Fluid geochemistry of the Serra Pelada Au-Pd-Pt deposit, Carajás, Brazil: Exceptional metal enrichment caused by deep reaching hydrothermal oxidation

Berni, Gabriel V.; Heinrich, Christoph A.; Wälle, Marküs; Wall, V. J.

doi:10.1016/j.oregeorev.2019.102991

Cited by 7 publications

(2 citation statements)

References 27 publications

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“…The fluids contained chlorides Na > K > Ca ≥ Mg. The trapping temperature and salinity of fluid inclusions without and containing gold (50-500 ppb) in hematite are 155-185 °С and 4-6.5 wt.%, and 165-175 °С and 4.5-6 wt.%, respectively [144].…”

Section: Physicochemical Conditions For the Formation Of Palladian Go...mentioning

confidence: 98%

Palladian Gold: Chemical Composition, Minerals in Association, and Physicochemical Conditions of Formation at Different Types of Gold Deposits

Palyanova,

Zhegunov,

Beliaeva

et al. 2023

Minerals

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This paper reviews and summarizes the available information on the composition of palladian gold with various contents and sets of isomorphic impurities (Ag, Cu, Hg) at 50 deposits and ore occurrences with Au-Pd mineralization. It is revealed that Palladian gold is represented by the systems Au–Pd, Au–Pd–Hg, Au–Pd–Cu, and Au–Pd–Ag–Hg, but more frequently corresponds to Au–Pd–Ag, Au–Pd–Ag–Cu, and Au–Pd–Ag–Cu–Hg. Objects with palladian gold belong to different types of gold deposits and to the deposits at which the main components of ores are PGE, Cr, Cu, Ni, V, and Ti. We propose a classification of the types of deposits with palladian gold: (1) PGE ore deposits related to mafic–ultramafic magmatic complexes (two subtypes—(a) low-sulfide-grade (less than 2%–5% sulfides) Alaskan, and (b) high-sulfide-grade (more than 5% sulfides) Norilsk); (2) orogenic gold deposits (OG); (3) epithermal (porphyry) gold–copper deposits (EPGC); (4) iron oxide copper gold deposits (IOCG); (5) ferruginous quartzite deposits; (6) volcanic exhalation; and (7) gold-PGE placers of five subtypes corresponding to the types of 1–5 primary sources. Palladian gold is mainly high-fineness (910‰–990‰), is less frequently medium-fineness, and contains Ag and Cu, but does not contain Hg at the deposits of types 1, 3, and 4. The only exception is the Au-Pd-Hg Itchayvayam ore occurrence (Kamchatka, Russia), for which two varieties of Pd,Hg-bearing native gold (fineness 816‰–960‰ and 580‰–660‰) are determined. Low-fineness palladian gold with the major content of Ag is typical of OGD deposits. Medium-fineness palladian gold occurs at ferruginous quartzite deposits and in volcanic exhalations. Hg, Ag, Cu-bearing high-fineness palladian gold is present mainly in placer deposits (type 7). The most common minerals in association with palladian gold are arsenides, stibioarsenides, sulfides, stannides, bismuthides, tellurides, and selenides of Pd and Pt. These are typical of deposit types 1 and 7. The minerals of Au, Ag, and Cu (tetra-auricupride, aurostibite, chalcopyrite, bornite, chalcocite, eucairite, etc.) are in association with palladian gold at OG, EPGC, and IOCG deposits. Hg minerals (cinnabar, tiemannite, coloradoite, potarite) are at some deposits (types 1, 2, 7-1, 7-4). Cu, Fe, and Pd oxides (tenorite, hematite, magnetite, PdO, (Pd,Cu)O) and Fe and Pd hydroxides (goethite, (Fe,Pd)OOH) occur at the deposits of the 3, 4, and 7 groups and indicate the highly oxidizing conditions of ore formation. The most common minerals among host minerals are quartz and muscovite, including fuchsite (Cr-Ms), chlorite, albite, K-feldspar, hornblende, and carbonates (calcite, siderite, etc.). The fineness, content, and set of impurities in palladian gold and minerals in association with it reflect the mineralogy of Au-Pd ores and allow them to be used as indicators for the deposit types.

