Petrochemistry of subvolcanic dike swarms associated with the Golden Revenue Au–Cu and the Stoddart Mo–Cu±W mineralizations (Dawson Range, Yukon Territory, Canada) and implications for ore genesis

Betsi, Thierry Bineli; Lentz, David R.

doi:10.1016/j.oregeorev.2011.01.003

Cited by 14 publications

(5 citation statements)

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“…Thus, the mineralogical characteristics of Bi:(Te+S) inclusions in gold from both Nucleus/Revenue and Sonora Gulch are consistent with a relatively reduced intrusion as described by Allan et al (2013). Betsi and Lentz (2011) presented a paragenesis for the Nucleus deposit which showed a strong Bi-BiS component but not Bi-Te±S minerals reported in the current study. The apparent disparity may be a function of local conditions of mineralization and prevailing fTe as suggested by Tooth et al (2011).…”

Section: Comparison Of Microchemical Signatures Of Gold From Differencontrasting

confidence: 54%

“…The apparent disparity may be a function of local conditions of mineralization and prevailing fTe as suggested by Tooth et al (2011). In conclusion, it seems likely that the reduced nature of the Nucleus/Revenue intrusion (perhaps a consequence of the assimilation of reduced crust, Betsi and Lentz 2011) explains the importance of the bismuth telluride collector model both here and at Sonora Gulch. Figure 3c shows that for all Nucleus-Revenue samples, the host alloy of chalcopyrite and pyrite inclusions exhibit higher Ag values than the gold associated with bismuth-bearing minerals.…”

Section: Comparison Of Microchemical Signatures Of Gold From Differenmentioning

confidence: 66%

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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

et al. 2017

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Porphyry-epithermal and orogenic gold are two of the most important styles of gold-bearing mineralization within orogenic belts. Populations of detrital gold resulting from bulk erosion of such regions may exhibit a compositional continuum wherein Ag, Cu, and Hg in the gold alloy may vary across the full range exhibited by natural gold. This paper describes a new methodology whereby orogenic and porphyry-epithermal gold may be distinguished according to the mineralogy of microscopic inclusions observed within detrital gold particles. A total of 1459 gold grains from hypogene, eluvial, and placer environments around calcalkaline porphyry deposits in Yukon (Nucleus-Revenue, Casino, Sonora Gulch, and Cyprus-Klaza) have been characterized in terms of their alloy compositions (Au, Ag, Cu, and Hg) and their inclusion mineralogy. Despite differences in the evolution of the different magmatic hydrothermal systems, the gold exhibits a clear Bi-Pb-Te-S mineralogy in the inclusion suite, a signature which is either extremely weak or (most commonly) absent in both Yukon orogenic gold and gold from orogenic settings worldwide. Generic systematic compositional changes in ore mineralogy previously identified across the porphyry-epithermal transition have been identified in the corresponding inclusion suites observed in samples from Yukon. However, the Bi-Te association repeatedly observed in gold from the porphyry mineralization persists into the epithermal environment. Ranges of P-T-X conditions are replicated in the geological environments which define generic styles of mineralization. These parameters influence both gold alloy composition and ore mineralogy, of which inclusion suites are a manifestation. Consequently, we propose that this methodology approach can underpin a widely applicable indicator methodology based on detrital gold.

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Section: Comparison Of Microchemical Signatures Of Gold From Differencontrasting

confidence: 54%

Section: Comparison Of Microchemical Signatures Of Gold From Differenmentioning

confidence: 66%

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

et al. 2017

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“…). Both plutons and dikes are mostly of granitic and locally of granodioritic compositions, essentially peraluminous, and were classified as ilmenite and S‐type granitoids (Bineli Betsi & Lentz, , ). Plutonic bodies are mainly composed of: (i) medium‐grained, and equigranular leucogranite; (ii) fine‐grained, foliated and unfoliated, locally porphyritic leucrogranite (microgranite of Sexton et al , ), and; (iii) rare medium‐grained biotite–hornblende granite.…”

