Effects of fluid boiling on Au and volatile element enrichment in submarine arc-related hydrothermal systems

Falkenberg, Jan J.; Keith, Manuel; Haase, Karsten M.; Bach, Wolfgang; Klemd, Reiner; Strauß, Harald; Yeo, Isobel; Rubin, K. H.; Storch, Bettina; Anderson, Melissa O.

doi:10.1016/j.gca.2021.05.047

Cited by 41 publications

(66 citation statements)

References 117 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Similar trace element concentrations in pyrite between the two vent sites were observed for Ge and Ag. Compared to pyrite from Niua South (Falkenberg et al, 2021), pyrite from Maka rather exhibits a depleted trace element signature and enrichments compared to the former were only observed for Mn, Ni, Se, Te and Bi at Maka HF and Cu at both vent sites. Hydrothermal pyrite from Maka is enriched in most trace elements, except Mn and Ni, relative to the volcanic glass samples from the seafloor lavas (Figure 3).…”

Section: Major and Trace Elements In Hydrothermal Sulphidesmentioning

confidence: 66%

“…In addition to the leaching process, metals may be contributed by magmatic volatiles, as known from island arc and some back-arc hydrothermal systems (de Ronde et al, 2011;Keith et al, 2018;Seewald et al, 2019;Fox et al, 2020;Martin et al, 2020). As the hot (up to 400 °C), low pH (2-4) and metal-bearing fluid rises towards the seafloor strong physicochemical gradients (e.g., temperature, pH, redox, ligand availability) lead to the formation of (subsurface) hydrothermal precipitates due to processes like fluid boiling and fluid-seawater mixing (Diehl et al, 2020;Falkenberg et al, 2021;Keith et al, 2021;Schaarschmidt et al, 2021). Previous studies highlighted that fluid boiling is an efficient process for metal fractionation and precipitation in arc and back-arc hydrothermal systems due to temperature-pressure conditions below the critical point of seawater at 408 °C and 301.1 bars (i.e., 3,060 m water depth; Stoffers et al, 2006;Monecke et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

“…Depending on their volatility the dissolved elements either partition into the vapour (e.g., As, Sb, Te) or liquid phase (e.g., Fe, Co, Ni) and/or precipitate (e.g., Au) as a consequence of boiling-induced changes in fluid pH, redox, and ligand availability (e.g., Cl, H 2 S; Drummond and Ohmoto, 1985;Grundler et al, 2013;Monecke et al, 2014;Pokrovski et al, 2018). Although, liquid-vapour partitioning and precipitation affect fluid chemistry in predictable ways (e.g., Von Damm et al, 1997;Stoffers et al, 2006;Schmidt et al, 2017) it is still unclear how these processes are recorded in the geological archive by sulphide chemistry (Tardani et al, 2017;Román et al, 2019;Keith et al, 2020;Falkenberg et al, 2021;Nestmeyer et al, 2021;Schaarschmidt et al, 2021).…”

Section: Introductionmentioning

confidence: 99%

“…The chemical composition of vent fluids in active systems is highly beneficial for understanding the ongoing hydrothermal processes, but provides only limited information on the temporal evolution of the hydrothermal system (Von Damm et al, 1997;Schmidt et al, 2017;Humphris and Klein, 2018). To date, time-series data from island arcs and adjacent back-arcs are scarce and underrepresented on a global scale, however, recent investigations of hydrothermal fluids and precipitates from the Southwest Pacific, suggest additional short-lived processes (days to months) affecting the geochemical composition of hydrothermal fluids, which is documented by the mineralogy and chemistry of the precipitates from active and inactive vents and chimney talus (Ditchburn et al, 2012;Berkenbosch et al, 2015Berkenbosch et al, , 2019Seewald et al, 2015;Kleint et al, 2019;Diehl et al, 2020;Falkenberg et al, 2021). The complex physical, chemical and temporal aspects that control the chemical composition of hydrothermal fluids also directly influence the associated hydrothermal precipitates (Ditchburn et al, 2012;Berkenbosch et al, 2019;Keith et al, 2021).…”

