An essential role for sulfur in sulfide-silicate melt partitioning of gold and magmatic gold transport at subduction settings

Li, Yuan; Feng, Liang; Kiseeva, Ekaterina S.; Gao, Zenghao; Guo, Haihao; Du, Zhuofei; Wang, Fangyue; Shi, Lanlan

doi:10.1016/j.epsl.2019.115850

Cited by 40 publications

(29 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous studies suggest that gold crystallizes from silicate melt as native element or intermetallic compound (typically with copper and silver) [14][15][16][17]39,47,48,99], or as a minor component in base metal sulfides [100][101][102][103]. In subduction-related environments, gold is preferentially partitioned into sulfide (monosulfide solid solution, or MSS) phase, especially under oxidized and sulfur-rich conditions [28,31,32,[49][50][51][52][53][54][55][56]58]. Other factors contributing to either gold concentration or fractionation in magmatic environment include pressure and salinity of melts and associated fluids [104][105][106][107].…”

Section: Formation Of Au-bearing Compounds In Mineralized Volcanic Systemsmentioning

confidence: 99%

“…The behavior of gold (as well as copper and silver) during magmatic differentiation of silicate magmas appears to be strongly controlled by sulfur content of these magmas [51][52][53]58,102]. In S-poor melts, gold is either preferentially sequestered (most probably as micro-and nano-nuggets [114,115]) along with platinum-group metals into fractionating silicate liquids or the early-stage crystalline mush below the top of convective, differentiating magma chamber [116].…”

Section: Formation Of Au-bearing Compounds In Mineralized Volcanic Systemsmentioning

confidence: 99%

“…Another way of forming gold-bearing alloys is through the desulphurization of primary magmatic sulfides enriched in noble and chalcophile metals. Noble metals are partitioned into base metal sulfides that crystallize from sulfide-rich silicate melts under wide range of pressures, temperatures, and sulfur and oxygen fugacity values [49][50][51][52][53][54][55]58,[99][100][101][102][103]. Gold, in particular, exhibits chalcophile behavior during partial melting and magmatic crystallization and is strongly affected by presence or absence of sulfide phases during these processes [16,[30][31][32][33][51][52][53].…”

Section: Formation Of Au-bearing Compounds In Mineralized Volcanic Systemsmentioning

confidence: 99%

“…The presence of native gold in ultramafic rocks [28][29][30] along with bulk-rock gold enrichments in some mantle peridotites [31][32][33][34] and crustal plutonic complexes [35][36][37], indicate that gold is transported from lithospheric mantle sources through magmatic plumbing conduits and finally concentrated at economic levels in epithermal environment [16,19,[38][39][40][41][42][43][44]. Although gold appears to behave as an incompatible element during magmatic differentiation under certain conditions [45][46][47][48], its geochemical behavior is strongly controlled by sulfur and oxygen fugacity in most magmatic-hydrothermal systems [49][50][51][52][53]. In general, gold is scavenged into sulfides in sulfur-rich, mafic to intermediate magmas [54][55][56][57][58] and is deposited as native metal or intermetallic compound in presence of reduced fluids [14,15,17,38,39,47].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Gold in Mineralized Volcanic Systems from the Lesser Khingan Range (Russian Far East): Textural Types, Composition and Possible Origins

et al. 2021

View full text Add to dashboard Cite

While gold partitioning into hydrothermal fluids responsible for the formation of porphyry and epithermal deposits is currently well understood, its behavior during the differentiation of metal-rich silicate melts is still subject of an intense scientific debate. Typically, gold is scavenged into sulfides during crustal fractionation of sulfur-rich mafic to intermediate magmas and development of native forms and alloys of this important precious metal in igneous rocks and associated ores are still poorly documented. We present new data on gold (Cu-Ag-Au, Ni-Cu-Zn-Ag-Au, Ti-Cu-Ag-Au, Ag-Au) alloys from iron oxide deposits in the Lesser Khingan Range (LKR) of the Russian Far East. Gold alloy particles are from 10 to 100 µm in size and irregular to spherical in shape. Gold spherules were formed through silicate-metal liquid immiscibility and then injected into fissures surrounding the ascending melt column, or emplaced through a volcanic eruption. Presence of globular (occasionally with meniscus-like textures) Cu-O micro-inclusions in Cu-Ag-Au spherules confirms their crystallization from a metal melt via extremely fast cooling. Irregularly shaped Cu-Ag-Au particles were formed through hydrothermal alteration of gold-bearing volcanic rocks and ores. Association of primarily liquid Cu-Ag-Au spherules with iron-oxide mineralization in the LKR indicates possible involvement of silicate-metallic immiscibility and explosive volcanism in the formation of the Andean-type iron oxide gold-copper (IOCG) and related copper-gold porphyry deposits in the deeper parts of sub-volcanic epithermal systems. Thus, formation of gold alloys in deep roots of arc volcanoes may serve as a precursor and an exploration guide for high-grade epithermal gold mineralization at shallow structural levels of hydrothermal-volcanic environments in subduction zones.

show abstract

Section: Formation Of Au-bearing Compounds In Mineralized Volcanic Systemsmentioning

confidence: 99%

Section: Formation Of Au-bearing Compounds In Mineralized Volcanic Systemsmentioning

confidence: 99%

Section: Formation Of Au-bearing Compounds In Mineralized Volcanic Systemsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Gold in Mineralized Volcanic Systems from the Lesser Khingan Range (Russian Far East): Textural Types, Composition and Possible Origins