Section: Geological Settingmentioning

confidence: 99%

“…Veins within the Nucleus deposit occur as numerous sets (Fig. ) with variable mineralogy, shapes, and textures that cut and are crosscut by intrusions thus suggesting multiple cycles of fluid flux from intrusion(s) (see Bineli Betsi & Lentz, ) and vein emplacements. The dominant vein/veinlet types identified at the Nucleus deposit, as reported in Table , are classified by mineralogy, and structure into the following groups: quartz‐pyrite veinlets, quartz–sulfide veins, quartz–sericite veinlets, molybdenite veins, Au‐bearing veins, Bi‐rich veins, arsenopyrite‐rich veins, and late carbonate veins (see Table ).…”

Section: Types Of Mineralizationmentioning

confidence: 99%

The Nucleus Deposit: Superposed Au–Ag–Bi–Cu Mineralization Systems at Freegold Mountain, Yukon, Canada

2016

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In this paper we present titanite U-Pb (both single crystal CA ID-TIMS and in situ LA ICP-MS) data, coupled with ore and gangue mineralogy and geochemical (both lithogeochemistry and microanalysis) data from the Nucleus Au-Ag-Bi-Cu deposit, in the Yukon (Canada) portion of the Tintina Au province. Arsenic-bearing Au-Ag-Bi-Cu mineralization at Nucleus consists of two distinct styles of mineralization including: (i) reduced Au skarn and sulfide replacement; and (ii) a relatively shallow-emplaced (as supported by textures and temperature of formation), vein-controlled mineralization occurring mainly as veins and veinlets of various shapes (sheeted, single, stockworks, and crustiform), breccias, and disseminations. Whereas Au, Bi, and Cu mineralization from skarn is associated with hydrous retrograde alteration phases (actinolite, ferro-actinolite, hastingsite, cannilloite, and hornblende), numerous alteration types are associated with the vein-controlled style of mineralization and these include: biotite, phyllic, argillic, propylitic, carbonate, and quartz (silicification) alterations. The mineralization-alteration processes took place over a wide temperature range that is bracketed between 340 and 568°C, as indicated by chlorite and arsenopyrite geothermometers. The Au-rich Nucleus deposit is characterized by anomalously high content of As and Bi (as much as 1 %), and whereas Au moderately correlates with Bi (r = 0.40) in the skarn mineralization style (where native Au is spatially associated with native Bi and Bi-bearing sulfides), the two elements correlate poorly (r = 0.14) in the vein-controlled type, in which native Bi-and Bi-sulfide-bearing veins are locally observed. Sphalerite from the vein-controlled mineralized type is Fe-rich (9.92-10.54 mol % FeS) indicative of low sulfidation conditions, as well as high temperature, with the latter further supported by arsenopyrite geothermometry (up to 491°C), low Ag content (3-7 wt.%) in Au, and the high gold fineness (926-964). Whereas molybdenite Re-Os ages from quartz-molybdenite veins range from 75.8 to 76.2 ± 0.3 Ma, titanite from the skarn type mineralization recorded CA ID-TIMS and LA ICP-MS U-Pb ages of 182.6 ± 2.4 Ma and 191.0 ± 1.5 Ma, respectively, thus precluding any genetic link between the two spatially associated styles of mineralization from the Nucleus deposit area. The Au-Ag-Bi-Cu Nucleus deposit is therefore regarded as a superposed system in which two mineralization types, without any petrogenetic relationship, overlapped, possibly with remobilization of early-formed mineralization.Notes: TB 504, TB 398, and TB 309 are from vein-controlled mineralization type, and TB 352 is from sulfide replacement. AV, average; 1σ, standard deviation.Nucleus: superposed mineralized system

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“…Previous studies in the Freegold Mountain area include reconnaissancescale mapping (Tempelman-Kluit 1984;Carlson 1987;Payne et al 1987), geochronology (U-Pb) investigations (Bineli Betsi and Bennett 2010), investigation of the petrogenesis of subvolcanic dykes (McInnes et al 1988;Smuk et al 1997;Bineli Betsi and Lentz 2011), and detailed investigation of mineralized zones, such as (i) Laforma Au deposit and its two adjacent prospects, the Antoniuk Au-bearing breccias and the Emmons Hill polymetallic veins (McInnes et al 1990), (ii) Tinta Hill base-metal-Au-Ag deposit (Morin 1981;Smuk et al 1997), and (iii) nucleus Au-Bi-Cu-As mineralization. However, studies elucidating the thermal history and exhumation rate of different mineralized systems are missing, even though these factors are critical to our understanding of genesis, grade, and the temporal distribution of ore deposits (McInnes et al 2005aKesler and Wilkinson 2006;Uchida et al 2007).…”

