A new indicator mineral methodology based on a generic Bi-Pb-Te-S mineral inclusion signature in detrital gold from porphyry and low/intermediate sulfidation epithermal environments in Yukon Territory, Canada

Chapman, Robert J.; Allan, Murray M.; Mortensen, James K.; Wrighton, Timothy; Grimshaw, Matthew Russel

doi:10.1007/s00126-017-0782-0

Cited by 37 publications

(38 citation statements)

References 41 publications

(64 reference statements)

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“…informative. Spider diagrams, which depict the relative abundance of different minerals alleviate this issue but quickly become difficult to interpret when more than 3 or 4 assemblages are superimposed on the same diagram (Chapman et al 2017b). In the present study, inclusions were extremely scarce, but nevertheless, mineral speciation provides an informative avenue of study.…”

Section: Methodsmentioning

confidence: 83%

“…9 shows the general inverse relationship between Ag and Cu for the whole population of gold grains. This feature appears to be generic (Moles et al 2013, Chapman et al, 2017b) and it appears that the Cu content is largely controlled by the Ag content of the Au alloy. Thus, in the majority of cases, Cu in Au-Ag alloy may not be a useful discriminator.…”

Section: Copper (Cu)mentioning

confidence: 92%

“…Majority of the gold grains contain Cu, which can be used with Au alloy in conjunction with the associated Ag to identify discrete compositional fields (Chapman et al 2017b). Fig.…”

Section: Copper (Cu)mentioning

confidence: 99%

“…Subsequent detailed studies of gold from other Phanerozoic orogenic gold areas in the Canadian Cordillera have reinforced this compositional template, (Chapman et al 2010a(Chapman et al ,b, 2016. Gold from magmatic hydrothermal system has proved to be compositionally distinct, as calc alkaline porphyries and associated epithermal systems in Yukon showed a generic Bi-Pb-Te-S association in the inclusion assemblage (Chapman et al 2017b) whereas gold from alkalic porphyry systemsin British Columbia were identifiable through their Hg-Pd inclusionsignature (Chapman et al 2017a).…”

Section: Comparison Of Gold Signature With Those Associated With Othementioning

confidence: 99%

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Microchemical characterization of placer gold grains from the Meyos-Essabikoula area, Ntem complex, southern Cameroon

Dongmo

Chapman

Bolarinwa

et al. 2019

Journal of African Earth Sciences

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Gold occurs as a native metal, usually containing silver, and in some cases mercury, copper, and palladium. It may also occur as inclusions within sulfur-rich minerals, such as pyrite and arsenopyrite. The style and variety of gold mineralization is influenced by the geological setting, chemistry of the ore fluids, and the nature of their interactions with rocks. Gold grains liberated from bedrock into surficial sediments during weathering and erosion are chemically stable and may be characterized according to their mineralogy: i.e the alloy composition and suite of mineral inclusions revealed within polished sections, characteristics faithful to gold from the hypogene source. This approach has been applied to placer gold grains from the Meyos-Essabikoula area, Cameroon, where the source of gold is not yet confirmed due to poor outcrop exposure. A total of 221 alluvial gold grains from 10 sites, tributaries of Sing and Bivele River over the Ntem Complex have been studied using Electron Probe Micro-Analysis (EMPA) to determine the concentration of minor alloying metals, (notably Au, Ag, Cu, and Hg) and Scanning Electron Microscopy (SEM) in order to evaluate the assemblage of mineral inclusions within the gold. Most of the grains are sub-rounded with pitted surfaces and inclusions of pyrrhotite, acanthite, and chalcopyrite were observed. The grains are Au-Ag alloys ranging from 54.4-99.8 wt% Au, 0.1-48.4 wt% Ag, 0.1-0.8 wt% Hg and 0-0.3 wt% Cu. The presence of Fe oxide (magnetite) inclusions containing Cr and V (to around 5 wt %) has not been reported elsewhere and suggests a strong interaction between hot reducing ore fluids and local mafic lithologies.

