巻号一覧
38 巻 (2004)
- 4 号 p. 203-
- 3 号 p. 117-
- 2 号 p. 45-
- 1 号 p. 1-
38 巻, 2 号
選択された号の論文の7件中1～7を表示しています
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報文
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荻原 成騎2004 年 38 巻 2 号 p. 45-55
発行日: 2004/06/05
公開日: 2017/01/17
ジャーナル フリーThe biomarkers and their specific carbon isotopic compositions (δ13C) have been analyzed in Cretaceous carbonate rocks collected from four areas in Hokkaido, Japan. Anaerobic oxidation of methane (AOM) might occur in Tappu-Kanajirizawa and Teshionakagawa-Abeshinaigawa carbonate rocks, which have found to be related to cold-seep biological fossil communities. The biomarker distributions and their δ13C values showed that these carbonates were presumably linked to Archaea and bacteria associated with AOM in these cold-seep environments. These carbonate samples contained the "tail to tail" linked isoprenoid hydrocarbons, crocetane (2, 6, 11, 15-tetramethylhexadecane), PME (2, 6, 10, 15, 19-pentamethyleicosane), and their unsaturated derivatives. Squalane (2, 6, 10, 15, 19, 23-hexamethyltetracosane), C40 acyclic and cyclic isoprenoid hydrocarbons were also detected. The occurrence of these compounds indicates that Archaea clearly play an important role during carbonate precipitation in the cold-seep environments. Archeal biomarkers were depleted in 13C, indicating that archaeal isoprenoids were biosynthesized from isotopically depleted carbon such as that derived from methane. In addition to the archaeal markers, the isotopically 13C-depleted iso -and anteiso-alkanes, which were most likely derived from sulfate-reducing bacteria, were identified. These results support the model that the sulfate-reducing bacteria might be closely linked to Archaea responsible for the AOM, although these organisms were generally competitive. The Manji-Shikorozawa and Yubari-Utagoezawa carbonates, which were lacking the cold-seep fossil biological communities, showed similar biomarker distribution. Biomarker analyses indicated these carbonates could have potential as cold-seep carbonate, and biomarker is possibly a useful indicator of cold-seep carbonate.抄録全体を表示PDF形式でダウンロード (1151K) -
清棲 保弘, 寺山 晃子2004 年 38 巻 2 号 p. 57-65
発行日: 2004/06/05
公開日: 2017/01/17
ジャーナル フリーMeasurements of CH4 emission and soil temperature on a small bog margin at 1,900 m elevation in the Tateyama Midagahara (36°34'N, 137°33'E) were made on a monthly basis from June to November during 1997-1998. The CH4 fluxes determined by a static chamber technique ranged from 0.31 to 270 mg CH4-Cm-2day-1 and were related to peat temperature. There was a positive relationship between precipitation and CH4 flux: larger precipitation led to larger fluxes. The CO2 flux ranged from 0.026 to 2.8 g CO2-C m-2day-1 and strongly correlated with CH4 flux. Determinations of carbon isotopic compositions in CH4 and CO2 revealed δ13C values of -60.9 to -72.9‰ and -19.2 to -24.9‰, respectively. Comparision of δ13C signatures between CH4 and CO2 suggested that CH4 oxidation is not an important overall control on CH4 emission and indicated that most of the CH4 was formed by mixture of acetate fermentation and CO2 reduction pathways.抄録全体を表示PDF形式でダウンロード (996K)
2003年度日本地球化学会賞受賞記念論文
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兼岡 一郎2004 年 38 巻 2 号 p. 67-84
発行日: 2004/06/05
公開日: 2017/01/17
ジャーナル フリーSince the early study on terrestrial noble gases in 1970s, we have accumulated a lot of knowledges about their distribution and characteristics in the Earth's interior. Noble gas isotopes have unique characteristics such as chemical inertness, incompatible properties, fast mobility of He and so on. By utilizing such characteristics, they work nowadays as an important tool to reveal the state and processes which occur on the Earth. However, there still remain many unsolved problems regarding them. Since noble gases easily degas when magmatic processes occur near the surface, their abundances are quite variable and atmospheric components easily affect noble gases in a magma. Hence, to get primary signatures of a magma, sample selection becomes an important issue to minimize the secondary effect. He and Ne isotopes in the Earth's interior have been revealed to show the solar-type properties. Further, He-Ne isotope sytematics between MORB and OIB sources might imply the difference in He/Ne ratios among OIB and/or MORB sources. In the Earth's interior, 