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Luhr, 1990;Carroll & Webster, 1994;Scaillet et al, 1998), and consequently silicate melts were usually considered not to be an efficient agent of sulphur extraction from the slab. However, experimental works have demonstrated that the sulphur content of high pressure oxidized hydrous silicic melts is at least 10-20 times higher than at low pressures (Prouteau & Scaillet, 2013;Jégo & Dasgupta, 2014;Canil & Fellows, 2017;D'Souza & Canil, 2018;Li et al, 2019). This finding reduces the restriction that the sulphur-rich character of present-day arc volcanism bears evidence solely of a sulphur-rich hydrous fluid.…”

Section: Introductionmentioning

confidence: 97%

The Role of Sulphur on the Melting of Ca-Poor Sediment and on Trace Element Transfer in Subduction Zones: An Experimental Investigation

Pelleter

Prouteau

Scaillet

2021

Journal of Petrology

View full text Add to dashboard Cite

We performed phase equilibrium experiments on a natural Ca-poor pelite at 3 GPa, 750-1000 °C, under moderately oxidizing conditions, simulating the partial melting of such lithologies in subduction zones. Experiments investigated the effect of sulphur addition on phase equilibria and compositions, with S contents of up to ∼ 2.2 wt. %. Run products were characterized for their major and trace element contents, in order to shed light on the role of sulphur on the trace element patterns of melts produced by partial melting of oceanic Ca-poor sediments. Results show that sulphur addition leads to the replacement of phengite by biotite along with the progressive consumption of garnet, which is replaced by an orthopyroxene-kyanite assemblage at the highest sulphur content investigated. All Fe-Mg silicate phases produced with sulphur, including melt, have higher MgO/(MgO+FeO) ratios (relative to S-free/poor conditions), owing to Fe being primarily locked up by sulphide in the investigated redox range. Secular infiltration of the mantle wedge by such MgO and K2O-rich melts may have contributed to the Mg and K-rich character of the modern continental crust. Addition of sulphur does not affect significantly the stability of the main accessory phases controlling the behaviour of trace elements (monazite, rutile and zircon), although our results suggest that monazite solubility is sensitive to S content at the conditions investigated. The low temperature (∼ 800 °C) S-bearing and Ca-poor sediment sourced slab melts show Th and La abundances, Th/La systematics and HFSE signatures in agreement with the characteristics of sediment-rich arc magmas. Because high S contents diminish phengite and garnet stabilities, S-rich and Ca-poor sediment sourced slab melts have higher contents of Rb, B, Li (to a lesser extent), and HREE. The highest ratios of La/Yb are observed in sulphur-poor runs (with a high proportion of garnet, which retains HREE) and beyond the monazite out curve (which retains LREE). Sulphides appear to be relatively Pb-poor and impart high Pb/Ce ratio to coexisting melts, even at high S content. Overall, our results show that Phanerozoic arc magmas from high sediment flux margins owe their geochemical signature to the subduction of terrigenous, sometimes S-rich, sediments. In contrast, subduction of such lithologies during Archean appears unlikely or unrecorded.

show abstract

Tectono-magmatic controls on decratonic gold deposits

Chang

Audétat

2021

Contrib Mineral Petrol

View full text Add to dashboard Cite

Magmatic-hydrothermal gold–copper deposits in post-subduction settings represent essential targets for mineral exploration, but controls on their formation remain controversial. The early Cretaceous lode Au districts that formed during lithosphere destruction of the North China Craton provide an ideal opportunity to better understand the key tectono-magmatic factors responsible for the genesis of Au-rich deposits in post-subduction settings. Here, we present a LA-ICP-MS study of silicate melt inclusions and sulfide inclusions from ore-related mafic to intermediate rocks in the central Taihangshan Au district in the interior of the North China Craton to constrain the content and evolution of magmatic ore metals ± volatiles. The results, combined with numerical modeling, suggest that the ore-related magmas contained only a few ng/g Au, which is similar to the Au content of non-mineralization-related mafic to intermediate magmas worldwide. The low Au content of the lode Au-related magmas suggest that large volumes of magmas had to accumulate in the middle to lower crust through trans-lithospheric fault systems to produce the lode Au deposits. It is further suggested that the lode Au-related magmas were alkali-rich, hydrous, oxidized and relatively rich in sulfur and chlorine (mafic melt inclusions contain 0.14‒0.24 wt% S and 0.1‒0.2 wt% Cl). These properties are considered critical for the generation of auriferous ore fluids. By comparing the tectono-magmatic setting of the giant Jiaodong Au province (~ 4000 t Au) with the central Taihangshan district (~ 150 t Au), we propose that the much larger total Au tonnage of the Jiaodong district results from the accumulation of a much larger volume of ore-forming magmas at deep crustal levels, induced by a stronger degree of lithosphere modification. In addition, given that the composition of lode Au-related magmas is similar to that of porphyry Cu–Au-related magmas, the lack of giant, early Cretaceous porphyry Cu–Au deposits in the North China Craton suggests that strong extensional settings favor the formation of lode Au deposits instead of porphyry Cu–Au deposits. The present study, therefore, has general implications for the genesis of Au-rich deposits in strongly extensional settings.

show abstract

An essential role for sulfur in sulfide-silicate melt partitioning of gold and magmatic gold transport at subduction settings

Cited by 40 publications

References 66 publications

Gold in Mineralized Volcanic Systems from the Lesser Khingan Range (Russian Far East): Textural Types, Composition and Possible Origins

Gold in Mineralized Volcanic Systems from the Lesser Khingan Range (Russian Far East): Textural Types, Composition and Possible Origins

The Role of Sulphur on the Melting of Ca-Poor Sediment and on Trace Element Transfer in Subduction Zones: An Experimental Investigation

Tectono-magmatic controls on decratonic gold deposits

Contact Info

Product

Resources

About