Boron, sulphur and copper isotope systematics in the orogenic gold deposits of the Archaean Hattu schist belt, eastern Finland

Molnár, Ferenc; Mänttäri, Irmeli; O’Brien, Hugh; Lahaye, Yann; Pakkanen, Lassi; Johanson, Bo; Käpyaho, Asko; Sorjonen-Ward, Peter; Whitehouse, Martin J.; Sakellaris, Grigorios

doi:10.1016/j.oregeorev.2016.02.012

Cited by 56 publications

(23 citation statements)

References 72 publications

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“…For another sample, trace elements were additionally analyzed by ICP-MS at the University of Cape Town (Table 2). One sample was analyzed for S isotopes using laser ICP-MS at the Geological Survey of Finland (see Molnár et al 2016 for analytical details). In another sample, we determined Sr isotopes in plagioclase, also by laser ICP-MS in Finland (see Yang et al 2013 for analytical details).…”

Section: Methodsmentioning

confidence: 99%

A chilled margin of komatiite and Mg-rich basaltic andesite in the western Bushveld Complex, South Africa

Maier

Barnes

2016

Contrib Mineral Petrol

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Section: Methodsmentioning

confidence: 99%

A chilled margin of komatiite and Mg-rich basaltic andesite in the western Bushveld Complex, South Africa

Maier

Barnes

2016

Contrib Mineral Petrol

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“…It is for these reasons that the use of stable B-isotopes in tourmaline has become well established in the study of ore deposits (e.g. Palmer and Slack, 1989;Xavier et al, 2008;Garda et al, 2009;Slack and Trumbull, 2011;Tornos et al, 2012;Duncan et al, 2014;Molnár et al, 2016). While boron isotope analysis by thermal ionization mass spectrometry (TIMS) requires complete chemical dissolution of a bulk tourmaline sample, secondary ion mass spectrometry (SIMS) allows for texturally resolved measurement of δ 11 B in tourmaline at levels of precision that allow detailed analysis of fluid source reservoirs in relation to the mineral paragenesis.…”

Section: Introductionmentioning

confidence: 99%

Discriminating fluid source regions in orogenic gold deposits using B-isotopes

Lambert-Smith

Rocholl

Treloar

et al. 2016

Geochimica et Cosmochimica Acta

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The genesis of orogenic gold deposits is commonly linked to hydrothermal ore fluids derived from metamorphic devolatilisation reactions. However, there is considerable debate as to the ultimate source of these fluids and the metals they transport. Tourmaline is a common gangue mineral in orogenic gold deposits. It is stable over a very wide P-T range, demonstrates limited volume diffusion of major and trace elements and is the main host of B in most rock types. We have used texturally resolved B-isotope analysis

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“…A possible explanation for this shift between the two studies on the Athabasca Basin is that Mercadier et al [33] did not use matrix-match standards (but elbaite standard) while dravite standards were used by Adlakha et al [32] and in this study. It is now well documented that matrix-dependent mass fractionation during SIMS analysis of boron isotopes in tourmaline could be significant [51,66,67]. Whether the data of Mercadier et al [33] should be corrected significantly and, if so, determining the magnitude of the correction is beyond the scope of this study.…”

Section: Comparison Between Unconformity-related Deposits Of the Allimentioning

confidence: 86%

Insights into B-Mg-Metasomatism at the Ranger U Deposit (NT, Australia) and Comparison with Canadian Unconformity-Related U Deposits

et al. 2019

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The Ranger deposit (Northern Territory, Australia) is one of the largest uranium deposits in the world. Uranium mineralisation occurs in crystalline basement rocks and is thought to belong to the unconformity-related category. In order to address the sources of magnesium and boron, and the temperature of the fluids related to boron and magnesium metasomatism that occurred shortly before and during the main uranium stage, in situ analyses of chlorite and tourmaline were carried out. The chemical composition of tourmaline shows an elevated X-site vacancy and a low Fe tot /(Fe tot + Mg) ratio typical of Mg-foitite. Uranium-related chlorite has relatively low Fe content (0.28-0.83 apfu) and high Mg content (3.08-3.84 apfu), with Si/Al = 1.08−1.22 and Mg/(Mg + Fe tot ) = 0.80−0.93 indicating a composition lying between the clinochlore and Mg-amesite fields. Chlorite composition indicates crystallisation temperature of 101-163 • C. The boron isotopic composition of tourmaline shows a range of δ 11 B values of~1-9% . A model is proposed involving two boron sources that contribute to a mixed isotopic signature: (i) evaporated seawater, which is typically enriched in magnesium and boron (δ 11 B~40% ), and (ii) boron from the crystalline basement (δ 11 B~−30 to +10% ), which appears to be the dominant source. Collectively, the data indicate similar tourmaline chemistry but significant differences of tourmaline boron isotopic composition and chlorite chemistry between the Ranger deposit and some of the Canadian unconformity-related uranium deposits. However, lithogeochemical exploration approaches based on identification of boron-and magnesium-enriched zones may be usefully applied to uranium exploration in the Northern Territory.

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Boron, sulphur and copper isotope systematics in the orogenic gold deposits of the Archaean Hattu schist belt, eastern Finland

Cited by 56 publications

References 72 publications

A chilled margin of komatiite and Mg-rich basaltic andesite in the western Bushveld Complex, South Africa

A chilled margin of komatiite and Mg-rich basaltic andesite in the western Bushveld Complex, South Africa

Discriminating fluid source regions in orogenic gold deposits using B-isotopes

Insights into B-Mg-Metasomatism at the Ranger U Deposit (NT, Australia) and Comparison with Canadian Unconformity-Related U Deposits

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