Nature of volatile depletion and genetic relationships in enstatite chondrites and aubrites inferred from Zn isotopes

Moynier, Frédéric; Paniello, Randal C.; Gounelle, M.; Albarède, Francis; Beck, Pierre; Podosek, F. A.; Zanda, B.

doi:10.1016/j.gca.2010.09.022

Cited by 92 publications

(63 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All data plot on the mass-dependent fractionation line of slope 1.978 (R 2 = 0.9993) on the three-isotope plot. All of the non-Antarctic HED d 66 Zn values lie within 0 ± 2&, The HED subgroup ranges overlap significantly: non-Antarctic Cloquet et al, 2008, and this study); while the range for enstatite meteorites is very broad, from À7.08& for aubrites to +7.35& for EL chondrites (Paniello et al, 2009;Moynier et al, 2011). Nevertheless, with d 66 Zn = À7.75&, PCA 82502 lies outside this range as the most extreme Zn fractionation reported to date.…”

Section: Resultssupporting

confidence: 56%

“…They also concluded that the primary volatile element depletion of the inner solar system did not involve kinetic Rayleigh evaporation or condensation. Moynier et al (2011) also reported Zn depletion without fractionation in enstatite chondrites and aubrites, again concluding that the findings were not due to evaporative/condensation processes. It is possible that Vesta's original depletion in Zn may have also been nonevaporative, but the heavy unbrecciated Antarctic samples support a mass-dependent fractionation process such as volatization.…”

Section: Chondritic Origin For Vesta and The Origin Of The Elemental mentioning

confidence: 73%

See 1 more Smart Citation

Zinc isotopes in HEDs: Clues to the formation of 4-Vesta, and the unique composition of Pecora Escarpment 82502

Paniello¹,

Moynier²,

Beck

et al. 2012

Geochimica et Cosmochimica Acta

Self Cite

View full text Add to dashboard Cite

The d 66 Zn (permil deviation of the 66 Zn/ 64 Zn ratio from a terrestrial standard) values for a suite of 20 non-Antarctic HED (howardite-eucrite-diogenite) meteorites and one mesosiderite, and for eight Antarctic eucrites and diogenites, were measured in order to determine the role of volatization in the formation of their presumed parent body, the asteroid 4-Vesta. The 20 non-Antarctic HEDs had d 66 Zn values that ranged from À2.0& to +1.67&, with a mean value of À0.01 ± 0.39& (2 se); this range likely represents a small-scale heterogeneity due to brecciation induced by multiple impacts. The non-Antarctic eucrites (d 66 Zn = +0.00 ± 0.58& (2 se), n = 12) were isotopically the same as the diogenites (d 66 Zn = À0.31 ± 0.80& (2 se), n = 4), and the howardites (d 66 Zn = +0.26 ± 0.37& (2 se), n = 4). On average, non-Antarctic eucrite falls were isotopically heavier (+0.50&) than non-Antarctic finds (À1.00&). The Antarctic finds studied were all unbrecciated samples, and they were significantly heavier than the non-Antarctic samples with a d 66 Zn range of +1.63& to +6.22& for four eucrites (mean, +4.32&) and +0.94& to +1.60& for three diogenites (mean + 1.23&), excluding one anomalous sample, while their Zn concentration is significantly lower than the brecciated samples. These data suggest that the unbrecciated eucrites probably represent the eucritic crust shortly after differentiation and cooling of the parent asteroid, at which time volatization of lighter zinc isotopes led to an isotopically heavy crust. Early impact events caused the ejection of these unbrecciated meteorites, which were subsequently spared from brecciation caused by multiple additional impacts on the much larger Vesta. The range of d 66 Zn values and Zn concentration for the brecciated HEDs in this study supports a major contribution to the Vestan surface by chondritic impactors (À1.30 < d 66 Zn < +0.76& for ordinary and carbonaceous chondrites). The anomalous eucrite PCA 82502 (d 66 Zn = À7.75&) is significantly isotopically lighter than the other HEDs and is the natural sample with the lightest Zn isotopic composition reported in the solar system to date. This meteorite most likely originated from a distinct parent body.

show abstract

Section: Resultssupporting

confidence: 56%

Section: Chondritic Origin For Vesta and The Origin Of The Elemental mentioning

confidence: 73%

Zinc isotopes in HEDs: Clues to the formation of 4-Vesta, and the unique composition of Pecora Escarpment 82502

