New constraints on the origin of the Skaergaard intrusion Cu–Pd–Au mineralization: Insights from high-resolution X-ray computed tomography

Godel, Bélinda; Rudashevsky, N. S.; Nielsen, Thorkild; Barnes, Stephen J.; Rudashevsky, V. N.

doi:10.1016/j.lithos.2013.11.019

Cited by 34 publications

(58 citation statements)

References 38 publications

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“…1d) which marks the base of the mineralized unit. The gabbros of the Triple Group are made up of Fe-rich plagioclase, clinopyroxene and ilmenite/titanomagnetite (Wager and Brown 1968;Bird et al 1991;Andersen et al 1998;Tegner and Cawthorn 2010;Holness et al 2011;Godel et al 2014).…”

Section: Geological Setting Of the Platinova Reef Skaergaard Intrusionmentioning

confidence: 99%

“…Sulfide mineralization is present as tiny (<100 µm) grains of bornite-digenite/chalcocite intergrowths with associated precious metal-bearing minerals, which are dominantly Pd-Pt-Au-Cu-Fe alloys (Bird et al 1991;Andersen et al 1998;Rudashevsky et al 2004;Cabri et al 2005;Nielsen et al 2005;McDonald et al 2009;Godel et al 2014;Rudashevsky et al 2014Rudashevsky et al , 2015Nielsen et al 2015). Figure 1d shows the typical geochemical variations and offsets of base and precious metals through a generalized section of the Triple Group.…”

Section: Geological Setting Of the Platinova Reef Skaergaard Intrusionmentioning

confidence: 99%

“…The Skaergaard Intrusion in east Greenland is host to the Platinova Reef, which is an example of a rare subclass of magmatic sulfide deposit, manifested as stratiform PGE reef deposits in the upper parts of the host intrusions (Brooks 1989;Bird et al 1991;Andersen et al 1998;Nielsen et al 2005, Miller andAndersen 2002;Godel et al 2014;Holwell and Keays 2014;Nielsen et al 2015). These deposits differ from the more common disseminated and massive pyrrhotite-pentlandite-chalcopyrite ores found in the lower parts of layered mafic and ultramafic host intrusions, including along the margins and within conduits that feed larger intrusions (e.g., Maier 2005; Naldrett 2011 and references therein).…”

Section: Introductionmentioning

confidence: 99%

“…However, the metal tenors of the sulfides themselves can be very high. The Platinova Reef itself contains some of the highest Pd tenors of any magmatic sulfide deposit (average of ~1 wt% Pd; Holwell and Keays (2014); and up to 60 wt%; Godel et al 2014). As such the Platinova Reef may represent an end member of this style of mineralization.…”

Section: Introductionmentioning

confidence: 99%

“…As such the Platinova Reef may represent an end member of this style of mineralization. While there are a number of common characteristics to all of these deposits, in detail, there are a great number of geochemical, mineralogical and stratigraphic variations and there is no current consensus on the magmatic and hydrothermal processes operating to explain all of these (e.g., Prendergast 2000;Andersen 2006;Nielsen and Bernstein 2009;Nielsen 2013;Holwell and Keays 2014;Godel et al 2014;Nielsen et al 2015;Keays and Tegner 2015).…”

Section: Introductionmentioning

confidence: 99%

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Extreme enrichment of Se, Te, PGE and Au in Cu sulfide microdroplets: evidence from LA-ICP-MS analysis of sulfides in the Skaergaard Intrusion, east Greenland

Holwell

Keays

McDonald

et al. 2015

Contrib Mineral Petrol

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evidence implies that there is no significant post-magmatic hydrothermal S loss and that the metal profiles are essentially a function of magmatic processes. We propose that to generate these extreme precious and semimetal contents, the sulfides must have formed from an anomalously metal-rich package of magma, possibly formed via the dissolution of a previously PGE-enriched sulfide. Other processes such as kinetic diffusion may have also occurred alongside this to produce the ultra-high tenors. The characteristic metal offset pattern observed is largely controlled by partitioning effects, producing offset peaks in the order Pt+Pd>Au>Te>Se>Cu that are entirely consistent with published D values. This study confirms that extreme enrichment in sulfide droplets can occur in closed-system layered intrusions in situ, but this will characteristically form ore deposits that are so low in sulfide that they do not conform to conventional deposit models for Cu-Ni-PGE sulfides which require very high R factors, and settling of sulfide liquids.

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Section: Geological Setting Of the Platinova Reef Skaergaard Intrusionmentioning

confidence: 99%

Section: Geological Setting Of the Platinova Reef Skaergaard Intrusionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Extreme enrichment of Se, Te, PGE and Au in Cu sulfide microdroplets: evidence from LA-ICP-MS analysis of sulfides in the Skaergaard Intrusion, east Greenland

Holwell

Keays

McDonald

et al. 2015

Contrib Mineral Petrol

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Geochronology of Layered Intrusions

Scoates

Wall

2015

Springer Geology

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Layered intrusions crystallize mainly from basaltic magma to form large bodies of igneous rocks that exhibit prominent layering and they preserve stunning rock records of the processes by which magma evolves in crustal magma chambers. These intrusions contain world-class deposits of chromium, platinum group elements (PGE), and vanadium, metals that are vital to industry and society in general. Despite their scientific and practical importance, precise age constraints are lacking for many layered intrusions, and geochronological frameworks linking crystallization and cooling ages for the most part do not exist. This has resulted in critical knowledge gaps related to their origin and formation. This chapter provides an overview of dating methods (U-Th-Pb, 40 Ar/ 39 Ar) and mineral chronometers (e.g., zircon, baddeleyite, rutile, apatite, titanite) potentially present in layered intrusions that is coupled with field, textural, and petrographic criteria for targeting sample selection to allow for the successful implementation of geochronologic studies of layered mafic-ultramafic rocks of any age. As an application, we demonstrate how the thermal history of the Bushveld Complex is documented by mineral ages from samples of the PGE-rich Merensky Reef. High-precision U-Pb zircon ages, involving pretreatment of zircon by the chemical abrasion (annealing and leaching) or CA-TIMS technique, for two samples separated by > 300 km are indistinguishable from each other (2056.88 ± 0.41 Ma, Eastern Limb; 2057.04 ± 0.55 Ma, Western Limb; uncertainty reported as 2s) confirming synchronous crystallization of this horizon at near-solidus conditions across the intrusion. Rapid cooling (~ 125 °C/Ma) down to temperatures of ~ 400-450 °C is defined by U-Pb rutile ages from the same samples (2052( .96 ± 0.61 Ma, 2053.0 ± 2.7 Ma) and a regional hydrothermal event is signaled in 40 Ar/ 39 Ar biotite ages (1999 ± 10 Ma, 2002 ± 10 Ma). The geochronology of layered intrusions, where magma differentiation processes are captured in a wide range of rock textures and structures, represents an essential tool for assessing the evolution of mafic magmatism in the Earth's crust.

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New constraints on the origin of the Skaergaard intrusion Cu–Pd–Au mineralization: Insights from high-resolution X-ray computed tomography

Cited by 34 publications

References 38 publications

Extreme enrichment of Se, Te, PGE and Au in Cu sulfide microdroplets: evidence from LA-ICP-MS analysis of sulfides in the Skaergaard Intrusion, east Greenland

Extreme enrichment of Se, Te, PGE and Au in Cu sulfide microdroplets: evidence from LA-ICP-MS analysis of sulfides in the Skaergaard Intrusion, east Greenland

Geochronology of Layered Intrusions

Platinum-Group Element Deposits in Layered Intrusions: Recent Advances in the Understanding of the Ore Forming Processes

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