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Section: Physicochemical Conditions For the Formation Of Palladian Go...mentioning

confidence: 98%

Palladian Gold: Chemical Composition, Minerals in Association, and Physicochemical Conditions of Formation at Different Types of Gold Deposits

Palyanova,

Zhegunov,

Beliaeva

et al. 2023

Minerals

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“…The fluids forming Au-Pd mineralization at the Chudnoe deposit are similar in salt composition to the ore-forming fluids of hydrothermal Au-Ag deposits, though the latter are characterized by higher formation temperatures, higher salinity of fluids and frequent presence of dense gases (CO 2 , N 2 , CH 4 ) in the composition of fluids [58]. They are similar in temperature, concentration, and composition of salts (Ca-Na-K chlorides, carbonates, and hydrocarbonates) to the ore-forming fluids of Au-Pd deposits (Serra Pelada, Bleida Far West), for which an infiltration model of formation with participation of oxidized basin Na-Ca chloride waters is assumed [59][60][61]. However, these deposits are characterized by the presence of Se-bearing PGM (Pd-Pt-Se, Pd-Se, Pd-Hg-Se, and Pd-Bi-Se phases, and sudovikovite and palladseite) [62].…”

Section: Inferences On the Ptx Parameters Of Au-pd-ree Mineralizationmentioning

confidence: 99%

Native Gold in the Chudnoe Au-Pd-REE Deposit (Subpolar Urals, Russia): Composition, Minerals in Intergrowth and Genesis

et al. 2021

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Composition of native gold and minerals in intergrowth of the Chudnoe Au-Pd-REE deposit (Subpolar Urals, Russia) was studied using optical microscopy, scanning electron microscopy, and electron microprobe analysis. Five varieties of native gold have been identified, based on the set of impurity elements and their quantities, and on intergrown minerals. Native gold in rhyolites from the Ludnaya ore zone is homogeneous and contains only Ag (fineness 720‰, type I). It is in intergrowth with fuchsite or allanite and mertieite-II. In rhyolites from the Slavnaya ore zone, native gold is heterogeneous, has a higher fineness, different sets and contents of elements: Ag, Cu, 840–860‰ (type II); Ag, Cu, Pd, 830–890‰ (III); Ag, Pd, Cu, Hg, 840–870‰ (IV). It occurs in intergrowth with fuchsite, albite, and mertieite-II (type II), or albite, quartz, and atheneite (III), or quartz, albite, K-feldspar, and mertieite-II (IV). High-fineness gold (930–1000‰, type V) with low contents of Ag, Cu, and Pd or their absence occurs in the form as microveins, fringes and microinclusions in native gold II–IV. Tetra-auricupride (AuCu) is presented as isometric inclusions in native gold II and platelets in the decay structures in native gold III and IV. The preliminary data of a fluid inclusions study showed that gold mineralization at the Chudnoe deposit could have been formed by chloride fluids of low and medium salinity at temperatures from 105 to 230 °C and pressures from 5 to 115 MPa. The formation of native gold I is probably related to fuchsitization and allanitization of rhyolites. The formation of native gold II-V is also associated with the same processes, but it is more complicated and occurred later with a significant role of Na-, Si-, and K-metasomatism. The presence of Pd and Cu in the ores and Cr in fuchsite indicates the important role of mafic-ultramafic magmatism.

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Green tech soil analysis: a comparison of potentially toxic element contents among urban, agricultural, and gold mining areas in the Eastern Brazilian Amazon

Maciel,

Ribeiro,

Pavão

et al. 2024

Environ Geochem Health

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Fluid geochemistry of the Serra Pelada Au-Pd-Pt deposit, Carajás, Brazil: Exceptional metal enrichment caused by deep reaching hydrothermal oxidation

Cited by 7 publications

References 27 publications

Palladian Gold: Chemical Composition, Minerals in Association, and Physicochemical Conditions of Formation at Different Types of Gold Deposits

Palladian Gold: Chemical Composition, Minerals in Association, and Physicochemical Conditions of Formation at Different Types of Gold Deposits

Native Gold in the Chudnoe Au-Pd-REE Deposit (Subpolar Urals, Russia): Composition, Minerals in Intergrowth and Genesis

Green tech soil analysis: a comparison of potentially toxic element contents among urban, agricultural, and gold mining areas in the Eastern Brazilian Amazon

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