Section: Introductionmentioning

confidence: 99%

Emplacement ages and exhumation rates for intrusion-hosted Cu–Mo–Sb–Au mineral systems at Freegold Mountain (Yukon, Canada): assessment from U–Pb, Ar–Ar, and (U–Th)/He geochronometers

et al. 2012

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To decipher the thermal history of mineralized systems across the Freegold Mountain area (Yukon, Canada), a combined geochronology (zircon U-Pb and hornblende, biotite, and whole rock Ar-Ar) and thermochronology (apatite and zircon (U-Th)/He) study was carried out. Previous U-Pb data combined with new U-Pb and Ar-Ar data show that intrusive bodies across the Freegold Mountain were emplaced during two protracted episodes, the first spanning from 109.6 to 98 Ma and the second between 79 and 68 Ma. Overprinting of the first intrusive event by a second magmatic hydrothermal event is suggested by a zircon U-Pb age of 108.7 ± 0.4 Ma for a chlorite-altered dyke and a whole rock Ar-Ar plateau age of 76.25 ± 0.53 Ma. Zircon (U-Th)/He data are between 66 and 89 Ma, whereas apatite (U-Th)/He data are scattered (38.7-109.9 Ma) and bracket the two magmatic emplacement events. Our combined data reveal a complex history of reheating that led to resetting of numerous chronometers. In most of the investigated magmatic hydrothermal systems, early fast cooling from igneous emplacement through hydrothermal alteration (between 900 and 200°C) was followed by later and slower cooling accompanying post mineralization uplift and erosion (between 200 and 70°C). Preliminary models indicate intrusive bodies associated with the Stoddart Cu-Mo ± W prospect cooled slowly (23°C/Ma) compared with the ones spatially associated with the Revenue Au-Cu prospect (43°C/Ma), and the similarity of the zircon U-Pb and (U-Th)/He ages from Revenue dyke further supports a rapid cooling from 700 to 180°C. Erosion rates of 0.035-0.045 mm/year are consistent with tectonic quiescence during the Late Tertiary combined with the lack of Pleistocene glaciation in central Yukon. Such low rates of exhumation favour the formation and preservation of supergene mineralization, such as that found north of Freegold Mountain. Résumé : Afin de pouvoir décoder l'historique thermique des systèmes minéralisés à travers le secteur du mont Freegold (Yukon, Canada), une étude combinée de géochronologie (U-Pb sur zircon et Ar-Ar sur hornblende, biotite et la roche entière) et de thermochronologie (apatite et zircon (U-Th)/He) a été entreprise. Les données antérieures U-Pb, combinées aux nouvelles données U-Pb et Ar-Ar montrent que des amas intrusifs ont été mis en place au mont Freegold au cours de deux épisodes prolongés, le premier de 109,6 à 98 Ma et l'autre entre 79 et 68 Ma. Une surimpression du premier événement intrusif par un autre événement magmatique hydrothermal est suggérée par une datation U-Pb sur zircon, de 108,7 ± 0,4 Ma, pour un dyke altéré par de la chlorite; aussi, un âge plateau Ar-Ar, pour la roche entière, donne 76,25 ± 0,53 Ma. Des données (U-Th)/He pour le zircon varient entre 66 et 89 Ma alors que des données (U-Th)/He pour l'apatite sont plus dispersées (entre 38,7 et 109,9 Ma) et encadrent les deux événements magmatiques de mise en place. Nos données combinées révèlent un historique complexe de réchauffements qui ont conduit au rajustement de nombreux ch...

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Petrochemistry of subvolcanic dike swarms associated with the Golden Revenue Au–Cu and the Stoddart Mo–Cu±W mineralizations (Dawson Range, Yukon Territory, Canada) and implications for ore genesis

Cited by 14 publications

References 50 publications

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

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

The Nucleus Deposit: Superposed Au–Ag–Bi–Cu Mineralization Systems at Freegold Mountain, Yukon, Canada

Emplacement ages and exhumation rates for intrusion-hosted Cu–Mo–Sb–Au mineral systems at Freegold Mountain (Yukon, Canada): assessment from U–Pb, Ar–Ar, and (U–Th)/He geochronometers

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