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Volume 27 (1993)
- Issue 2 Pages 65-
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Volume 27, Issue 2
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Original Papers
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Osamu NAGAFUCHI, Shiroh TAGAMI, Tetsuya ISHIBASHI, Koichi MURAKAMI, Ry ...1993 Volume 27 Issue 2 Pages 65-72
Published: November 05, 1993
Released on J-STAGE: December 12, 2016
JOURNAL FREE ACCESSRime and snow samples were collected at mountain sites in Kyushu for 2 years, from 1990 to 1992. The soluble substance in rime and snow were measured to evaluate the atmospheric environments of the mountain region. It was found that the ion concentrations in rime melt samples were considerably higher than those of snow and that pH of the rime melts was lower than that of snow. No influence from carrier plants upon soluble components in rime was found. In the light of the relative composition of both anion and cation in rime, it seems that the origins of acid components in rime differ from those of snow. From these results, it is suggested that rime reflects local atmosphere situation at the sampling sites better than snow. Therefore, for evaluation of atmospheric environments, it is conceivable that rime will be a useful indicator.View full abstractDownload PDF (958K) -
Yoshihiro HIRAOKA1993 Volume 27 Issue 2 Pages 73-82
Published: November 05, 1993
Released on J-STAGE: December 12, 2016
JOURNAL FREE ACCESSSoils formed on underlying granitic rocks have similar chemical characteristcs of their rocks. In this paper, soil samples (n=196) and rock samples (n=82) were collected around Mt. Hiei and Mt. Hira, and analyzed quantitatively about silicon, calcium, potassium, iron, aluminum, titanium, strontium and rubidium by X-ray Fluorescence Spectrometry. Chemical data were classified into three groups mainly, the Hiei type, the Hira type and the Kurama type by multivariate statistical analysis. Soils of the Hira type are rich in rubidium and potassium, whereas the Kurama type rich in strontium and calcium and the Hiei type was intermediate between the Hira and the Kurama types. Thus, it was revealed that the inorganic chemical features in granitic soils and rocks were different from each district, and it is suggested that it is possible to discriminate the unlocated granitic soils or rocks through anlyzing their diagnostic elements.View full abstractDownload PDF (765K) -
Mitsuru EBIHARA1993 Volume 27 Issue 2 Pages 83-95
Published: November 05, 1993
Released on J-STAGE: December 12, 2016
JOURNAL FREE ACCESSAlthough more than 20 years have passed since the discovery of the debris of 244Pu in meteorites, its application to chronology is not yet fully established. In this paper, several problems involved in 244Pu chronology are discussed in conjunction with those for 129I chronology and the possibility of 244Pu chronology is sought. The most serious problem for 244Pu chronology is the lack of a reference nuclide for 244Pu. Although an ideal nuclide for a reference of 244Pu is not available, however, individual candidates for a reference element are proposed for several specific samples, e.g., uranium or rare earth elements (REE's) for bulk chondrite samples and light REE's for the acid-residual fraction of the most primitive ordinary chondrites. Using the literature values of 244Pu/238U and the nucleosynthesis model by Fowler (1987), formation intervals are calculated for several meteorite specimens. There appears to be an apparent discrepancy in calculated ages between 244Pu and 129I chronologies; formation intervals based on 244Pu are about double those from 129I chronology, suggesting that a considerable fraction of 129I was later added to the solar nebula after the end of nucleosynthesis responsible for 244Pu and almost all other nuclides.View full abstractDownload PDF (1392K) -
Yasuhiro KIYOSU, Hideharu MIYAJIMA, Noriko ASADA1993 Volume 27 Issue 2 Pages 97-108
Published: November 05, 1993
Released on J-STAGE: December 12, 2016
JOURNAL FREE ACCESSThermal spring waters from the Myoko volcano comprise near-neutral pH chloride, bicarbonate and sulfate types. Chemical and isotopic evidence suggests that the Na-Cl and Ca-HCO3 waters are derived from a hydrothermal aquifer formed by mixing of magmatic gases with deep circulating groundwater. The SO4 water is produced by reaction of surface waters and gaseous phase, which consist for the most part of the CO2 and H2S after boiling of the thermal aquifer. The isotopic composition of waters from thermal springs shows mainly their meteoric origin. Hydrochemical and gas geothermometers indicate that high enthalpy chloride type gluids (≦300℃) are present at deep levels beneath the Myoko volcano. The N2, Ar and He contents in the lowtemperature fumarolic gases (〜100℃), which are essentially fed by steam boiled off from the hydrothermal aquifer, suggest a relatively high contribution of magmatic fluids. On the basis of isotope evidence, it is likely that the thermal fluid in the aquifer contains thermogenic gases derived by thermal decomposition of organic matter in sedimentary basement rocks.View full abstractDownload PDF (964K) -