40Ar/36Ar ratios are generally regarded to be high, at least more than 1,000. However, lower values are often observed in mantle xenoliths and volcanic rocks. They are generally explained by the secondary contamination or the effect of recycled materials, but there remain other cases which require additional explanations. Distribution of excess 129Xe should be also examined in more detail. As long as available data are concerned, primordial noble gas isotopes heavier than Ar in the Earth's interior seem to have no difference from the atmospheric values, but He and Ne isotopes are different. Such information requires some additional processes to form the terrestrial noble gas signatures to the components observed in extraterrestrial materials such as solar wind or meteorites. Such problems should be solved to understand the Earth's evolution and its state.抄録全体を表示PDF形式でダウンロード (2068K)
2003年度日本地球化学会奨励賞受賞記念論文
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柴田 智郎2004 年 38 巻 2 号 p. 85-93
発行日: 2004/06/05
公開日: 2017/01/17
ジャーナル フリーNoble gas solubility in liquid is dependent on both interaction energy between solute and solvent and molar volume of noble gas in solvent. The molar volume is more effective on the solubility in silicate melt than the interaction energy. Although ionic porosity (IP) had been considered to control noble gas solubilities, this parameter cannot apply to the solubilities in silicate melts with low IP. We found that noble gas solubilities in silicate melt are correlated with the NBO/Si (non-bridging oxygens per silicon) ratio in wide range of silicate melt composition, independently of nature of network modifying cations. However, solubility data for aluminosilicate melt falls off the correlation line. Although Al3+ is in tetrahedral coordination in aluminosilicate melts with sufficient M+ and M2+ cations for charge-balance, the solubility data can fall on the correlation line if we treat oxygens bonding with MAl4+ or M0.5Al4+ as non-bridging oxygen. This means that the solution of noble gas in silicate melt is mainly dependent on the network of SiO4.抄録全体を表示PDF形式でダウンロード (1035K) -
松本 潔2004 年 38 巻 2 号 p. 95-112
発行日: 2004/06/05
公開日: 2017/01/17
ジャーナル フリーIn the last decade, atmospheric aerosols have attracted considerable attention due to their impact on global climate change. Since 1994, the author has been working on the chemical characterization of marine aerosols over the western North Pacific Ocean, and investigated their physical and chemical properties, spatial and temporal distributions, transport processes, and contributions to cloud condensation nuclei (CCN). From an analysis of long-term observations at Haha-jima Island, the author found that water-soluble organic species are important constituents of CCN in the remote marine atmosphere, and play a key role in cloud formation and indirect radiative forcing processes. Continental outflows cause higher CCN densities and influence the optical properties of clouds over the remote ocean. In addition, the author determined the concentrations of the main chemical components in marine aerosols and their seasonal characteristics over this oceanic region. Higher concentrations of non sea-salt sulfate (nss-SO42-), nitrate (NO3-), ammonium and oxalate were found in the continental air masses, whereas formate and acetate showed seasonal trends associated with marine biospheric activities. In simultaneous observations on four islands around Japan, the author clarified the spatial distribution, source regions, transport mechanism, and transport pathway of land-derived aerosols over the western North Pacific Ocean. For example, mineral particles are an important carrier for acidic species, especially for NO3-, over the seas close to the continent, whereas sea-salt particles act as a significant sink for these species over the remote ocean. Carbonaceous species were affected by biomass burning sources. The atmospheric behaviors of nss-SO42-, NO3-, and carbonaceous species are different from each other, although they are all mainly derived from combustion sources.抄録全体を表示PDF形式でダウンロード (2120K)
博士論文抄録
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笹川 基樹2004 年 38 巻 2 号 p. 113-
発行日: 2004/06/05
公開日: 2017/01/17
ジャーナル フリーPDF形式でダウンロード (194K) -
箕輪 はるか2004 年 38 巻 2 号 p. 114-
発行日: 2004/06/05
公開日: 2017/01/17
ジャーナル フリーPDF形式でダウンロード (192K)
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