Novel insights into the degassing history of Earth's mantle from high precision noble gas analysis of magmatic gas

Bekaert, David V.; Broadley, Michael W.; Caracausi, Antonio; Marty, Bernard

doi:10.1016/j.epsl.2019.115766

Cited by 31 publications

(32 citation statements)

References 47 publications

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“…In Fig. 5, we show that the Yellowstone mantle source exhibits different 129 Xe/ 124,126,128 Xe ratios from that measured in MORB-derived samples (16)(17)(18). Although the difference is slight, the Brimstone Basin sample 4B has lower 129 Xe/ 124,126,128 Xe ratios than any previously measured MORB-derived sample.…”

mentioning

confidence: 64%

“…Krypton and xenon in the mantle are dominated by recycled atmosphere (16), rendering any evidence of accretionary signatures difficult to resolve. In order to circumvent this issue, large quantities of magmatic gas have been previously analyzed (6,16,17) to determine the primordial Kr and Xe signature of the mantle. Furthermore, a new protocol has been developed to accumulate mantle noble gases from highly vesicular basaltic MORB glass samples (18), which has enabled for the first time the primordial Kr and Xe signature from basaltic glass samples to be determined.…”

Section: Significancementioning

confidence: 99%

“…Recent attempts to determine the primordial heavy noble gas signature of the deep mantle have therefore been focused on the analysis of Xe in magmatic gases from the Eifel volcanic area in Germany (21). However, a recent reevaluation of Xe isotopes in Eifel has called into question whether it can be considered to originate from a deep, undegassed mantle source (17). Indeed, there is no supporting He isotope evidence, as 3 He/ 4 He values (<6 R A , where R A = 1.39 × 10 −6 , the 3 He/ 4 He ratio of air) in Eifel gas samples are lower than canonical MORB (8 ± 1 R A ) values and Ne isotopes follow the same trajectory as the air-MORB mixing line (17).…”

Section: Significancementioning

confidence: 99%

“…However, a recent reevaluation of Xe isotopes in Eifel has called into question whether it can be considered to originate from a deep, undegassed mantle source (17). Indeed, there is no supporting He isotope evidence, as 3 He/ 4 He values (<6 R A , where R A = 1.39 × 10 −6 , the 3 He/ 4 He ratio of air) in Eifel gas samples are lower than canonical MORB (8 ± 1 R A ) values and Ne isotopes follow the same trajectory as the air-MORB mixing line (17). The accretionary origin of heavy noble gases (Kr and Xe) in the deep mantle is therefore yet to be satisfactorily resolved.…”

Section: Significancementioning

confidence: 99%

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Identification of chondritic krypton and xenon in Yellowstone gases and the timing of terrestrial volatile accretion

Broadley

Barry

Bekaert

et al. 2020

Proc. Natl. Acad. Sci. U.S.A.

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Identifying the origin of noble gases in Earth’s mantle can provide crucial constraints on the source and timing of volatile (C, N, H2O, noble gases, etc.) delivery to Earth. It remains unclear whether the early Earth was able to directly capture and retain volatiles throughout accretion or whether it accreted anhydrously and subsequently acquired volatiles through later additions of chondritic material. Here, we report high-precision noble gas isotopic data from volcanic gases emanating from, in and around, the Yellowstone caldera (Wyoming, United States). We show that the He and Ne isotopic and elemental signatures of the Yellowstone gas requires an input from an undegassed mantle plume. Coupled with the distinct ratio of129Xe to primordial Xe isotopes in Yellowstone compared with mid-ocean ridge basalt (MORB) samples, this confirms that the deep plume and shallow MORB mantles have remained distinct from one another for the majority of Earth’s history. Krypton and xenon isotopes in the Yellowstone mantle plume are found to be chondritic in origin, similar to the MORB source mantle. This is in contrast with the origin of neon in the mantle, which exhibits an isotopic dichotomy between solar plume and chondritic MORB mantle sources. The co-occurrence of solar and chondritic noble gases in the deep mantle is thought to reflect the heterogeneous nature of Earth’s volatile accretion during the lifetime of the protosolar nebula. It notably implies that the Earth was able to retain its chondritic volatiles since its earliest stages of accretion, and not only through late additions.

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confidence: 64%

Section: Significancementioning

confidence: 99%

Section: Significancementioning

confidence: 99%

Section: Significancementioning

confidence: 99%

See 2 more Smart Citations

Identification of chondritic krypton and xenon in Yellowstone gases and the timing of terrestrial volatile accretion

Broadley

Barry

Bekaert

et al. 2020

Proc. Natl. Acad. Sci. U.S.A.

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“…Recent high precision analyses of Ne, Ar, and Xe isotopes sampled in springs in the South East Eifel (Victoriaquelle and Schwefelquelle wells, Figure 2b, Table 1) indicate that the mantle beneath the Eifel volcanic area resembles more a convective upper mantle reservoir (MORB‐type) than a deep plume source (Bekaert et al, 2019). Ne and Xe systematics point toward contributions from multiple reservoirs with different degassing, supporting the interpretation of Bräuer et al (2013).…”

Section: Magmatic Systems Beneath the Rhm: State Of Knowledgementioning

confidence: 99%

Seismological and Geophysical Signatures of the Deep Crustal Magma Systems of the Cenozoic Volcanic Fields Beneath the Eifel, Germany

Dahm

Stiller

Mechie

et al. 2020

Geochem Geophys Geosyst

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The Quaternary volcanic fields of the Eifel (Rhineland‐Palatinate, Germany) had their last eruptions less than 13,000 years ago. Recently, deep low‐frequency (DLF) earthquakes were detected beneath one of the volcanic fields showing evidence of ongoing magmatic activity in the lower crust and upper mantle. In this work, seismic wide‐ and steep‐angle experiments from 1978/1979 and 1987/1988 are compiled, partially reprocessed and interpreted, together with other data to better determine the location, size, shape, and state of magmatic reservoirs in the Eifel region near the crust‐mantle boundary. We discuss seismic evidence for a low‐velocity gradient layer from 30–36 km depth, which has developed over a large region under all Quaternary volcanic fields of the Rhenish Massif and can be explained by the presence of partial melts. We show that the DLF earthquakes connect the postulated upper mantle reservoir with the upper crust at a depth of about 8 km, directly below one of the youngest phonolitic volcanic centers in the Eifel, where CO2 originating from the mantle is massively outgassing. A bright spot in the West Eifel between 6 and 10 km depth represents a Tertiary magma reservoir and is seen as a model for a differentiated reservoir beneath the young phonolitic center today. We find that the distribution of volcanic fields is controlled by the Variscan lithospheric structures and terrane boundaries as a whole, which is reflected by an offset of the Moho depth, a wedge‐shaped transparent zone in the lower crust and the system of thrusts over about 120 km length.

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Noble gas mass spectrometry

Broadley,

Bekaert

2025

Treatise on Geochemistry

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Novel insights into the degassing history of Earth's mantle from high precision noble gas analysis of magmatic gas

Cited by 31 publications

References 47 publications

Identification of chondritic krypton and xenon in Yellowstone gases and the timing of terrestrial volatile accretion

Identification of chondritic krypton and xenon in Yellowstone gases and the timing of terrestrial volatile accretion

Seismological and Geophysical Signatures of the Deep Crustal Magma Systems of the Cenozoic Volcanic Fields Beneath the Eifel, Germany

Noble gas mass spectrometry

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