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Volume 19 (1985 - 198･･･
- Issue 6 Pages 289-
- Issue 5 Pages 251-
- Issue 4 Pages 181-
- Issue 3 Pages 113-
- Issue 2 Pages 59-
- Issue 1 Pages 1-
Volume 19, Issue 3
Displaying 1-7 of 7 articles from this issue
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Kimitaka Kawamura, Ryoshi Ishiwatari1985 Volume 19 Issue 3 Pages 113-126
Published: June 20, 1985
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSA lacustrine sediment has been subjected to laboratory heating at 68–325°C for 24h. Various lipid classes were extracted from the unheated and heated sediment samples and analyzed by gas chromatography and GC-MS. The compounds recognized include; saturated and unsaturated fatty acids, β-, ω- and (ω-1)-hydroxy acids, α, ω-dicarboxylic acids, fatty alcohols and n-alkanes. The carbon and nitrogen contents and the KMnO4 oxidative degradation products (α, ω-diacids) of geopolymers (kerogen and humic compounds) in the extracted residues were determined. The absorbance at 400nm of humic compounds extracted from the residue was also measured. Most of the extractable (unbound + bound) lipid class compound concentrations increase with temperature from 150 to 250°C. This can be interpreted in terms of: (1) a release of compounds incorporated and/or associated with geopolymers in a tightly bound form, and/or (2) their production by α-, β-, ω- and (ω-1) oxidation of certain precursors or by other mechanisms. Some organic compounds decompose after reaching maximum concentrations at different temperatures: β-hydroxy acids (154°C), ω-hydroxy acids (179°C), (ω-1)-hydroxy acids (179°C), n-alcohols (229°C), phytanic acid (254°C), α, ω-dicarboxylic acids (279°C). However, alkanoic acids do not decrease even at 325°C. Normal alkanes increase throughout the heating. Their concentrations at 325°C are 16 times higher than in the unheated sediment. The amounts of KMnO4 degradation products (diacids) of geopolymers drastically decrease at temperatures higher than 200°C, which implies that structural changes of kerogen and humic compounds occur upon heating. Absorbance of humic compounds also shows a drastic change at the same temperatures.View full abstractDownload PDF (4327K) -
M. Ozima, S. Zashu, D. P. Mattey, C. T. Pillinger1985 Volume 19 Issue 3 Pages 127-134
Published: June 20, 1985
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSHelium and argon isotopic data of diamonds suggest that the mantle where diamonds crystallised has remained almost a closed system for most of the Earth's history. The 3He/4He–3He evolution diagram implies that at least two diamonds studied are nearly as old as the Earth. Carbon isotopic compositions of the stones studied varied from -3.3 to -29.7‰, while older diamonds show less deviation from the generally considered average δ13C for diamonds.View full abstractDownload PDF (1932K) -
Yuji Sano, Akiko Urabe, Hiroshi Wakita, Hitoshi Chiba, Hitoshi Sakai1985 Volume 19 Issue 3 Pages 135-148
Published: June 20, 1985
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSWe have measured chemical compositions (CO2, CH4, N2, O2, H2S, H2, He, Ne and Ar), and isotopic compositions of light elements (δ13C, δ15N and δD) and of rare gases (He, Ne, Ar, Kr, and Xe) in seven gaseous and four fluid samples collected in Icelandic geothermal areas. Major chemical constituents of the gas samples are CO2, N2, H2 and H2S. Isotopic Compositions of Ne, Kr and Xe are indistinguishable from those of the atmosphere within the experimental accuracy of this study. There are slightly lower 40Ar/ 36Ar ratios than in the air for samples with extremely high 3He/4He ratios. No positive evidence for excess 129Xe is found. The measured 3He/4He ratios in the samples can be explained in terms of mixing among three end members: MORB-type He with a 3He/4He ratio of 1.1 × 10-5, plume-type He of 5.0 × 10-5, and atmospheric He of 1.4 × 10-6. Samples obtained from the northeastern part of the island contain typical MORB-type He, whereas, significant contributions (up to 33%) of plume-type He are apparent in samples from the southern region. Based on the 13C/12C ratios, CO2 in Icelandic gases is considered to be directly derived from magma, whereas CH4 may be formed by reaction of reduced carbon with water in the source magma. There is an inverse correlation between the 3He/4He ratios and δ15N values in Icelandic gases, suggesting co-genetic origin of He and N2.View full abstractDownload PDF (4275K) -
