GEOCHEMICAL JOURNAL

Wollastonite whiskers in the Allende meteorite and their bearing on a possible post-condensation process

Masamichi Miyamoto, Naoki Onuma, Hiroshi Takeda

1979 Volume 13 Issue 1 Pages 1-5
Published: 1979
Released on J-STAGE: April 08, 2008

DOIhttps://doi.org/10.2343/geochemj.13.1

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The fine-grained white inclusions in the Allende meteorite have been studied by the scanning electron microscope with non-dispersive and dispersive X-ray detector, and a transmission electron microscope. The white inclusions consist almost entirely of the aggregates of losely packed semi-euhedral crystals rich in Ca and Al on the whole. Whisker crystals 0.5-5 microns in width and 10-50 microns long are found in cavities about 0.1 mm in diameter. These whisker crystals are wollastonite (CaSiO₃) whose formation process has not been fully elucidated with the equilibrium condensation. On the basis of the evidence that a portion of the wall of the wollastonite-filled cavity is rich in Al₂O₃, we presumed some possible formation processes of these wollastonite whiskers. In conjunction with a finding of layered rims enclosing Ca-Al rich inclusions in carbonaceous chondrites, the growth of wollastonite whiskers in the inclusions also provide an evidence that some post-condensation processes took place within the inclusions as well as at the rims.

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Eigenvector space display of lanthanoid data, an alternative to MASUDA-CORYELL Plots

Olav H. J. Christie

1979 Volume 13 Issue 1 Pages 7-10
Published: 1979
Released on J-STAGE: September 26, 2008

DOIhttps://doi.org/10.2343/geochemj.13.7

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Plots in two- or three-dimensional eigenvector spaces of lanthanoid data are suggested as an alternative to MASUDA-CORYELL plots of normalized data.

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Geochemical behaviour of lanthanoid elements in some clays and bauxite

Olav H. J. Christie, Elen Roaldset

1979 Volume 13 Issue 1 Pages 11-14
Published: 1979
Released on J-STAGE: April 08, 2008

DOIhttps://doi.org/10.2343/geochemj.13.11

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Semiquantitative eigenvector analysis demonstrates that differentiation of individual lanthanoids occurs in sedimentary environments. By means of eigenvector diagrams the degree of lanthanoid fractionation can be expressed semi-quantitatively.

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Excess crustal calcium problem

Ricardo M. Pytkowicz

1979 Volume 13 Issue 1 Pages 15-17
Published: 1979
Released on J-STAGE: April 08, 2008

DOIhttps://doi.org/10.2343/geochemj.13.15

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RONOV and YAROSHEVSKY (1969) observed the abnormally high calcium content of the earth crust and LOWENGART (1975) explained it as resulting from exchange between oceanic magnesium and mantle calcium. An alternate explanation is presented, namely, that the excess calcium results from the conversion of plagioclase feldspars into carbonates.

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Lanthanide tetrad effect observed in marine environment

Akimasa Masuda, Yoshihiro Ikeuchi

1979 Volume 13 Issue 1 Pages 19-22
Published: 1979
Released on J-STAGE: April 08, 2008

DOIhttps://doi.org/10.2343/geochemj.13.19

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We have found that lanthanide tetrad effect (PEPPARD et al., 1969) is operative for heavy rare-earth elements (REE) in a phosphorite sample (GOLDBERG et al., 1963). Also it has been evinced that the similar effect is observed for REE in sea waters. However, in the case where the plot (Masuda-Coryell plot) is void of the points for Tb, Ho and Tm, the resultant joint-line pattern is to have the common characteristics that the zigzag pattern is pointed downward at Dy and Yb and upward at Er. That is, the zigzag pattern with phase coincidence in breaking and its direction is a partially cut-off reflection of lanthanide tetrad effect. Employing the stable isotope dilution technique, we could determine REE in one-liter sample of sea water, with errors less than 2∼3%.

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A general solution for the puzzle of the xenon

P. K. Kuroda

1979 Volume 13 Issue 1 Pages 23-25
Published: 1979
Released on J-STAGE: April 08, 2008

DOIhttps://doi.org/10.2343/geochemj.13.23

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Rb-Sr whole rock dating of acid rocks

N. H. Gale, R. D. Beckinsale, A. J. Wadge

1979 Volume 13 Issue 1 Pages 27-29
Published: 1979
Released on J-STAGE: April 08, 2008

DOIhttps://doi.org/10.2343/geochemj.13.27

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Comments on paper by W. L. RAINES, T. M. FLANDERS and P. K. KURODA “Superheavy elements in nature?: Fissiogenic xenon in Sudbury, Ontario, norite”

W. Rison, S. Niemeyer

1979 Volume 13 Issue 1 Pages 31-33
Published: 1979
Released on J-STAGE: April 08, 2008

DOIhttps://doi.org/10.2343/geochemj.13.31

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Reply to the comments by RISON and NIEMEYER

P. K. Kuroda

1979 Volume 13 Issue 1 Pages 35-36
Published: 1979
Released on J-STAGE: April 08, 2008

DOIhttps://doi.org/10.2343/geochemj.13.35

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Magnetite heterogeneity among Cl chondrites

M. Hyman, M. W. Rowe, J. M. Herndon

1979 Volume 13 Issue 1 Pages 37-39
Published: 1979
Released on J-STAGE: April 08, 2008

DOIhttps://doi.org/10.2343/geochemj.13.37

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ERRATUM

1979 Volume 13 Issue 1 Pages e1
Published: 1979
Released on J-STAGE: February 06, 2009

DOIhttps://doi.org/10.2343/geochemj.13.e1

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