Rhenium in Molybdenite: a Database Approach to Identifying Geochemical Controls on the Distribution of a Critical Element

Geology and geochronology of the Two-Thirty prospect, Northparkes district, NSW

“…Although the ages of the molybdenites from Northparkes and Two-Thirty are identical, their contrasting Re contents (i.e., 1264-1717 ppm Northparkes vs 225 ppm for Two-Thirty; Table 7) suggests significant differences in magmatic-hydrothermal evolution or depositional conditions at the two sites. The high Re contents at Northparkes are similar to those of other alkalic-hosted porphyry deposits in the region such as Cadia (Kemp et al, 2020;e.g., Wilson et al, 2007) and Cu ± Au porphyry deposits generally (Barton et al, 2020;Berzina et al, 2005;Stein, 2014;Stein et al, 2001;Terada et al, 1971) . These high-Re molybdenites are strongly associated with intermediate-composition intrusions and have been ascribed to a significant mantle contribution to the magmas (Barton et al, 2020;Berzina et al, 2005;e.g., Stein et al, 2001).…”

“…The high Re contents at Northparkes are similar to those of other alkalic-hosted porphyry deposits in the region such as Cadia (Kemp et al, 2020;e.g., Wilson et al, 2007) and Cu ± Au porphyry deposits generally (Barton et al, 2020;Berzina et al, 2005;Stein, 2014;Stein et al, 2001;Terada et al, 1971) . These high-Re molybdenites are strongly associated with intermediate-composition intrusions and have been ascribed to a significant mantle contribution to the magmas (Barton et al, 2020;Berzina et al, 2005;e.g., Stein et al, 2001).…”

“…In contrast, lower Re concentrations in molybdenite are typically associated with more evolved magmatic-hydrothermal systems, although physicochemical conditions such as redox and the availability of reduced sulfur also exerts a strong control on molybdenite Re contents (Barton et al, 2020). Therefore, the lower Re content of the Two-Thirty molybdenite relative to Ordovician porphyry mineralisation elsewhere in the Macquarie Arc may be indicating a difference in magmatic sources, which could be tested through additional radiogenic isotope studies (e.g., Rb-Sr, Sm-Nd, Lu-Hf).…”

3R-MoS2 in Review: History, Status, and Outlook

“…Finally, 3R-MoS 2 may be obtained by extraction from molybdenite ore. An exhaustive list of globally reported instances of 3R-MoS 2 samples is too large for this review (>1000 at the time of writing); instead, a selection of metastudies are provided (also see ref for suggested search terms). ,,− Natural occurrence of the 3R-MoS 2 polytype has been shown to strongly correlate to the presence and concentration of impurities; primarily rhenium, but also tungsten, niobium, vanadium, iron, and titanium . It appears that these impurities induce defects in nascent MoS 2 , which make 3R-MoS 2 growth by screw dislocation more probable (vide supra). , Given that rhenium is both valuable and scarce (with an average crustal abundance of 0.5 ppb), and that MoS 2 is the primary deposit in which rhenium is found (it can substitute up to tens of percent of Mo atoms), the 3R-MoS 2 fraction of natural molydenite is an important indicator of the value of the molybdenite ore. Additionally, because 187 Re will undergo β decay to produce 187 Os, the Re/Os ratio may be used as a chronometer, which makes 3R-MoS 2 deposits important for dating strata. , The 3R-MoS 2 fraction of molybdenite also has implications for the processing and recovery of the ore. McClung showed that the 3R-MoS 2 polytype is more difficult to grind and is harder to separate by flotation as it less buoyant than is the 2H-MoS 2 phase…”

“…Finally, 3R-MoS 2 may be obtained by extraction from molybdenite ore. An exhaustive list of globally reported instances of 3R-MoS 2 samples is too large for this review (>1000 at the time of writing); instead, a selection of metastudies are provided (also see ref 111 for suggested search terms). 20,44,108−111 Natural occurrence of the 3R-MoS 2 polytype has been shown to strongly correlate to the presence and concentration of impurities; 110 primarily rhenium, but also tungsten, niobium, vanadium, iron, and titanium. 112 It appears that these impurities induce defects in nascent MoS 2 , which make 3R-MoS 2 growth by screw dislocation more probable (vide supra).…”