Section: Introductionmentioning

confidence: 99%

“…The complex physical, chemical and temporal aspects that control the chemical composition of hydrothermal fluids also directly influence the associated hydrothermal precipitates (Ditchburn et al, 2012;Berkenbosch et al, 2019;Keith et al, 2021). The sampling of submarine hydrothermal vent systems is challenging and in contrast to the fluid compositions that represent a snapshot in time, associated hydrothermal precipitates accumulate and can document changing processes affecting the fluids during the evolution of the hydrothermal system (de Ronde et al, 2011;Fouquet et al, 2018;Berkenbosch et al, 2019;Diehl et al, 2020;Falkenberg et al, 2021).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Trace Element and Isotope Systematics in Vent Fluids and Sulphides From Maka Volcano, North Eastern Lau Spreading Centre: Insights Into Three-Component Fluid Mixing

et al. 2021

Self Cite

View full text Add to dashboard Cite

Back-arc spreading centres and related volcanic structures are known for their intense hydrothermal activity. The axial volcanic edifice of Maka at the North Eastern Lau Spreading Centre is such an example, where fluids of distinct composition are emitted at the Maka hydrothermal field (HF) and at Maka South in 1,525–1,543 m water depth. At Maka HF black smoker-type fluids are actively discharged at temperatures of 329°C and are characterized by low pH values (2.79–3.03) and a depletion in Mg (5.5 mmol/kg) and SO4 (0.5 mmol/L) relative to seawater. High metal (e.g., Fe up to ∼6 mmol/kg) and rare Earth element (REE) contents in the fluids, are indicative for a rock-buffered hydrothermal system at low water/rock ratios (2–3). At Maka South, venting of white smoke with temperatures up to 301°C occurs at chimneys and flanges. Measured pH values range from 4.53 to 5.42 and Mg (31.0 mmol/kg), SO4 (8.2 mmol/L), Cl (309 mmol/kg), Br (0.50 mmol/kg) and Na (230 mmol/kg) are depleted compared to seawater, whereas metals like Li and Mn are typically enriched together with H2S. We propose a three-component mixing model with respect to the fluid composition at Maka South including seawater, a boiling-induced low-Cl vapour and a black smoker-type fluid similar to that of Maka HF, which is also preserved by the trace element signature of hydrothermal pyrite. At Maka South, high As/Co (>10–100) and Sb/Pb (>0.1) in pyrite are suggested to be related to a boiling-induced element fractionation between vapour (As, Sb) and liquid (Co, Pb). By contrast, lower As/Co (<100) and a tendency to higher Co/Ni values in pyrite from Maka HF likely reflect the black smoker-type fluid. The Se/Ge ratio in pyrite provides evidence for fluid-seawater mixing, where lower values (<10) are the result of a seawater contribution at the seafloor or during fluid upflow. Sulphur and Pb isotopes in hydrothermal sulphides indicate a common metal (loid) source at the two vent sites by host rock leaching in the reaction zone, as also reflected by the REE patterns in the vent fluids.

show abstract

Section: Major and Trace Elements In Hydrothermal Sulphidesmentioning

confidence: 66%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Trace Element and Isotope Systematics in Vent Fluids and Sulphides From Maka Volcano, North Eastern Lau Spreading Centre: Insights Into Three-Component Fluid Mixing

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

Trace-element distribution and ore-forming processes in Au–Ag-rich hydrothermal chimneys and mounds in the TA25 West vent field of the Tonga Arc

