Noble gases in basalt glasses from a Mid-Atlantic Ridge topographic high at 14°N: geodynamic consequences

Staudacher, T.; Sarda, Ph.; Richardson, Stephen H.; Allègre, Claude J.; Sagna, Ibrahima; Dmitriev, L. V.

doi:10.1016/0012-821x(89)90127-1

Cited by 249 publications

(67 citation statements)

References 50 publications

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“…The distinction might be explained by the different method of blank corrections (Raquin et al, 2008). Nevertheless, with the exception of one particularly radiogenic vesicle in Burnard's study (~64,000±8,000), both studies obtained 40 Ar/ 36 Ar of the order of ~40,000 in vesicles from the 2πD43 sample, compatible with the highest ratios measured in MORB, although higher (e.g., Staudacher et al, 1989). …”

Section: Radiogenic Argon In Morb and Oibsupporting

confidence: 67%

“…Later on, Ozima and Zashu (1983) analysed the five noble gases, including argon, on the same MORB samples and obtained radiogenic 40 Ar/ 36 Ar ratios lower than 5600. In three publications, the Paris group obtained ratios as high as 28,150±330 (Allègre et al, 1983b;Sarda et al, 1985;Staudacher et al, 1989) in samples from the Mid Atlantic Ridge (Fig. 4.2).…”

Section: Radiogenic Argon In Morb and Oibmentioning

confidence: 99%

“…It was a great opportunity for our laboratory that Philippe Sarda was on-board. By itself, this sample has been the subject of a large number of publications and it is often considered as a reference sample for the study of noble gases in the mantle (Staudacher et al, 1989;Sarda and Graham, 1990;Javoy and Pineau, 1991;Burnard et al, 1997;Kunz et al, 1998;Kunz, 1999).…”

Section: Radiogenic Argon In Morb and Oibmentioning

confidence: 99%

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Noble gas constraints on the origin and evolution of Earth’s volatiles

Moreira¹

2013

GeochemPersp

118

164

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Section: Radiogenic Argon In Morb and Oibsupporting

confidence: 67%

Section: Radiogenic Argon In Morb and Oibmentioning

confidence: 99%

Section: Radiogenic Argon In Morb and Oibmentioning

confidence: 99%

See 1 more Smart Citation

Noble gas constraints on the origin and evolution of Earth’s volatiles

Moreira¹

2013

GeochemPersp

118

164

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“…4 pheric contamination, because the ratio is generally much higher (>1000) than the atmospheric value of 0.32 in samples derived from deep interior of the earth such as volcanic gases (e.g., Kusakabe et al, 2009), natural gases in old continents (e.g., Ballentine and Sherwood Lollar, 2002;Cornides et al, 1986;Ballentine et al, 1991;Kotarba and Nagao, 2008, and see references therein), glassy basalts from mid oceanic ridges (e.g., Staudacher et al, 1989), and mantle xenoliths (e.g., Nagao and Takahashi, 1993). 40 Ar/ 36 Ar ratio is also seriously affected by addition of atmospheric Ar with 40 Ar/ 36 Ar = 296 because air contains high concentration of Ar (~1%).…”

Section: Isotopic Ratios Ofmentioning

confidence: 99%

Noble gases in Lakes Nyos and Monoun, Cameroon

et al. 2010

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He, Ne and Ar isotopic ratios and concentrations of noble gases in different depths of Lakes Nyos and Monoun in Cameroon, West Africa, were investigated. Samples were collected in November 1999, January 2001 and December 2001. Improved sampling method applied in 2001 enabled us to detect detailed isotopic distribution in the lakes. Concentrations of Ne and Xe in the lake waters were low by factors of ~10 and ~3, respectively, compared with those of air saturated water (ASW), whereas in CO 2 gas they were depleted by 2 orders of magnitude compared with those in air. In contrast, He was strongly enriched in lake water by more than three orders of magnitude compared to ASW.3 He/ 4 He ratios of 8 × 10 -6 (Lake Nyos) and 5 × 10 -6 (Lake Monoun) indicated recharge of magmatic gases of mantle origin to the lakes, though the ratios were lowered by the addition of radiogenic 4 He from crustal rocks. A small contribution (<2%) of MORB-like Ne was detected in both lake waters. A simple mixing between two end members, i.e., atmosphere and gases from a deepseated reservoir, can explain the noble gas signatures. Depth profile of He concentration in Lake Nyos showed a clear layered structure with a maximum at 190 m, 20 m above the lake bottom. Below this depth, 3 He/ 4 He ratio decreased slightly, suggesting that the fluid from the deep-seated reservoir is supplied to the lake mainly at ca. 190 m. C/ 3 He ratios were 1.5 × 10 10 and 0.6 × 10 10 in deep and shallow layers of Lake Nyos, respectively. The C/ 3 He ratio was 1.7 × 10 10 at Lake Monoun. A gas recharge model to explain the observed layered structure in Lake Nyos is presented.

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“…Adsorbed gas component is presumed from noble gas abundance ratios of sediments (e.g., Matsuda and Nagao, 1986;Staudacher and Allegre, 1988). MORBs and island arc magmas (New Zealand) are plotted for reference (Hiyagon et al, 1992;Patterson et al, 1994;Staudacher et al, 1989). between them, crushing effect might attribute to the difference of 40Ar/36Ar between the medium grained and fine-grained samples.…”

Section: Ar Isotope Ratiosmentioning

confidence: 99%

Magmatic processes revealed by noble gas signatures: the case of Unzen Volcano, Japan.

Hanyu

Kaneoka

1997

Geochem. J.

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The usefulness of noble gas isotope systematics for understanding the volcanic systems is demonstrated in the case of Unzen Volcano, Japan. Noble gas concentrations and Ar isotope ratios were determined for coexisting plagioclase, hornblende and biotite in two dacitic volcanic rocks. Different species of minerals coexisting in a magma show different 40Ar/36Ar, and the 40Ar/36Ar is correlated to the grain sizes of the phenocrysts, indicating that they had crystallized in an evolving system of the magma. The variation of 40Ar/36Ar observed among samples can be explained by a two -component mixing: magmatic Ar and atmosphere-derived Ar. In order to explain the variation of 40Ar/36Ar, we propose a magmatic model in which the 40Ar/36Ar of magma had gradually decreased due to addition of atmosphere-derived Ar and, in the same sequence of time, phenocrysts had crystallized one after another as cooling of the magma had proceeded. Groundwater is the most probable candidate as carrier of atmosphere-derived Ar although crustal contamination is not completely excluded.

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Noble gases in basalt glasses from a Mid-Atlantic Ridge topographic high at 14°N: geodynamic consequences

Cited by 249 publications

References 50 publications

Noble gas constraints on the origin and evolution of Earth’s volatiles

Noble gas constraints on the origin and evolution of Earth’s volatiles

Noble gases in Lakes Nyos and Monoun, Cameroon

Magmatic processes revealed by noble gas signatures: the case of Unzen Volcano, Japan.

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