Terrestrial and Martian weathering signatures of xenon components in shergottite mineral separates

Cartwright, J. A.; Ocker, K. D.; Crowther, S A; Burgess, R.; Gilmour, J. D.

doi:10.1111/j.1945-5100.2010.01101.x

Cited by 6 publications

(6 citation statements)

References 61 publications

(208 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our RBT 04261 data compare well with the extensive data set of Cartwright et al. () who measured mineral separates, i.e., six olivine‐pyroxene mixtures (ol‐pyx), two maskelynite separates (mask), and one opaques separate (Fig. ).…”

Section: Resultssupporting

confidence: 84%

“…Moreover, two trends are visible in our data set. This was observed before for RBT 04261 by Cartwright et al (), who studied mineral separates and therefore could assign the high K and Martian atmosphere contribution to maskelynite, whereas a high 38 Ar/ 36 Ar, interpreted as chlorine, was found in the olivine‐pyroxene fraction. The data set presented here (Fig.…”

Section: Discussionsupporting

confidence: 72%

“…Plot of the isotopic ratios 129 Xe/ 132 Xe and 136 Xe/ 132 Xe versus the elemental ratio of 84 Kr/ 132 Xe of RBT 04261 (this study) and mineral separate stepwise heating experiments of Cartwright et al (). Note the high 129 Xe/ 132 Xe (Martian atmosphere) in the maskelynite separates (mask), which points at the source for the Martian atmospheric component in the 1000 °C measurement of our bulk rocks.…”

Section: Resultsmentioning

confidence: 57%

See 2 more Smart Citations

Quantifying noble gas contamination during terrestrial alteration in Martian meteorites from Antarctica

Schwenzer

Greenwood

Kelley

et al. 2013

Meteorit & Planetary Scien

View full text Add to dashboard Cite

Abstract-We investigated exterior and interior subsamples from the Martian shergottite meteorites Allan Hills (ALH) A77005 and Roberts Massif (RBT) 04261 for secondary minerals, oxygen isotopes, Ar-Ar, and noble gas signatures. Electron microprobe investigations revealed that RBT 04261 does not contain any visible alteration even in its most exterior fractures, whereas fracture fillings in ALHA77005 penetrate into the meteorite up to 300 lm, beyond which the fractures are devoid of secondary minerals. Light noble gases seem to be almost unaffected by terrestrially induced alteration in both meteorites. Thus, a shock metamorphic overprint of 30-35 GPa can be deduced from the helium measurements in RBT 04261. Oxygen isotopes also seem unaffected by terrestrially weathering and variations can easily be reconciled with the differences in modal mineralogy of the exterior and interior subsamples. The measurements on irradiated samples (Ar-Ar) showed a clear Martian atmospheric contribution in ALHA77005, but this is less apparent in our sample of RBT 04261. Exterior and interior subsamples show slight differences in apparent ages, but the overall results are very similar between the two. In contrast, krypton and xenon are severely affected by terrestrial contamination, demonstrating the ubiquitous presence of elementally fractionated air in RBT 04261. Although seemingly contradictory, our results indicate that RBT 04261 was more affected by contamination than ALHA77005. We conclude that irrespective of on which planet the alteration occurred, exposure of Martian rocks to atmosphere (or brine) introduces noble gases with signatures elementally fractionated relative to the respective atmospheric composition into the rock, and relationships of that process with oxygen isotopes or mineralogical observations are not straightforward.

show abstract

Section: Resultssupporting

confidence: 84%

Section: Discussionsupporting

confidence: 72%

Section: Resultsmentioning

confidence: 57%

See 1 more Smart Citation

Quantifying noble gas contamination during terrestrial alteration in Martian meteorites from Antarctica

Schwenzer

Greenwood

Kelley

et al. 2013

Meteorit & Planetary Scien

View full text Add to dashboard Cite

show abstract

“…Observing these effects on a fall meteorite emphasizes the importance of this matter. Isotopic changes caused by meteorite weathering are also reported in H (Stephant et al, 2018), O (Stelzner and Heide, 1996), noble gases (Cartwright et al, 2010;Kaneoka, 1983;Schultz et al, 2005), Sr (Borg et al, 2016(Borg et al, , 2003Brandon et al, 2004;Elardo et al, 2014;Shih et al, 2007), Hf (Sokol et al, 2008;Tatsumoto et al, 1981), Os (Borg et al, 2003;Brandon et al, 2012), Fe (Saunier et al, 2010), U-and Th-series as well as Cs (Weber et al, 2017), and Pb (Tatsumoto et al, 1981) isotopes.…”

