Genesis of sediment-hosted disseminated-gold deposits by fluid mixing and sulfidization: Chemical-reaction-path modeling of ore-depositional processes documented in the Jerritt Canyon district, Nevada

Hofstra, Albert H.; Leventhal, Joel S.; Northrop, H. Roy; Landis, Gary P.; Rye, Robert O.; Birak, Donald J.; Dahl, A. R.

doi:10.1130/0091-7613(1991)019<0036:goshdg>2.3.co;2

Cited by 120 publications

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“…Growth of the particle during exposure to a gold solution could lead to a higher gold concentration, due to the substrate which continues to provide a new surface for Au sorption. Pyritization has been proposed to be an effective mechanism of gold precipitation from ore-forming solutions (Hofstra et al, 1991;Stenger et al, 1998a) on account of the decreasing H2S fugacity of the solution (Kuehn and Rose, 1995). However, the association of SHDG deposits and organic matter, the spatial association of SHDG deposits with ancient and modern oil traps, and also the high 6 34 S values of the auriferous pyrite all suggest this would not be the case.…”

mentioning

confidence: 87%

“…Studies have examined stable isotope composition variation and the degree of pyritization around deposits, and have proposed potential applications to geochemical exploration (Hofstra et al, 1991;Stenger et al, 1998a,b;Woitsekhowskaya and Peters, 1998). However, studies on trace elements, including high field strength and rare earth elements in the ores and the altered host rocks, are rare.…”

Section: Rare Earth Elements and High Field Strength Elementsmentioning

confidence: 99%

“…Fluid-inclusion, oxygen and hydrogen stable-isotope studies at the Carlin (Kuehn and Rose, 1995), Jerritt Canyon (Hofstra et al, 1991) and Alligator Ridge ) deposits indicate that ore fluids were deeply circulating as evolved meteoric fluids.…”

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confidence: 99%

“…Some of the deposits are associated with intrusive rocks spatially but not temporally and genetically. Since geological data indicates that igneous activity predated gold mineralization, there is, therefore, no evidence that links mineralization and igneous activity (Hofstra, et al, 1991) with the exception of a few so called Carlin-like deposits, such as the Lone Tree deposit (Doebrich and Theodore, 1996).…”

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confidence: 99%

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Geochemistry of the sediment-hosted disseminated gold deposits in Southwestern Guizhou Province, China /

Bao¹

2001

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confidence: 87%

Section: Rare Earth Elements and High Field Strength Elementsmentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

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Geochemistry of the sediment-hosted disseminated gold deposits in Southwestern Guizhou Province, China /

Bao¹

2001

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“…Studies have examined stable isotope composition variation and the degree of pyritization of host rock iron around deposits, documented geochemical signatures, and have proposed potential applications to geochemical exploration (Hofstra et al, 1991;Stenger et al, 1998a, b;Woitsekhowskaya and Peters, 1998;Hofstra and Cline, 2000). However, studies focusing on high field strength and rare earth elements in the ores and the altered host rocks are rare.…”

Section: Rare Earth Elements and High Field Strength Elementsmentioning

confidence: 99%

HFSE, REE, and PGE geochemistry of three sedimentary rock-hosted disseminated gold deposits in southwestern Guizhou Province, China

et al. 2004

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The sedimentary rock-hosted disseminated gold (SRHDG) deposits in southwest Guizhou Province, China, are located near the buried edge of the Yangtze Craton. Three deposits, Lannigou, Getang and Zimudang, were chosen for this study. The deposits are hosted by fine-grained clastic and calcareous sedimentary rocks and formed at low temperatures from low salinity solutions of low to intermediate pH and low f O 2 . Chemical analyses of the ores and host rocks show that high field strength elements, such as Nb, Ta, Zr and Hf, were immobile during hydrothermal alteration. However, rare earth elements (REE) were mobile. Light rare earth elements (LREE) were depleted, whereas heavy rare earth elements (HREE) were enriched. A differentiation of platinum group elements (PGE) concentrations was documented. The ores are enriched in Pd and Pt, consistent with the higher solubility of these two elements in ore fluids. The Pd/Ir ratios of the ores are lower than those of the ultramafic rocks and the Emeishan basalts in the region. Thus, the ultramafic intrusives and basalts could not have been the main source of the PGEs and gold in the SRHDG deposits. Rather, these metals were derived mainly from the sedimentary host rocks as evidenced by the trace element and stable isotopic characteristics of the ores.Our data suggest that the SRHDG deposits in southwest Guizhou are most likely of amagmatic origin, which is consistent with the lack of igneous intrusives in the vicinity of the deposits, the very weak metamorphic grade of the rocks, the lack of metamorphic effects within the time range of the SRHDG deposits, and coincidence in time of gold mineralization with regional extension.

