Implanted sup 3 He, sup 4 He, and Xe in further studies of diamonds from Western Australia

Journal Article · Mon Jul 01 00:00:00 EDT 1991 · Geochimica et Cosmochimica Acta; (United States)

DOI:https://doi.org/10.1016/0016-7037(91)90037-6· OSTI ID:5904244

McConville, P; Reynolds, J H ^[1]; Epstein, S ^[2]; Roedder, E ^[3]

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1. Univ. of California, Berkeley (United States)
2. California Inst. of Tech., Pasadena (United States)
3. Harvard Univ., Cambridge, MA (United States)

In measurements of the noble gases in additional samples of diamonds from the Argyle and Ellendale lamproites in Western Australia the authors have failed to encounter any neon-rich stones such as showed solar-like isotopic compositions in earlier work. No neon was detected above the relatively high blank levels in their glass apparatus. White and brown diamonds showed no differences in noble gas content, nor did samples segregated by the color of long-wave UF fluorescence. The rare gas patterns in the 1.2 GTa Argyle pipe are largely consistent with implanted {sup 3}He, {sup 4}He, and fissiogenic Xe from U/Th in the matrix rock in which the diamonds have been stored for so long. These implanted species are absent in diamonds from the much younger ({approximately}20 Ma) Ellendale pipe. The authors give implantation formulae for several models of inhomogeneously distributed U/Th. Differences in {sup 3}He content between pipe and alluvial Argyle samples are consistent with expected cosmogenic production in the latter. An expanded data base for helium and carbon isotopic data on the same samples supports a negative ({sup 4}He)-{delta}{sup 13}C correlation seen earlier in work from their group, but if the Argyle samples, which contain light carbon, are corrected for implanted {sup 4}He, the correlation is considerably weakened. The authors no longer see an earlier {sup 3}He/{sup 4}He-{delta}{sup 13}C correlation.

• OSTI ID: 5904244
• Journal Information: Geochimica et Cosmochimica Acta; (United States), Vol. 55:7; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
DIAMONDS
CHEMICAL COMPOSITION
GEOCHEMISTRY
WESTERN AUSTRALIA
VOLCANIC ROCKS
COMPARATIVE EVALUATIONS
FLUORESCENCE SPECTROSCOPY
HELIUM
HELIUM 3
HELIUM 4
ISOTOPE RATIO
NEON
XENON
AUSTRALASIA
AUSTRALIA
CARBON
CHEMISTRY
DEVELOPED COUNTRIES
ELEMENTAL MINERALS
ELEMENTS
EMISSION SPECTROSCOPY
EVALUATION
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
FLUIDS
GASES
HELIUM ISOTOPES
IGNEOUS ROCKS
ISOTOPES
LIGHT NUCLEI
MINERALS
NONMETALS
NUCLEI
RARE GASES
ROCKS
SPECTROSCOPY
STABLE ISOTOPES
580000* - Geosciences