Relations of ammonium minerals at several hydrothermal systems in the western U.S.

Krohn, M. Dennis; Kendall, Carol; Evans, John R.; Fries, T.L.

doi:10.1016/0377-0273(93)90005-c

Cited by 49 publications

(23 citation statements)

References 12 publications

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“…Ammoniacal hydrothermal brines < 500 ppm NH þ 4 À Á sometimes completely replace plagioclase with buddingtonite (Barker, 1964;Erd et al, 1964). Most natural occurrences of buddingtonite and other ammonium silicates are in hydrothermally altered rocks, and primarily in gold-and/or mercury-hosting rocks and shales (Bottrell and Miller, 1990;Krohn et al, 1993;Voncken et al, 1993). In the Carlin gold ore deposits (Nevada), buddingtonite is locally abundant and even dominates one massif 8 km across.…”

Section: Ammonium Silicatesmentioning

confidence: 97%

Modeling ammonia–ammonium aqueous chemistries in the Solar System’s icy bodies

Marion

Kargel

Catling

et al. 2012

Icarus

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Section: Ammonium Silicatesmentioning

confidence: 97%

Modeling ammonia–ammonium aqueous chemistries in the Solar System’s icy bodies

Marion

Kargel

Catling

et al. 2012

Icarus

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“…During progressive metamorphism resulting in progressive loss of N and other volatile and mobile elements, the form of released nitrogen may be molecular nitrogen (N 2 ) or ammonia (NH 3 ), given that both species have been documented in fluid inclusions in hydrothermal systems (Bottrell et al, 1988;Krohn et al, 1993;Yardley et al, 1993;de Ronde et al, 1992;Mariner et al, 2003). Accordingly, the enrichment of 15 N may be caused by isotope exchange reactions between silicate-hosted ammonium and either volatile molecular nitrogen or ammonia.…”

Section: Nitrogen Isotope Fractionationmentioning

confidence: 97%

Nitrogen isotope fractionations during progressive metamorphism: A case study from the Paleozoic Cooma metasedimentary complex, southeastern Australia

Jia

2006

Geochimica et Cosmochimica Acta

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“…Ore deposits are remnants of ancient hydrothermal systems and, like their modern counterparts, some are associated with elevated nitrogen concentration (>1000 mg N kg −1 ; Table 5), likely the result of hydrothermal mobilization of nitrogen from organic matter associated with sedimentary host rock [ Krohn et al , 1993; Kydd and Levinson , 1986]. The 15‰ range (−0.9 to +14.2‰) of δ 15 N in ammonium minerals in the western United States does not indicate any single source for the nitrogen [ Krohn et al , 1993]. Ammonium appeared to be preferentially partitioned into white mica and fuchsite, a chromium mica, relative to biotite and vanadium mica during hydrothermal alteration [ Jia and Kerrich , 1999].…”

Section: Nitrogen Cycling and Geologic Processesmentioning

confidence: 99%

Nitrogen in rock: Occurrences and biogeochemical implications

Holloway

Dahlgren²

2002

Global Biogeochemical Cycles

217

161

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[1] There is a growing interest in the role of bedrock in global nitrogen cycling and potential for increased ecosystem sensitivity to human impacts in terrains with elevated background nitrogen concentrations. Nitrogen-bearing rocks are globally distributed and comprise a potentially large pool of nitrogen in nutrient cycling that is frequently neglected because of a lack of routine analytical methods for quantification. Nitrogen in rock originates as organically bound nitrogen associated with sediment, or in thermal waters representing a mixture of sedimentary, mantle, and meteoric sources of nitrogen. Rock nitrogen concentrations range from trace levels (<200 mg N kg À1 ) in granites to ecologically significant concentrations exceeding 1000 mg N kg À1 in some sedimentary and metasedimentary rocks. Nitrate deposits accumulated in arid and semi-arid regions are also a large potential pool. Nitrogen in rock has a potentially significant impact on localized nitrogen cycles. Elevated nitrogen concentrations in water and soil have been attributed to weathering of bedrock nitrogen. In some environments, nitrogen released from bedrock may contribute to nitrogen saturation of terrestrial ecosystems (more nitrogen available than required by biota). Nitrogen saturation results in leaching of nitrate to surface and groundwaters, and, where soils are formed from ammonium-rich bedrock, the oxidation of ammonium to nitrate may result in soil acidification, inhibiting revegetation in certain ecosystems. Collectively, studies presented in this article reveal that geologic nitrogen may be a large and reactive pool with potential for amplification of human impacts on nitrogen cycling in terrestrial and aquatic ecosystems.

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Relations of ammonium minerals at several hydrothermal systems in the western U.S.

Cited by 49 publications

References 12 publications

Modeling ammonia–ammonium aqueous chemistries in the Solar System’s icy bodies

Modeling ammonia–ammonium aqueous chemistries in the Solar System’s icy bodies

Nitrogen isotope fractionations during progressive metamorphism: A case study from the Paleozoic Cooma metasedimentary complex, southeastern Australia

Nitrogen in rock: Occurrences and biogeochemical implications

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