Hydrogen isotope composition of insoluble organic matter from cherts

Journal Article · Wed Feb 01 00:00:00 EST 1989 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(89)90396-7· OSTI ID:5062163

Robert, F ^[1]

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1. California Institute of Technology, Pasadena (USA)

No systematic variation is seen in the D/H ratio of insoluble organic matter present in cherts that were deposited over the last 3.5. B.y. Hydrogen isotope exchange experiments between deuterium-rich acid solutions and acid residues extracted from cherts show that hydrogen, extracted after the chert was outgassed at 350{degree}C, is not affected by the contamination from the chemical treatment of the samples. In two modern cherts (Eocene and Pliocene) having exceptionally low {delta}{sup 18}O values and high carbon contents, hydrogen extracted by pyrolysis at low temperature (200-350{degree}C) is markedly enriched in deuterium ({delta}D values up to +500{per thousand}). Such an enrichment is ascribed to organic products derived from the maturation of kerogen. Provided this hydrogen isotope fractionation is not related to biological activity, a similar effect could have played a role in the maturation of the deuterium-rich organic matter found in the carbonaceous meteorites during an early hydrothermal event.

• OSTI ID: 5062163
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Vol. 53:2; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
58 GEOSCIENCES
CHERT
GEOCHEMISTRY
KEROGEN
ISOTOPIC EXCHANGE
MATURATION
CARBONACEOUS MATERIALS
HYDROGEN ISOTOPES
ISOTOPE RATIO
METEORITES
OXYGEN 18
PRECAMBRIAN ERA
QUANTITATIVE CHEMICAL ANALYSIS
TERTIARY PERIOD
BITUMINOUS MATERIALS
CENOZOIC ERA
CHEMICAL ANALYSIS
CHEMISTRY
EVEN-EVEN NUCLEI
GEOLOGIC AGES
ISOTOPES
LIGHT NUCLEI
MATERIALS
NUCLEI
ORGANIC MATTER
OXYGEN ISOTOPES
ROCKS
SEDIMENTARY ROCKS
STABLE ISOTOPES
400202* - Isotope Effects
Isotope Exchange
& Isotope Separation
580000 - Geosciences