:30
Last modified: 27 Apr 2022 10:00

Export record

Altmetrics

Contributors

Author: P. Josso
Author: E. Pelleter
Author: O. Pourret
Author: Y. Fouquet
Author: J. Etoubleau
Author: S. Cheron
Author: C. Bollinger

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×