Paniello¹,

Moynier²,

Beck

et al. 2012

Geochimica et Cosmochimica Acta

Self Cite

View full text Add to dashboard Cite

show abstract

“…It experienced a complex history and almost certainly formed on a separate parent body to that of the main-group aubrites (Keil et al, 1989;Rubin, 2015); an interpretation that is in agreement with Hf-W systematics (Petitat et al, 2008) and Zn isotopes (Moynier et al, 2011). In addition to these aubritic samples, a few other enstatite achondrites are known, such as Itqiy and Northwest Africa 2526.…”

Section: Introductionmentioning

confidence: 54%

The origin of aubrites: Evidence from lithophile trace element abundances and oxygen isotope compositions

Barrat

Greenwood

Keil

et al. 2016

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

Please cite this article as: Barrat, J.A., Greenwood, R.C., Keil, K., Rouget, M.L., Boesenberg, J.S., Zanda, B., Franchi, I.A., The origin of aubrites: Evidence from lithophile trace element abundances and oxygen isotope compositions, Geochimica et Cosmochimica Acta (2016), doi: http://dx.doi.org/10. 1016/j.gca.2016.07.025 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Leaching experiments were undertaken to investigate the contribution of sulfides to the whole rock 3

show abstract

“…Enstatite chondrites, which are more reduced than ordinary or carbonaceous chondrites, show a trend of increasing δ 66 Zn with decreasing Zn abundance, and are consistent with evaporative fractionation [73]. With more reducing conditions from carbonaceous to enstatite chondrites, Zn can be preferentially partitioned into sulfides (or chlorides) relative to silicates [35,73]. On reduced bodies, such as the Moon, desulfidation and dechlorination will also lead to pronounced Zn loss and Zn isotopic fractionation.…”

Section: (B) Volatile Loss During the Earth-moon Forming Giant Impact?mentioning

confidence: 70%

Evaporative fractionation of volatile stable isotopes and their bearing on the origin of the Moon

Day

Moynier

2014

Phil. Trans. R. Soc. A.

109

View full text Add to dashboard Cite

The Moon is depleted in volatile elements relative to the Earth and Mars. Low abundances of volatile elements, fractionated stable isotope ratios of S, Cl, K and Zn, high μ ( 238 U/ 204 Pb) and long-term Rb/Sr depletion are distinguishing features of the Moon, relative to the Earth. These geochemical characteristics indicate both inheritance of volatile-depleted materials that formed the Moon and planets and subsequent evaporative loss of volatile elements that occurred during lunar formation and differentiation. Models of volatile loss through localized eruptive degassing are not consistent with the available S, Cl, Zn and K isotopes and abundance data for the Moon. The most probable cause of volatile depletion is global-scale evaporation resulting from a giant impact or a magma ocean phase where inefficient volatile loss during magmatic convection led to the present distribution of volatile elements within mantle and crustal reservoirs. Problems exist for models of planetary volatile depletion following giant impact. Most critically, in this model, the volatile loss requires preferential delivery and retention of late-accreted volatiles to the Earth compared with the Moon. Different proportions of late-accreted mass are computed to explain present-day distributions of volatile and moderately volatile elements (e.g. Pb, Zn; 5 to >10%) relative to highly siderophile elements (approx. 0.5%) for the Earth. Models of early magma ocean phases may be more effective in explaining the volatile loss. Basaltic materials (e.g. eucrites and angrites) from highly differentiated airless asteroids are volatile-depleted, like the Moon, whereas the Earth and Mars have proportionally greater volatile contents. Parent-body size and the existence of early atmospheres are therefore likely to represent fundamental controls on planetary volatile retention or loss.

show abstract

Nature of volatile depletion and genetic relationships in enstatite chondrites and aubrites inferred from Zn isotopes

Cited by 92 publications

References 52 publications

Zinc isotopes in HEDs: Clues to the formation of 4-Vesta, and the unique composition of Pecora Escarpment 82502

Zinc isotopes in HEDs: Clues to the formation of 4-Vesta, and the unique composition of Pecora Escarpment 82502

The origin of aubrites: Evidence from lithophile trace element abundances and oxygen isotope compositions

Evaporative fractionation of volatile stable isotopes and their bearing on the origin of the Moon

Contact Info

Product

Resources

About