et al. 2022

View full text Add to dashboard Cite

We report detailed mineralogy and geochemistry of hydrothermal mounds and chimneys in the TA25 West vent field (TA25 WVF), a newly discovered magmatic–hydrothermal system in the Tonga (Tofua) arc. Chimney samples are classified as sulfate- or sulfide-rich, based on major sulfide, sulfosalt, and sulfate minerals. The former type represents a simple mineral assemblage of predominance of anhydrite/gypsum + barite + pyrite, whereas the sulfide-rich chimneys show three different stages of mineralization with decreasing fluid temperature: sphalerite–pyrite dominated stage I, sphalerite–sulfosalts dominated stage II, and stage III is dominated by seawater alteration. Mound samples are characterized by sulfide assemblages and paragenesis similar to those of sulfide-rich samples, but abundant chalcopyrite indicates a relatively high-temperature mineralization. The chimney and mound samples are enriched in Au (average 9.2 ppm), Ag (297 ppm), As (1897 ppm), Sb (689 ppm), Hg (157 ppm), and Se (34.6 ppm). LA–ICP–MS and FE–TEM studies indicate that most of these elements occur in sulfides or sulfosalts in solid solution, although some occur as nanoparticles. This is mainly controlled by the combined effects of fluid conditions (temperature and redox state) and influx of ambient seawater. Petrography and trace-element compositions of sulfides and/or sulfosalts suggest that most concentrations of Au and Ag in the TA25 WVF result from the precipitation and/or adsorption of Au–Ag-bearing nanoparticles on rapidly crystallized sulfides, the substitution of Au and Ag in sulfide and/or sulfosalt minerals, and the saturation of Ag in hydrothermal fluids during late, relatively low-temperature mineralization (< 150 °C). The maximum measured temperature (242 °C) of venting fluids and calculated formation temperatures of sphalerite (229–267 ℃) are below the boiling temperature of seawater at the depths (966–1096 m) of the TA25 WVF, suggesting fluid boiling had little effect on Au–Ag-rich mineralization in the TA25 WVF. The presence of enargite–tetrahedrite–tennantite assemblages, high concentrations of magma-derived elements (e.g., Au, Ag, As, Sb, Hg, and Se), low δ34S values (2.1 to 4.3‰) of sulfide minerals relative to the host rocks, and the distribution of CO2-rich hydrothermal plumes (500 to 1000 ppm) suggest that the TA25 WVF is a submarine hydrothermal system influenced by a magmatic contribution in an arc setting. Our results indicate that the magmatic contribution is most likely to play an important role in supplying various metals, including Au and Ag, to the TA25 WVF. Subsequently, the rapid crystallization of sulfides induced by abundant fluid-seawater mixing significantly contributes to the precipitation of Au–Ag-rich mineralization.

show abstract

Sources, transport, and deposition of metal(loid)s recorded by sulfide and rock geochemistry: constraints from a vertical profile through the epithermal Profitis Ilias Au prospect, Milos Island, Greece

et al. 2023

Self Cite

View full text Add to dashboard Cite

Drill core samples from the Profitis Ilias Pb-Zn-Cu-Ag-Au vein mineralization on Milos Island, Greece provide new insights into (i) the metal sources, (ii) the primary vertical metal(loid) distribution, and (iii) the supergene enrichment processes in a transitional shallow-marine to subaerial hydrothermal environment. Metal contents of unaltered and altered host rocks combined with Pb isotope analyses of hydrothermal sulfides suggest that most metal(loid)s were derived by leaching of basement rocks, whereas the distinct enrichment of Te is related to the addition of Te by a magmatic fluid. The trace element contents of base metal sulfides record decreasing Au, Te, Se, and Co, but increasing Ag, Sb, and Tl concentrations with increasing elevation that can be related to progressive cooling and fluid boiling during the hypogene stage. The formation of base metal veins with porous pyrite hosting hessite inclusions at ~ 400 m below the surface was triggered by vigorous fluid boiling. By contrast, the enrichment of native Au associated with oxidized Fe and Cu phases in the shallower part of the hydrothermal system resulted from supergene remobilization of trace Au by oxidizing meteoric water after tectonic exhumation to subaerial levels. Disseminated pyrite with higher Tl/Pb ratios and locally elevated Hg concentrations relative to vein pyrite reflects infiltration of the host rocks by boiled liquids and condensed vapor fluids. The vertical and temporal evolution of the Profitis Ilias mineralization, therefore, provides unique insights into the transport and precipitation of Au, Ag, Te, and related metal(loid)s by multiple fluid processes.

show abstract

Effects of fluid boiling on Au and volatile element enrichment in submarine arc-related hydrothermal systems

Cited by 41 publications

References 117 publications

Trace Element and Isotope Systematics in Vent Fluids and Sulphides From Maka Volcano, North Eastern Lau Spreading Centre: Insights Into Three-Component Fluid Mixing

Trace Element and Isotope Systematics in Vent Fluids and Sulphides From Maka Volcano, North Eastern Lau Spreading Centre: Insights Into Three-Component Fluid Mixing

Trace-element distribution and ore-forming processes in Au–Ag-rich hydrothermal chimneys and mounds in the TA25 West vent field of the Tonga Arc

Sources, transport, and deposition of metal(loid)s recorded by sulfide and rock geochemistry: constraints from a vertical profile through the epithermal Profitis Ilias Au prospect, Milos Island, Greece

Contact Info

Product

Resources

About