Harue Masuda, Hitoshi Sakai, Hitoshi Chiba, Michiji Tsurumaki1985 Volume 19 Issue 3 Pages 149-162
Published: June 20, 1985
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSNa-Ca-Cl-(HCO3) type waters of Cl content ranging from a few hundred mg/l to more than twice that of seawater widely distribute in the studied area. From the chemical and isotopic compositions and reservoir rock types, these waters are classified into the Arima brines (Type I, Arima-type brine of Matsubaya et al., 1973), dilute carbonated waters from Paleozoic sedimentary rocks (Type II), and those from Cretaceous to Paleogene acidic igenous rocks (Type III). Arima brines are highly saline (Cl = 1, 000 ∼ 36, 000mg/l) and are considered to be mixtures of a unique deep brine of δD = -32‰, δ18O = +10‰ and Cl = 54g/l and bicarbonate-rich dilute waters of meteoric origin. From the chemical and isotopic data presented in this paper and in the light of the high 3He/4He ratios observed in gases of Arima brines (Sano and Wakita, 1985; Nagao et al., 1981), it is likely that the deep brine originates from deep-lying magma underneath the Arima Spa or from sedimentary rocks during metamorphism induced by the magma. Most waters of Types II and III are often carbonated waters of meteoric origin. Chemical compositions of these waters suggest that both of them are formed by interaction between CO2-bearing meteoric water and wall rocks. Among the waters of these groups studied, only the Tojo water (Cl = 6, 380mg/l) exhibited clear evidence of contribution from Arima brines. Other waters have no such sign or are too dilute to find any relation with Arima brines.View full abstractDownload PDF (3890K) -
Hidehiko Shimazaki, Hitoshi Sakai, Hiroaki Kaneda, Min Sung Lee1985 Volume 19 Issue 3 Pages 163-169
Published: June 20, 1985
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSIsotopic composition is determined for ore sulfur from seventeen Au-Ag, six W-Mo and one fluorite deposits in the southern Korean Peninsula. The age of ore formation ranges from pre-Cambrian to Cretaceous. Together with the data available in the literature, the following characteristics are recognized: 1) most δ34S values fall in the narrow range of +2 to +7‰, 2) no systematic variations are observed among the deposits of different geologic environments and with different workable metals, and 3) exceptional negative δ34S values are observed in some deposits located in and near the Taebaegsan area. Predominance of ore sulfur with positive δ34S values suggests the biogenic sulfur-poor nature of constituent sedimentary rocks in the Korean continental crust.View full abstractDownload PDF (1978K) -
Toshitaka Gamo, Yoshio Horibe1985 Volume 19 Issue 3 Pages 171-174
Published: June 20, 1985
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSA gas chromatographic method for separating CO2 and N2O was developed to measure 13C/12C ratios of atmospheric CO2. The mixture of N2O and CO2, which was condensed out from an air sample, was separated by passing through a column packed with porous silica beads, and only CO2 was recovered for δ13C measurements. It was confirmed that the gas chromatographic separation of CO2 does not change the δ13C value of CO2. Urban air samples in Tokyo and oceanic air samples in the northwestern Pacific were analyzed by using this method. The δ13C value of separated CO2 was shown to be 0.20 ± 0.03‰ greater than the value obtained when the CO2-N2O mixture was directly introduced to the mass spectrometer.View full abstractDownload PDF (1227K) -
Akira Shimoyama, Osamu Matsubaya1985 Volume 19 Issue 3 Pages 175-179
Published: June 20, 1985
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSStable carbon isotope study was carried out on coexisting bitumen and kerogen in sediments of the Shinjo basin. The δ13C values of bitumen and kerogen change from −26 to −22‰ and from −25 to −21‰, respectively, from the top to the bottom sediments of an about 1, 600m thick profile. The difference in δ13C between bitumen and kerogen at each horizon is approximately constant (average, −0.89‰), even down to the horizones where oil generated. This result shows that bitumen was liberated from kerogen, but no specific isotopic fractionation was involved in the oil-generating zone in comparison to non oil-generating zone. It also shows that oil components at each horizon have been little contaminated by those from adjacent horizones above and below.View full abstractDownload PDF (1517K)
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