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Section: Methodsmentioning

confidence: 83%

Section: Copper (Cu)mentioning

confidence: 92%

“…Majority of the gold grains contain Cu, which can be used with Au alloy in conjunction with the associated Ag to identify discrete compositional fields (Chapman et al 2017b). Fig.…”

Section: Copper (Cu)mentioning

confidence: 99%

Section: Comparison Of Gold Signature With Those Associated With Othementioning

confidence: 99%

See 2 more Smart Citations

Microchemical characterization of placer gold grains from the Meyos-Essabikoula area, Ntem complex, southern Cameroon

Dongmo

Chapman

Bolarinwa

et al. 2019

Journal of African Earth Sciences

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“…However, there are limitations to the adoption of gold grain studies. Firstly the technique is specific to gold, although Chapman et al (2017Chapman et al ( , 2018 have advocated the use of detrital gold as a pathfinder for copper porphyry mineralization. Secondly, substantial field time may be required to collect sufficient detrital particles for study, particularly in areas where overall abundance is low.…”

Section: Evaluation Of the Strengths And Weaknesses Of Each Methods Anmentioning

confidence: 99%

Integration of Detrital Gold Microchemistry, Heavy Mineral Distribution, and Sediment Geochemistry to Clarify Regional Metallogeny in Glaciated Terrains: Application in the Caledonides of Southeast Ireland

Moles

Chapman

2019

Economic Geology

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including the URL of the record and the reason for the withdrawal request. Economic Geology Integration of detrital gold microchemistry, heavy mineral distribution and sediment geochemistry to clarify regional metallogeny in glaciated terrains: application in the Caledonides of southeast Ireland-Manuscript Draft-Manuscript Number: SEG-D-18-00134R2 Full Title: Integration of detrital gold microchemistry, heavy mineral distribution and sediment geochemistry to clarify regional metallogeny in glaciated terrains: application in the Caledonides of southeast Ireland Article Type: Regular Paper

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Chemical and physical heterogeneity within native gold: implications for the design of gold particle studies

et al. 2021

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Studies of populations of gold particles are becoming increasingly common; however, interpretation of compositional data may not be straightforward. Natural gold is rarely homogenous. Alloy heterogeneity is present as microfabrics formed either during primary mineralization or by modification of pre-existing alloys by chemical and physical drivers during subsequent residence in either hypogene or surficial environments. In electron-probe-microanalysis (EPMA)-based studies, the combination of Cu, Hg, and Pd values and mineral inclusion suites may be diagnostic for source style of mineralization, but Ag alone is rarely sufficient. Gold characterization studies by laser-ablation-ICP mass spectrometry linked to both quadrupole and Time-of-Flight (ToF-MS) systems show that only Ag, Cu, and Hg form homogenous alloys with Au sufficiently often to act as generic discriminants. Where present, other elements are commonly distributed highly heterogeneously at the micron or submicron scale, either as mineral inclusions or in highly localized, but low concentrations. Drawing upon our own data derived from individual inspection and analyses of approximately 40,000 gold particles from 526 placer and in situ localities worldwide, we show that adequate characterization of gold from a specific locality normally requires study of a minimum of 150 particles via a two-stage approach comprising spatial characterization of compositional heterogeneity, plus crystallographic orientation mapping, that informs subsequent targeted acquisition of quantitative compositional data by EPMA and/or laser-ablation ICP-MS methods. Such data provide the platform to review current understanding of the genesis of gold particle characteristics, elevating future compositional studies from empirical descriptions to process-focused interpretations.

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A new indicator mineral methodology based on a generic Bi-Pb-Te-S mineral inclusion signature in detrital gold from porphyry and low/intermediate sulfidation epithermal environments in Yukon Territory, Canada

Cited by 37 publications

References 41 publications

Microchemical characterization of placer gold grains from the Meyos-Essabikoula area, Ntem complex, southern Cameroon

Microchemical characterization of placer gold grains from the Meyos-Essabikoula area, Ntem complex, southern Cameroon

Integration of Detrital Gold Microchemistry, Heavy Mineral Distribution, and Sediment Geochemistry to Clarify Regional Metallogeny in Glaciated Terrains: Application in the Caledonides of Southeast Ireland

Chemical and physical heterogeneity within native gold: implications for the design of gold particle studies

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