Moritsugu KITAMURA, Minoru SUGIYAMA, Tetsuji OHHASHI, Nobuyuki NAKAI1993 Volume 27 Issue 2 Pages 109-118
Published: November 05, 1993
Released on J-STAGE: December 12, 2016
JOURNAL FREE ACCESSWe surveyed the sulfur isotope ratio of sulfate in rain waters collected in Kanazawa city from December 1986 to November 1991 to investigate the origin of sulfate in rain waters. The sulfur isotope ratio of sulfate in rain waters varied from +0.9 to +14.7‰ and its average was +6.3‰. The ratio was higher in winter than that in the other seasons. The sulfur isotope ratio of nss-sulfate which was calculated by elimination of the contribution of sea salts from the sulfur isotope ratio of rain water sulfate also showed relatively higher value in winter. This seasonal variation suggested that sulfate in the rain waters collected in winter was mainly derived from the source having a higher sulfur isotope ratio, such as coal combustion in northern China, (north of Yangtze-jiang).View full abstractDownload PDF (946K) -
Koichi MIMURA1993 Volume 27 Issue 2 Pages 119-134
Published: November 05, 1993
Released on J-STAGE: December 12, 2016
JOURNAL FREE ACCESSIn order to examine the presence of abiogenic hydrocarbons in igneous rocks, various rock types on the earth were collected and analyzed. The result shows that tectonites in ophiolites and mantle xenoliths in alkali basalts usually contain heavy hydrocarbons. The chromatogram pattern of the heavy hydrocarbons essentially resembles that of crude oils. The heavy hydrocarbons could be contaminated after the rocks raised to the earth surface. Nevertheless, several lines of evidence such as the geological occurrence, the origin of rocks and the carbon isotope data rule out the possibility of the contamination; the detected hydrocarbons must be inherent in iguneous rocks. Three possibilities may be assigned to the origins of the heavy hydrocarbons disclosed by this study. The first is that they have been inorganically synthesized in the mantle. The second is that they are recycled materials biologically produced on the earth. The third is that they are remnants of primordial materials delivered by meteorites and comets in the earth. It is nearly impossible to decide at the present time which of these three hypotheses is the closest to the real origin. The heavy hydrocarbons, however, must provide us important information on the carbon geodynamic cycle.View full abstractDownload PDF (1444K) -
Naotatsu SHIKAZONO1993 Volume 27 Issue 2 Pages 135-139
Published: November 05, 1993
Released on J-STAGE: December 12, 2016
JOURNAL FREE ACCESSAnnual hydrothermal flux of arsenic from back arc basins and mid-ocean ridges was estimated based on arsenic concentration of hydrothermal solutions and seawater circulation rate. Estimated values are (0.2-5.2)x1011 g/yr at island arc-back arc basins and (0.8-1.6)x109 g/yr at mid-ocean ridges. The estimated total hydrothermal input flux ((0.28-5.36)×1011 g/yr) is similar to or higher than that of river flux (0.78×1011 g/yr). Total input flux ((1.6-6.1)×1011 g/yr) is same in orders of magnitude to pyrite output flux ((1.3-2.9)×1011 g/yr). Subduction flux is estimated to be (4.0-8.2)×1010 g/yr. The comparison of subduction flux with hydrothermal flux from island arc-back arc basins suggests that the subduction flux from crust to mantle is small, compared with arsenic circulation in crust-ocean-atmosphere system.View full abstractDownload PDF (494K)
Achievement for Geochemical Society Award
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Jun-ichi MATSUDA1993 Volume 27 Issue 2 Pages 141-160
Published: November 05, 1993
Released on J-STAGE: December 12, 2016
JOURNAL FREE ACCESSWe synthesized vapor-growth diamonds and shock-produced diamonds, and examined elemental abundances and isotopic compositions of noble gases in them. The trapping mechanism of noble gases in these synthetic diamonds has been verified from this study. We have examined various features of diamonds in ureilites and compared with those in synthetic diamonds, and concluded that the vapor-growth hypothesis is better than the impact-shock hypothesis for the origin of diamonds in ureilites. The diamond (and graphite, amorphous carbon, too) have been deposited on early condensate such as Re, Ir, W etc. in the primitive solar nebula, which explains the chemical features of vein material in ureilites. The vapor-growth model shows that nebular processes are primarily responsible for the chemical composition of ureilites.View full abstractDownload PDF (2064K)
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