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Volume 21 (1987)
- Issue 6 Pages 253-
- Issue 5 Pages 197-
- Issue 4 Pages 139-
- Issue 3 Pages 85-
- Issue 2 Pages 43-
- Issue 1 Pages 1-
Volume 21, Issue 5
Displaying 1-6 of 6 articles from this issue
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W. J. Lin, O. K. Manuel1987 Volume 21 Issue 5 Pages 197-207
Published: 1987
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSThe isotopic composition of xenon has been determined in samples of the Navajo C-1 well gas, Wildcat Field, New Mexico. Our results indicate that xenon in the Navajo well gas contains radiogenic 129Xe and fissiogenic 131-136Xe. The fission yields across heavy xenon isotopes, 131-136Xe, match those reported for the spontaneous fission of 238U; the spontaneous fission of extinct 244Pu accounts for no more than 6% of the excess 136Xe in this well gas. Based on the high value of the ratio of radiogenic 129Xe to CO2 in this gas, we suggest that most this decay product of extinct 129I may have been introduced in a carrier gas of primordial, abiogenic hydrocarbons. It is shown that values of the ratio of radiogenic 129Xe to 244Pu-derived 136Xe in this well gas, in air, and in other terrestrial samples are consistent with a very simple and straight-forward chronology of events in the early solar system that is also compatible with the I-Xe and Pu-Xe record of meteorites.View full abstractDownload PDF (3527K) -
Fumitaka Yanagisawa, Hitoshi Sakai1987 Volume 21 Issue 5 Pages 209-217
Published: 1987
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSSix simulated borosilicate glasses of similar composition but iron and potassium contents were tested for their durability against groundwater leaching at hydrothermal temperature. It was demonstrated that iron has a significant effect on the leaching behavior but pottasium does not within the examined ranges of their contents (Fe2O3 : 2 to 7 wt%, K2O: 0 to 2wt%).View full abstractDownload PDF (2690K) -
Ryoshi Ishiwatari, Yasushi Naito, Kimitaka Kawamura1987 Volume 21 Issue 5 Pages 219-225
Published: 1987
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSDownload PDF (2070K) -
H. Sakai, T. Gamo, K. Endow, J. Ishibashi, T. Ishizuka, F. Yanagisawa, ...1987 Volume 21 Issue 5 Pages 227-236
Published: 1987
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSSince 1984, dense biological communities dominated by giant vesicomyid clam, Calyptogena soyoae, have been located on 1000 to 1200m deep seabed along the foot of the western escarpment of Sagami Bay Japan, by the manned submersible, “Shinkai 2000” and deep-tow TV and photography of Japan Marine Science and Technology Center. Chemical and isotopic study of the clams, sediments and bottom seawater, sampled during the field study of the area using “Shinkai 2000” in 1986, revealed that the clam communities are in close association with methane rich seep systems and that chemoautotrophic sulfur bacteria, living symbiotically in the clam's gill tissues, play an important nutritional role for the seep communities.View full abstractDownload PDF (3260K) -
Determinations of Ga, In and TI in standard rock specimens and chondrites by stable isotope dilutionTsutomu Saito, Hiroshi Shimizu, Akimasa Masuda1987 Volume 21 Issue 5 Pages 237-245
Published: 1987
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSThe concentrations of Ga, In and T1 in 7 standard rocks and in 11 ordinary chondrites have been determined by stable isotope dilution method employing the thermal ionization mass spectrometer. Prior to the mass spectrometry, these elements were preconcentrated by a cation-exchange column. Reproducibility of the present method is estimated to be less than 1%, as long as the sample is well homogenized. It was found that the sample inhomogeneity is the most important restriction in precise and reproducible determination of the elements even in the standard rock powders carefully prepared. Although two analyses of In and T1 on JB-1 (basalt) and DTS-1 (dunite) show good reproducibilities, quite different values are obtained by repeated analyses of In and T1 in AGV-1 (andesite): 56.4 and 114.4ppb on In, and 0.3966 and 0.963 ppm on T1. Our data of chondrites did not agree so well with earlier measurements. The disagreements are considered to be due to inhomogeneity of elements concerned in the sample. All of three impact-melted LL-chondrites show higher abundances of In and T1 with considerable scattered values, which suggests inhomogeneous distribution of these elements in the meteorites. The isotopic composition of Ga, In and T1 in reagents have been also measured precisely by a thermal ionization mass spectrometer.View full abstractDownload PDF (2706K) -
Masahiro Yamamoto, Tsugio Shibata, Minoru Kusakabe1987 Volume 21 Issue 5 Pages 247-251
Published: 1987
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSSulfur and oxygen isotope ratios were determined for eight anhydrite samples (seven from silicate rocks and one from a marble) from the Iratsu peridotite-hornblendite-epidote amphibolite complex, central Shikoku, Japan. The δ34S values of anhydrite are in the range from +4.7 to +11.0‰. The δ18O values of anhydrite from the silicate rocks are in the range from +8.6 to +10.2‰ and that from the marble is +12.4‰. The fairly uniform δ18O values may indicate that these anhydrites were re-equilibrated with respect to oxygen isotopes with host rocks during the Sambagawa metamorphism. The rather variable, high δ34S values of anhydrite suggest that it is not cognate with the original rocks from which the host rocks were derived. The obtained δ34S values do not provide a straightforward solution concerning the source of sulfur for these anhydrites.View full abstractDownload PDF (1633K)
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