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Seafloor massive sulfides primary resource

Naturally occurring polymetallic sulfide deposit material formed at or beneath the seafloor by hydrothermal mineralization. This resource includes heterogeneous sulfide-bearing ore and associated gangue, rather than a single mineral species, constituent element, finished metal commodity, or processing residue. USGS distinguishes this hydrothermal resource from polymetallic nodules and cobalt-rich ferromanganese crusts. The curated experiment used collected Japanese marine hydrothermal ores, not seawater alone or pure synthetic sulfides. Their compositions are sample-specific and do not define a universal resource grade. Collection, grinding and washing leave the feed a primary resource. No constituent criticality designation is inherited; the laboratory mechanism does not establish seafloor extraction or industrial deployment.

Microbial & Biochemical Mechanisms (1)

Acidianus brierleyi culture-associated copper and zinc leaching from marine hydrothermal ore

bioleaching Microbial

Living, ore-adapted Acidianus brierleyi DSM 1651 cultures increased aqueous copper and zinc extraction from characterized sulfide-bearing ore relative to the source-designated sterile controls. In the sample A Figure 1 experiment, the paper reports approximately 85% copper and 80% zinc extraction after 10 days, versus approximately 4% and 20%, respectively, without inoculation. These are percentages calculated from measured liquid concentrations and the initial ore metal content, not purified-metal recovery. Culture growth and leaching are consistent with iron/sulfur-oxidizing activity; the proposed contributions of cell attachment, ferric-mediated chemical dissolution and sulfur oxidation are not independently isolated by these experiments. Residual sulfides remain, and the result does not apply uniformly to every metal or ore.

Experimental Context & Analytical Limits:
The paper describes ores A, B and C collected from marine hydrothermal deposits near Japan without resolving exact collection sites. Feed was ground, sieved to 38–53 µm, washed twice with distilled water and dried at room temperature. XRD identifies sphalerite, chalcopyrite, galena and montmorillonite; sample A contains 45.4 wt% SiO2 by the source table. The DSM 1651 culture was adapted by serial transfers, with similar leaching after the eighth transfer. Laboratory batch tests used 200 cm3 medium in 500 cm3 baffled flasks, 100 rpm and 65°C; some separate runs used an aerated stirred vessel. Modified medium omitted added elemental sulfur and ferrous sulfate and included 0.5 kg/m3 yeast extract. Figure 1 used initial loading 5 kg/m3, 1.0 × 10^13 cells/m3 and initial pH 1.8; Results 3.1 reports pH 1.8 ± 0.3. Other experiments varied starting pH, loading, inoculum and salt separately. Liquid metal analysis used ICP emission spectroscopy and atomic absorption, with optical free-cell counts. The study includes uninoculated controls but does not report biological replicate counts, uncertainty bars or a detailed sterilization procedure. Matching initial conditions does not establish equal pH/redox histories. Neither the culture's terrestrial origin nor laboratory ore collection establishes in situ operation.
Curated Evidence Points:
Methods 2.1–2.2 and Table 1 establish natural mixed ore, living DSM 1651 culture, preparation and assay. Results 3.1 and the rendered Figure 1 distinguish sample A copper/zinc inoculated curves from sample A sterile curves and sample B zinc. The text supplies the approximate day-10 values retained here. Figure 2 compares starting material and residues at initial pH 1.2, a different condition from Figure 1; it supports a changed mineral assemblage, not an identical-assay metal balance.
Results 3.2–3.3 retain non-target behavior: dissolved Pb and Au were below the reported 0.1 g/m3 analytical limit, not measured zero. Anglesite peaks appear in the inoculated residue, consistent with secondary Pb precipitation; the detailed dissolution/precipitation route is inferred. Gallium extraction decreases with increasing ore loading and Ga/Au are enriched in residual material, not isolated products. The reported dissolved-Ga concentration in section 3.3 is incompatible with the Table 1 feed inventory at the stated loadings, so that numerical concentration and a closed Ga balance are not accepted.
Figures 4–8 and sections 3.4.1–3.4.5 limit generalization: higher loading lengthens the lag, and section 3.4.3 describes about 80% Cu/Zn extraction at 15 days, whereas the conclusion broadly says above 80% at 10 days across the loading range. Salt addition increases abiotic leaching and suppresses copper bioleaching at higher nominal doses; section 3.4.5 uses kmol/m3 while Figure 8 labels the same NaCl numbers kg/m3, so no resolved salt threshold is asserted. The pH-variation subsection reports smaller drift than section 3.1; no single pH tolerance is imposed on all runs. Replication, chemistry-matched causality and complete mass balance remain unresolved. Figure 9 reuses terrestrial-concentrate results from earlier papers and is not an independent replication of the marine ore assay.
Context_only Source: dsm1651
The issuing collection confirms Acidianus brierleyi DSM 1651 and its terrestrial thermal-spring provenance. It does not certify the adapted culture state, experimental performance or a marine strain identity.

Sources & References

  1. usgs2025: U.S. Geological Survey (2025). U.S. Geological Survey Global Seabed Mineral Resources. Fact Sheet 2025–3017, version 1.1, April 2025, page 2 Table 1 and polymetallic-sulfide photograph. Hydrothermal resource identity; asterisks identify constituent membership of the US 2022 critical-mineral list, not a resource-wide designation. Previously acquired official PDF re-inspected.
    https://pubs.usgs.gov/fs/2025/3017/fs20253017.pdf (accessed 2026-10-11)
  2. saito2015: Saito, Haruki, Nomura and Konishi (2015). Bioleaching of Deep-Sea Hydrothermal Ore Deposits by the Acidophilic and Thermophilic Archaeon Acidianus Brierleyi. Journal of MMIJ 131(12):627–633. DOI 10.2473/journalofmmij.131.627. Published 1 December 2015; released on J-STAGE 1 January 2016. Japanese full primary paper with English captions; Methods 2.1–2.2, Table 1, Results 3.1–3.5 and Figures 1–9.
    https://doi.org/10.2473/journalofmmij.131.627 (accessed 2026-10-11)
  3. dsm1651: DSMZ culture catalogue: Acidianus brierleyi DSM 1651, type strain, from thermal spring drainage in Yellowstone National Park. Confirms the culture accession and organism name reported by Saito et al.; catalogue cultivation conditions are not substituted for the paper protocol.
    https://www.dsmz.de/collection/catalogue/details/culture/DSM-1651 (accessed 2026-10-11)

Curation History

Timestamp Curator Action Summary
2026-10-11T13:11:22.652249+00:00 codex (GPT-6; codex) CREATE Created a distinct natural seafloor sulfide resource and a narrowly scoped, controlled laboratory ore-bioleaching mechanism from full primary evidence; retained source inconsistencies, non-target limits and unresolved causal chemistry.

Record source: data/records/seafloor-massive-sulfides.yaml