Section: J O U R N a L P R E -P R O O Fmentioning

confidence: 92%

The effects of terrestrial weathering on samarium‑neodymium isotopic composition of ordinary chondrites

et al. 2021

View full text Add to dashboard Cite

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. 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.

show abstract

“…All martian meteorites show evidence of shock metamorphism, resulting from the large-scale impacts that ejected them from the surface of Mars (Nyquist et al 2001). Shock implantation of martian atmospheric gases into meteorites (Ocker and Gilmour 2004;Cartwright et al 2010) occurred with shock pressures ranging from 15 to 45 GPa (Fritz et al 2005). This is evidenced particularly in 129 Xe/ 132 Xe ratios that exceed that of solar (1.0450 ±0.0050;Crowther and Gilmour 2013) or the trapped 'planetary' component Q-Xe (1.042 ±0.002;Busemann et al 2000) preserved in glass, opaque mineral phases, maskelyinite and pyroxene in martian meteorites (Ocker and Gilmour 2004;Cartwright et al 2010).…”

Section: Secondary Alteration Assemblagesmentioning

confidence: 99%

Heavy halogen geochemistry of martian shergottite meteorites and implications for the halogen composition of the depleted shergottite mantle source

Clay

Joy

O’Driscoll

et al. 2020

American Mineralogist

View full text Add to dashboard Cite

Volatile elements (e.g., H, C, N) have a strong influence on the physical and chemical evolution of planets and are essential for the development of habitable conditions. Measurement of the volatile and incompatible heavy halogens, Cl, Br, and I, can provide insight into volatile distribution and transport processes, due to their hydrophilic nature. However, information on the bulk halogen composition of martian meteorites is limited, particularly for Br and I, largely due to the difficulty in measuring ppb-level Br and I abundances in small samples. In this study, we address this challenge by using the neutron irradiation noble gas mass spectrometry (NI-NGMS) method to measure the heavy halogen composition of five olivine-phyric shergottite meteorites, including the enriched (Larkman Nunatak LAR 06319 and LAR 12011) and depleted (LAR 12095, LAR 12240, and Tissint) compositional end-members. Distinct differences in the absolute abundances and halogen ratios exist between enriched (74 to136 ppm Cl, 1303 to 3061 ppb Br, and 4 to 1423 ppb I) and depleted (10 to 26 ppm Cl, 46 to 136 ppb Br, and 3 to 329 ppb I) samples. All halogen measurements are within the ranges previously reported for martian shergottite, nakhlite, and chassignite (SNC) meteorites. Enriched shergottites show variable and generally high Br and I absolute abundances. Halogen ratios (Br/Cl and I/Cl) are in proportions that exceed those of both carbonaceous chondrites and the martian surface. This may be linked to a volatile-rich martian mantle source, be related to shock processes or could represent a small degree of heavy halogen contamination (a feature of some Antarctic meteorites, for example). The differences observed in halogen abundances and ratios between enriched and depleted compositions, however, are consistent with previous suggestions of a heterogeneous distribution of volatiles in the martian mantle. Depleted shergottites have lower halogen abundances and Br and Cl in similar proportions to bulk silicate Earth and carbonaceous chondrites. Tissint in particular, as an uncontaminated fall, allows an estimate of the depleted shergottite mantle source composition to be made: 1.2 ppm Cl, 7.0 ppb Br, and 0.2 ppb I. The resultant bulk silicate Mars (BSM) estimate (22 ppm Cl, 74 ppb Br, and 6 ppb I), including the martian crust and depleted shergottite mantle, is similar to estimates of the bulk silicate earth (BSE) halogen composition.

show abstract

Terrestrial and Martian weathering signatures of xenon components in shergottite mineral separates

Abstract: Abstract-Xenon-isotopic ratios, step-heating release patterns, and gas concentrations of mineral separates from Martian shergottites Roberts Massif (RBT) 04262, Dar al Gani (DaG) 489, Shergotty, and Elephant Moraine (EET) 79001 lithology B

Cited by 6 publications

References 61 publications

Quantifying noble gas contamination during terrestrial alteration in Martian meteorites from Antarctica

Quantifying noble gas contamination during terrestrial alteration in Martian meteorites from Antarctica

The effects of terrestrial weathering on samarium‑neodymium isotopic composition of ordinary chondrites

Heavy halogen geochemistry of martian shergottite meteorites and implications for the halogen composition of the depleted shergottite mantle source

Contact Info

Product

Resources

About