The role of organic acid in the abiogenic reduction of sulfate and the sulfur isotope effect.

Kiyosu, Yasuhiro; Krouse, H. R.

doi:10.2343/geochemj.24.21

Cited by 159 publications

(101 citation statements)

References 16 publications

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“…In addition, this trend is consistent with the results of abiogenic reduction of sulfate reported by Kiyosu (1980) and Kiyosu and Krouse (1990). However, the O34S values of the sulfur com pounds are fairly variable compared with those previously reported.…”

Section: Resultssupporting

confidence: 81%

“…The rate constants (per minute) for the temperature of 223 to 270°C vary from 5.4x 10-5 to 6.8 x10-4 (mina-'), respectively. Kiyosu and Krouse (1990) reported first-order constants for the reduction of sulfuric acid by acetic acid over the same temperature range of 2.2 x 10-6 to 1.4 x l0-4 (min.-'), which are slightly smaller than the values obtained for the present experi ment. …”

Section: Discussioncontrasting

confidence: 53%

“…This result is consi tent with that of the abiogenic reduction of sulfuric acid by dextrose as reported in Kiyosu (1980), except for the temperature range. However, when sulfuric acid is thermochemical ly reduced by acetic acid at temperatures above 250°C (Kiyosu and Krouse, 1990), hydrogen sulfide is not produced until the sulfate disap pears.…”

Section: Resultsmentioning

confidence: 99%

“…and yields an activation energy of 120.6 kJ /mole (28.8 kcal mole-'), a low value compared with those in other abiogenic sulfate reductions (e.g., see Kiyosu and Krouse, 1990). The activation energy in sulfuric acid-acetic acid systems has been described in detail by Kiyosu and Krouse (1990).…”

Section: Discussionmentioning

confidence: 99%

“…Taking this into consideration, a study of thermochemical sulfate reduction by organic acids derived from kerogen that exists in sedimentary rocks was conducted (Kiyosu and Krouse, 1990). The study determined the reduc tion rate of the sulfuric acid by acetic acid and the sulfur isotope effects.…”

Section: Introductionmentioning

confidence: 99%

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Thermochemical reduction and sulfur isotopic behavior of sulfate by acetic acid in the presence of native sulfur.

Kiyosu

Krouse

1993

Geochem. J.

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Section: Resultssupporting

confidence: 81%

Section: Discussioncontrasting

confidence: 53%

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Thermochemical reduction and sulfur isotopic behavior of sulfate by acetic acid in the presence of native sulfur.

Kiyosu

Krouse

1993

Geochem. J.

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Ore genesis of the Xiyi Pb‐Zn deposit, western Yunnan province, China: Geologic, fluid inclusion, and isotopic (C‐H‐O‐S‐Pb) evidence

Gao

Zhang

et al. 2017

Geological Journal

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The Xiyi Pb‐Zn deposit, located in the Baoshan Block of the Sanjiang region in western Yunnan, China, contains 1.2 Mt of Pb‐Zn resources. The orebodies are hosted by Devonian‐Carboniferous limestone, structurally controlled by the NE‐trending fractures, and occur in stratiform, vein, and lenticular forms. The mineral assemblage of the ores includes sphalerite, galena, pyrite, arsenopyrite, chalcopyrite, and marcasite. Calcite, barite, and quartz occur as gangue minerals. Three stages of hydrothermal mineralization are recognized based on the ore textures, crosscutting relationship, and mineral assemblages: an early stage of sphalerite + galena + calcite (Stage 1), a middle stage of galena + arsenopyrite + calcite ± sphalerite (Stage 2), and a late stage of calcite + pyrite ± barite ± quartz (Stage 3). Two types of fluid inclusions are associated with the different ore‐forming hydrothermal stages: aqueous inclusions and hydrocarbon‐H2O inclusions. The ore‐forming fluids were characterized by low temperatures (100 ~ 200 °C), medium salinities (8 ~ 20 wt% NaCleq), and medium densities (1.0 ~ 1.1 g/cm3) and contained minor amounts of CH4. The δDH2O and calculated δ18OH2O values of the Stage 1 calcite range from −89‰ to −103‰ and from 1.5‰ to 5.5‰, respectively, indicating that the H2O in the hydrothermal fluids was derived from seawater that had reacted with organic matter. The δ13CPDB and δ18OSMOW values of the calcite associated with Stages 1 and 3 range from −5.2‰ to 3.2‰ and from 12.5‰ to 20.0‰, respectively. These data plot in the field between marine carbonate and granites and are close to the marine carbonate field, suggesting that the CO2 in the ore‐forming fluids was derived from the dissolution of marine carbonate in the sedimentary rocks. The galena, sphalerite, and pyrite in Stages 1 and 3 have a narrow range of δ34S values (0–3‰), which is lower than the δ34S values of early Carboniferous to Middle‐Late Devonian seawater sulfate (+18‰ to +23‰). Therefore, because the mineralization is unrelated to magmatic activity, the sulfur in the hydrothermal sulfides was derived from regional marine sulfates primarily via organic reduction at temperatures of 100 to 200 °C. The lead isotopic compositions in the galena, sphalerite, and pyrite in Stages 1 and 3 are very similar to those in the diagenetic pyrite in the host rocks, plotting in the field of the upper crust Pb evolution curve. Thus, the lead source was likely the Carboniferous and Devonian strata. The geologic, fluid inclusion, and isotopic (C‐H‐O‐S‐Pb) evidence in this study suggests that the Xiyi Pb‐Zn deposit is a Mississippi Valley‐type deposit.