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Trace elements and in situ sulfur isotopes of pyrite from the Baiyunpu Au deposit in central Hunan, South China: Implications for gold mineralization

Gao

Shen

et al. 2022

Geological Journal

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The Central Hunan metallogenic province, located in the southeastern part of the Yangtze Block, South China, is one of the most important Sb–Au metallogenic belts in China. The Baiyunpu gold deposit is one of the important Carlin‐type gold deposits occurring in Devonian sedimentary strata in Central Hunan. Optical microscopy and in situ laser ablation (multi‐collector) inductively coupled plasma mass spectrometry (LA‐[MC]‐ICP‐MS) are used to determine the texture, trace element compositions and sulfur isotope for pyrites from the pre‐ore and syn‐ore stages to constrain the sources of reduced sulfur and metals and the mechanism of gold precipitation. Four generations of pyrite were identified by petrography and pyrite compositions. Pre‐ore Py1 is characterized by relatively low concentrations of As, Au, Sb and Cu and high concentrations of Co, Ni, Bi and Pb. Py1 has positive δ34S values of 6.5–10.1‰, which we ascribe to a bacterial reduction of marine sulfate in closed marine systems, or from weak Rayleigh fractionation by bacterial sulfate reduction (BSR) or thermochemical sulfate reduction (TSR) during sedimentary‐diagenetic processes. Pre‐ore Py2 presents as rims of Py1 and contains relatively high As (69,530 ppm), Sb (123.2 ppm) and low Au (4.89 ppm). Compared with Py2, Py3 has relatively high Au (194.4 ppm) and Cu (24.6 ppm) and low As (40,801 ppm). We interpret that Py2 and Py3 could have precipitated from an Au‐free but As‐rich early hydrothermal fluids or from low‐Au and As‐rich fluids at the beginning of the ore stage. The δ34S values of Py2 and Py3 in the Baiyunpu deposit are concentrated in a narrow range of −1.2 to 1.2‰, suggesting the involvement of magmatic sulfur. Syn‐ore pyrites (Opy) are enriched in Au (517.8 ppm), As (39,719 ppm), Cu (261.9 ppm) and Sb (171.4 ppm). Irregular boundaries between Py1 and Opy suggest that the replacement may have been important for the formation of pyrites at the syn‐ore stage. The variation of As concentration in Opy1, Opy2 and Opy3 appear to have recorded fluctuations in the chemical composition of ore fluids. The δ34S values of Opy (0.1–5.9‰) are slightly higher than Py2 and Py3 due to mixing with sedimentary components with elevated δ34S values in late‐stage hydrothermal fluids. Profile analyses for Baiyunpu auriferous pyrite grains suggest that Au was positively correlated with Cu, but not with As. The correlation between Au, Cu and As in Opy may be dominated by their concentrations of ambient evolving fluids.

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Genesis of sediment-hosted disseminated-gold deposits by fluid mixing and sulfidization: Chemical-reaction-path modeling of ore-depositional processes documented in the Jerritt Canyon district, Nevada

Cited by 120 publications

References 0 publications

Geochemistry of the sediment-hosted disseminated gold deposits in Southwestern Guizhou Province, China /

Geochemistry of the sediment-hosted disseminated gold deposits in Southwestern Guizhou Province, China /

HFSE, REE, and PGE geochemistry of three sedimentary rock-hosted disseminated gold deposits in southwestern Guizhou Province, China

Trace elements and in situ sulfur isotopes of pyrite from the Baiyunpu Au deposit in central Hunan, South China: Implications for gold mineralization

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