巻号一覧
17 巻 (1983)
- 6 号 p. 269-
- 5 号 p. 223-
- 4 号 p. 165-
- 3 号 p. 111-
- 2 号 p. 63-
- 1 号 p. 1-
17 巻, 5 号
選択された号の論文の6件中1～6を表示しています
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Douglas G. Brookins1983 年 17 巻 5 号 p. 223-229
発行日: 1983/10/20
公開日: 2008/04/08
ジャーナル フリーPDF形式でダウンロード (1111K) -
Naohiro Yoshida, Sadao Matsuo1983 年 17 巻 5 号 p. 231-239
発行日: 1983/10/20
公開日: 2008/04/08
ジャーナル フリーAn analytical system to separate N2O in the air was developed to measure the δ15N value and concentration of N2O. The system was designed so that δ15N value and concentration of ca. 1 μmol N2O from ca. 60 l air could be measured with the accuracy of ±0.2‰ and ±10 ppbv, respectively. Air samples were collected at three individual sites in Japan. The average values of δ15N and concentration of N2O for 32 samples with the standard deviation were +8.1 ± 1.0‰ and 316 ± 14 ppbv, respectively. The diversity of the observed data was attributed to the change in the mixing ratio of air masses of different characteristics. A discussion was made on the global cycle of N2O. Bacterial reduction of N2O was proposed to be the major consuming process of N2O on the Earths surface.抄録全体を表示PDF形式でダウンロード (2469K) -
Genki Matsumoto, Kazuo Chikazawa, Haruta Murayama, Tetsuya Torii, Hiro ...1983 年 17 巻 5 号 p. 241-246
発行日: 1983/10/20
公開日: 2008/04/08
ジャーナル フリーMercury contents of 19 soils, 13 lake and pond sediments, 8 epibenthic algae (mostly blue-green algae) and 3 mosses (mostly Sarconeurum glaciale) from the dry valleys of Victoria Land and Ross Island in the Antarctic ranged from 3.0 to 54 μg kg-1 with an average of 14 ± 5.1 at 90% confidence limits, from 2.4 to 71 with an average of 17 ± 10, from 12 to 710 with an average of 190 ± 160 and from 99 to 290 with an average of 170 ± 180 μg kg-1 dry base, respectively. It was indicated that epibenthic algae and mosses accumulate mercury. The correlation coefficient between total organic carbon and mercury contents for all the samples studied was found to be +0.69, indicating that total organic carbon contents are an important factor controlling the distribution of mercury in soils, sediments and organisms in the Antarctic dry valley areas.抄録全体を表示PDF形式でダウンロード (1408K) -
J. R. Richards1983 年 17 巻 5 号 p. 247-255
発行日: 1983/10/20
公開日: 2008/04/08
ジャーナル フリーAfter some discussion of analytical adequacy, Pb-isotope ratios are presented for galenas from the north-west of Western Australia. The data, all double-spike normalised, subdivide into three distinguishable groups in their relationship to the Cumming-Richards Pb-growth Model III. As noted previously, samples with model age 2.7Ga or older exhibit a higher-than-average source Th/U, and a normal dependence of source U/Pb (μ = 238U/204Pb) on country-rock chemical type. Younger samples, on the other hand, exhibit uniformly high μ-values, regardless of host-rock chemistry, and two distinguishable Th/U regimes. For 206Pb/204Pb in the range 14.0–16.5, source Th/U values are close to growth-curve average, whereas for younger samples, 208Pb/204Pb is observed to be very high. The data seem best interpreted in terms of two ‘events’ involving migration of uranium. In the first, at a time near the defined Archaean-Proterozoic boundary, there appears to have been incursion of U into the Pb-source, at a time close to ‘cratonisation’ of the region. The second event, late in the Precambrian, appears to have involved loss of U from the system. Some parallelisms between the isotopic histories of Western Australia and southern Africa are noted.抄録全体を表示PDF形式でダウンロード (2497K) -
Minoru Okumura, Yasushi Kitano, Masatoshi Idogaki1983 年 17 巻 5 号 p. 257-263
発行日: 1983/10/20
公開日: 2008/04/08
ジャーナル フリーThe effect of citrate, malate, lactate and acetate ions in a parent solution on the incorporation of fluoride ions into formed calcite has been studied experimentally. Citrate ions in a parent solution containing no magnesium ions increase intensively the amount of fluoride ions incorporated into magnesium-free calcite, and malate ions do so but moderately, while lactate and acetate ions have little effect on the incorporation of fluoride ions into calcite. The amount of fluoride ions incorporated into low Mg-calcite (smaller than 4% magnesium carbonate) formed from a parent solution containing magnesium ions but no citrate ions remarkably increases with increasing magnesium carbonate content of the formed low Mg-calcite. This trend is in agreement with that observed in marine calcareous skeletons (OHDE and KITANO, 1980). The amount of fluoride ions incorporated into high Mg-calcite formed from a parent solution containing both magnesium and citrate ions is large. The fluoride amount slightly increases with increasing magnesium carbonate content of the formed high Mg-calcite.抄録全体を表示PDF形式でダウンロード (2087K) -
Hideo Tsunakawa, Yoji Kobayashi, Akira Takada1983 年 17 巻 5 号 p. 265-268
発行日: 1983/10/20
公開日: 2008/04/08
ジャーナル フリーEleven samples from six dike swarms in Southwest Japan were dated by the K-Ar method. Most K-Ar ages obtained for these samples indicate that a volcanism as dike intrusions occurred about 15 Ma ago at some areas in the inner zone of Southwest Japan. The previous geochronological studies by other workers have already revealed the occurrence of granitic intrusions and their related effusive rocks at about 14 Ma ago in the outer zone of Southwest Japan. Hence, it is inferred that the igneous activity was intensive in the relatively wide regions of Southwest Japan about 15 Ma ago.抄録全体を表示PDF形式でダウンロード (997K)
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