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Geological and geochemical constraints on the genesis of the Xiqianluzi Pb–Zn polymetallic deposit in Beishan, Gansu Province, NW China

et al. 2022

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The Xiqianluzi Pb–Zn polymetallic deposit is located in the southeast of the southern Beishan belt, whereas the ore‐forming metal sources are still unclear. Its Pb–Zn ore bodies mainly occur in the Changcheng system Qianluzigou Group metamorphic clastic rocks, showing zonation of Cu–Zn–Pb metals from deep to surface. The ore structures are mainly banded, massive and veined, which have the characteristics of syngenetic sedimentation. Au mineralization in silty slate is obviously controlled by WNW–ESE‐trending faults, and occurs as veined or lenticular type. The Pb, Zn, Cu, and Au are mainly enriched in quartz or siliceous veins. The biotite granodiorites are enriched in Si, Na, Rb, Ba and K, with A/CNK values less than 1.1, and depleted in Nb, P, Ti. They belong to calc‐alkalic series and weak peraluminous I‐type granite, formed in a post‐collision extensional environment and characterized by crust–mantle mixed source. The sulphide minerals in the Pb–Zn ores have δ34S values in the range of 17.7‰–21.0‰ with average of 19.2‰, reflecting seawater sulphate origin of sulphur. The sulphur of Pb–Zn ores was likely transformed from S6+ to S2− by thermochemical sulphate reduction. The Pb isotopic compositions of sulphide minerals in the Pb–Zn ores have 206Pb/204Pb ratios of 16.837–17.001, 207Pb/204Pb ratios of 15.437–15.557, and 208Pb/204Pb ratios of 36.377–36.889. In contrast, sulphide minerals in Au ores have δ34S values (5.4‰–7.6‰, with average of 6.5‰) lower than those of sulphide minerals in the Pb–Zn ores. The δ34S values of sulphide minerals in the Au ores are consistent with those of sulphide minerals in the Late Permian–Middle Triassic magmatic hydrothermal gold deposits in the southern Beishan belt, which imply a magmatic source for sulphur. Sulphide minerals in the Au ores have higher lead isotopic ratios, including 206Pb/204Pb of 18.249–18.325, 207Pb/204Pb of 15.583–15.598, and 208Pb/204Pb of 38.023–38.366, compared to those in the Pb–Zn ores. Geological and isotopic features indicate that the Xiqianluzi Pb–Zn polymetallic deposit comprises two mineralization types; namely, its Pb–Zn ores can be considered as Mesoproterozoic sedimentary exhalative type, while its Au ores are magmatic origin. These show that Au mineralization was closely related to the magmatic hydrothermal activities, and thus Au ores can be classified as Late Permian–Early Triassic magmatic hydrothermal Au mineralization.

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The role of organic acid in the abiogenic reduction of sulfate and the sulfur isotope effect.

Cited by 159 publications

References 16 publications

Thermochemical reduction and sulfur isotopic behavior of sulfate by acetic acid in the presence of native sulfur.

Thermochemical reduction and sulfur isotopic behavior of sulfate by acetic acid in the presence of native sulfur.

Ore genesis of the Xiyi Pb‐Zn deposit, western Yunnan province, China: Geologic, fluid inclusion, and isotopic (C‐H‐O‐S‐Pb) evidence

Geological and geochemical constraints on the genesis of the Xiqianluzi Pb–Zn polymetallic deposit in Beishan, Gansu Province, NW China

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