Light hydrocarbon gases, C13, and origin of organic matter in carbonaceous chondrites

Belsky, T.; Kaplan, I. R.

doi:10.1016/0016-7037(70)90105-5

Cited by 71 publications

(24 citation statements)

References 25 publications

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“…These data suggest that effective blank production is reduced when rock fragments are present in the ball mill and that repeated shaking in the presence of rock powder results in less blank production. A similar observation by Belsky and Kaplan (1970), in which gas amounts decreased with repeated crushing of previously crushed material, was interpreted by them as an indication that the released gases were indigenous to the rock and not produced by impact within the crushing device. Such an effect may be due t o a reduction in med-metal impact within the crusher, possibly because of cushioning by the rock powder, so that blank generation is reduced compared with the-empty ball-mill runs.…”

Section: Blank Productionmentioning

confidence: 63%

Methane and hydrogen in mid-ocean-ridge basalt glasses: analysis by vacuum crushing

Welhan¹

1988

Can. J. Earth Sci.

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A comparative study of vacuum crushing methods for analyzing reactive gases in basaltic glasses shows that ball milling is an efficient means of releasing occluded gases but that blank production represents a potentially serious problem that must be accounted for when determining reactive-gas compositions. Production of Hz and CH, in a stainless-steel ball mill in the absence of rock material increases with length of crushing time. However, test results presented here indicate that blank levels are reduced during the actual crushing process by the presence of rock powder, which may act as a cushion to reduce metal-metal contact. Crushing in copper tubes under a hydraulic press produces no blanks for these gases, but crushing efficiency and gas release are very low, and gas adsorption on rock powder becomes a significant problem. Experiments with methane adsorption on crushed basalt suggest that the loss of methane is a chemisorption process that is, for the most part, irreversible.Applying corrections for these effects, we find that H,/CH, ratios ( -3 -30) in mid-ocean-ridge basalt glasses are similar to those seen in high-temperature mid-ocean-ridge hydrothermal fluids. These data, arguments based on the similarity of waterlrock mass ratios calculated from basalt gas data, and the uniformity of methanelhelium ratios in divers high-temperature mid-ocean-ridge hydrothermal fluids support the contention that dissolved CH, and H, in these fluids are predominantly derived from leaching of mid-ocean-ridge basalt.Une Ctude comparative des mCthodes de broyage sous vide servant h analyser les gaz kactifs dans les verres basaltiques rCvkle que le broyage i boulets constitue un moyen efficace de rellchement des gaz d'occlusion mais que cette production de vides reprksente de strieux problkmes potentiels dont il faut tenir compte dans la dktermination des compositions des gaz kactifs. La production de Hz et de CH, dans un broyeur i boulets en acier inoxydable, en absence de matCriaux rocheux, augmente avec le temps de broyage. Cependant, les ksutats des essais prCsentCs ici indiquent que les quantitCs de vides sont kduits durant le traitement de broyage actuel par la pksence de poudre de roche, laquelle peut servir de coussins et diminuer le contact mCtal-mCtal. Le broyage dans des tubes de cuivre sous une presse hydraulique ne produit pas de vides pour ces gaz, cependant I'efficacitC du broyage et le reldchement des gaz sont trks faibles, et l'adsorption des gaz sur la poudre de roche devient un problkme sCrieux. Des essais d'adsorption de mtthane sur du basalte broyC kvklent que la perte de methane est un processus de chimiosorption qui, de manikre gCnCrale, est idversible.Ap&s application de corrections pour ces effets, les rapports de H,/CH, (environ 3-30) dans les verres des basaltes de cktes mCdiooctaniques apparaissent analogues i ceux observks dans les fluides hydrothermaux de cr6tes medio-ocCaniques de tempCrature ClevCe. Ces ksultats, les arguements fond& sur la similitude de rapports des masses eaulroches, calcul...

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Section: Blank Productionmentioning

confidence: 63%

Methane and hydrogen in mid-ocean-ridge basalt glasses: analysis by vacuum crushing

Welhan¹

1988

Can. J. Earth Sci.

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“…The abundance and stable C-isotopic composition of bulk C within the stony meteorites is well characterised (e.g., Otting and Zahringer, 1967;Belsky and Kaplan, 1970;Smith and Kaplan, 1970;…”

Section: Discussionmentioning

confidence: 99%

The content and stable isotopic composition of carbon in individual micrometeorites from Greenland and Antarctica

Wright

Yates²,

Hutchison

et al. 1997

Meteorit & Planetary Scien

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Abstract-The C contents and d13C values of eleven individual micrometeorites have been determined using a combination of stepped combustion and static mass spectrometry. A new low-blank procedure, involving pretreatment of the samples with a solvent to remove surficial contaminants, has enabled samples of 6 8 4 ,ug to be analysed successfully. The eleven samples (seven separated from Greenland cryciconite and four from Antarctic ice) were each split prior to C determination and a fragment taken for study using analytical electron microscopy. In this way, the chemical compositions were obtained thereby allowing comparison with other investigations. As with previous studies of micrometeorites collected at the Earth's surface, the major difficulty with interpreting the results involves distinguishing indigenous components from terrestrial contaminants. Overall C contents were typically

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“…These studies detected a large number of aromatic and alkyl aromatic compounds ranging from naphthalene to coronene and, in many Table 11 Carbon and hydrogen isotope data for individual volatile alkanes (Butterworth et al, 2004;Yuen et al, 1984) and normal alkanes (Sephton et al, 2001a) cases, high-molecular-weight compounds dominated. Aromatic hydrocarbons can be liberated by heating meteorites at temperatures at or below 300 C. Such thermally extracted compounds, ranging from benzene to pyrene, were detected by mass spectrometry (Hayes and Biemann, 1968;Muenow et al, 1971;Studier et al, 1965Studier et al, , 1968; GC (Belsky and Kaplan, 1970;Levy et al, 1970) and GC-MS . The analyses of Allende (CV3) shortly after its fall revealed small amounts of aromatic contamination, which consisted mainly of a phenyl alkane structure.…”

Section: Solvent and Thermal Extractsmentioning

confidence: 99%

Organic Geochemistry of Meteorites

Sephton¹

2014

Treatise on Geochemistry

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Light hydrocarbon gases, C13, and origin of organic matter in carbonaceous chondrites

Cited by 71 publications

References 25 publications

Methane and hydrogen in mid-ocean-ridge basalt glasses: analysis by vacuum crushing

Methane and hydrogen in mid-ocean-ridge basalt glasses: analysis by vacuum crushing

The content and stable isotopic composition of carbon in individual micrometeorites from Greenland and Antarctica

Organic Geochemistry of Meteorites

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