巻号一覧
14 巻 (1980)
- 6 号 p. 259-
- 5 号 p. 203-
- 4 号 p. 145-
- 3 号 p. 101-
- 2 号 p. 63-
- 1 号 p. 1-
14 巻, 5 号
選択された号の論文の5件中1～5を表示しています
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Hisayuki Teraoka, Jun Kobayashi1980 年 14 巻 5 号 p. 203-226
発行日: 1980年
公開日: 2008/04/08
ジャーナル フリーIn the analysis of natural water, it would be interesting to determine small but significant quantities of trace metals which are concentrated in suspended solids, since some of these metals, derived from geologic formations, mines and industries not only influence the environment for men and animals, but will also help us in tracing metallic resources. Taking advantage of the nation-wide chemical investigations conducted by JUN KOBAYASHI, FUJI MORII and coworkers on various constituents dissolved in the principal Japanese rivers and lakes, the present authors could analyze major and minor metallic elements in the suspended solids by the emission spectrographic method. The following are the results obtained: (1) Markedly higher concentrations of minor elements such as Pb, Zn, Cu, Ni, Mn and Co were found in the suspended solids than in unpolluted soils or in the continental crust reported by TAYLOR (1964). (2) The concentrations of Mn, Cu, Ni, Pb and Sri were found to be markedly high in the Northeastern provinces. This must be due to the higher concentrations of these metals distributed in geologic formations in this section as well as to the influence of many copper and other mines. (3) The distribution of Be happened to divide Japan into two halves. It is markedly lower in the eastern half. Positive correlations were also observed between the concentrations of Be and those of Al and Ti. (4) Owing to the extremely acid nature (pH 2.0) of the Yu River (No. 42) in the Tone river system, caused by the Kusatsu hot sulfuric springs, the concentrations of all metals except Si showed the lowest values, while Si had the highest value. Other inorganic acid rivers which are distributed mostly in the Northeastern provinces, i.e. the Agatsuma River (No. 43, pH 4.3) of the same system and the Ara River (No. 13, pH 3.6), and acid lakes, i.e. Lake Tazawa (No. 32, pH 4.4) and Lake Inawashiro (No. 57, pH 4.5) showed about the same tendency.抄録全体を表示PDF形式でダウンロード (4209K) -
Shizuo Tsunogai, Noriyuki Tanaka1980 年 14 巻 5 号 p. 227-234
発行日: 1980年
公開日: 2008/04/08
ジャーナル フリーThe exchange rate of oxygen across the air-sea interface has been determined from the dissolved oxygen content of sea water in the Funka Bay by applying a closed system model to the Bay water. The change in dissolved oxygen resulting from the biological processes has been evaluated by the change in phosphate. The observations during the period from 1973 to 1980 show a marked seasonal variation in the exchange constants. The mean thickness of the surface film or the molecular diffusion layer at the interface calculated from the exchange constants is 12μm in winter, whereas that is 45μm in summer. Both values are greater than those obtained from laboratory experiments and the field observations of radon profiles, but nearly equal to the value calculated from the mean residence time of carbon dioxide in the atmosphere. The seasonal variation is due to the roughness of the sea surface, suggesting that the exchange constant seems to be proportional to the square or the cube of wind velocity. The Bay is a source of oxygen to the atmosphere, where the net production of oxygen is found to be 1701/m2/yr.抄録全体を表示PDF形式でダウンロード (1769K) -
Ken Shibata, Shinjiro Mizutani1980 年 14 巻 5 号 p. 235-241
発行日: 1980年
公開日: 2008/04/08
ジャーナル フリーWhole-rock samples of siliceous shale, assigned to lower Tithonian by radiolarian fossils, from Hida-Kanayama give a Rb-Sr isochron age of 128±3Ma. K-Ar ages for these samples range from 125 to 133 Ma except two much older ages, which are perhaps caused by the presence of detrital material. On the basis of the concordance between Rb-Sr and K-Ar ages and the lack of significant thermal event, the age of 128Ma is interpreted as indicating the time when the whole-rock became closed with respect to Rb-Sr system, thus there should be a period of about 20Ma between the deposition and chemical diagenesis. The initial 87Sr/86Sr ratio for the shale is determined to be 0.7155 ± 0.0004 and much higher than the contemporaneous marine 87Sr/86Sr ratio. This fact suggests the existence of older rocks in the provenance.抄録全体を表示PDF形式でダウンロード (1580K) -
Masamichi Miyamoto, Hiroshi Takeda1980 年 14 巻 5 号 p. 243-248
発行日: 1980年
公開日: 2008/04/08
ジャーナル フリーThe energy minimization program WMIN of BUSING (1970) has been applied to predict the crystal structures of mantle minerals at high pressure. The repulsive parameters, ionic radius Ai and softness parameter Bi (ionic compressibility) to be used in the predictions are evaluated for Mg2+, Si4+, Al3+, Ca2+, Fe2+ and O2- ions by employing the cell dimensions and atomic coordinates of α-Mg2SiO4(olivine), Fe2SiO4 (fayalite), MgAl2O4(spinel) and CaMgSi2O6(diopside) determined at one atm. These parameters were then used to predict the u-parameter of γ-Mg2SiO4(spinel) by the energy minimization method of WMIN. The u-parameter, 0.3685 was obtained for the observed cell parameter a(=8.0649A). The method and the parameters will be applied to predict other stable minerals in Earth's mantle.抄録全体を表示PDF形式でダウンロード (1493K) -
Ichiro Kaneoka, Harald Mehnert, Shigeo Zashu, Shimpei Kawachi1980 年 14 巻 5 号 p. 249-257
発行日: 1980年
公開日: 2008/04/08
ジャーナル フリーPleistocene volcanic rocks of the Yatsugatake volcanic chain were dated by the K-Ar method in order to study the geochronological significance of the Quaternary volcanic activities along the Fossa Magna, the most remarkable tectonic structure in central Japan. One of the porphyrites of Mt. Nakadake, which are regarded to have formed the root of the Yatsugatake volcanoes shows a K-Ar age of about 1.3 Ma. An andesite of Kasuga volcanic rocks from the northern area of the Yatsugatake volcanic chain indicates a K-Ar age of about 10Ma. K-Ar ages for seven andesites from four different lava units of the southern area range from 0.23 to 0.38Ma. These results are concordant with those estimated stratigraphically. Present results suggest that the volcanic activities to form the present Yatsugatake volcanic chain probably started about 1∼1.5Ma ago. This might have been related to some tectonic effects which triggered volcanic activities around the area like Kirigamine Volcano in central Japan. Furthermore, available radiometric age data together with present results suggest that some volcanic activities already occurred about 1.5∼2Ma ago along the present volcanic front, at least in the Fossa Magna region.抄録全体を表示PDF形式でダウンロード (1849K)
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