巻号一覧
35 巻 (2001)
- 4 号 p. 151-
- 3 号 p. 107-
- 2 号 p. 61-
- 1 号 p. 1-
35 巻, 2 号
選択された号の論文の3件中1～3を表示しています
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報文
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高木 真理, 田中 剛, 浅原 良浩, 青木 和弘, 天野 健治2001 年 35 巻 2 号 p. 61-72
発行日: 2001/06/20
公開日: 2017/01/05
ジャーナル フリー87Sr/86Sr ratio as well as dissolved major elements in rainwater, surface water and groundwater around the Kamaishi mine were examined to understand in-situ water-rock interaction. Clay minerals exist in the soil covering the surface. However, they have little effect on the groundwater chemical composition. The groundwater does not change its Na/Ca, Rb/Sr and 87Sr/86Sr ratios in the depths shallower than 300 meters. It is considered that groundwater has been at steady state reaction condition with plagioclase in the surrounding granodiorite. Na/Ca, Rb/Sr and 87Sr/86Sr ratios increase with depth in the deeper aquifers than 300 meters, suggesting that the dissolution of K-feldspar and/or biotite rich in alkaline and high 87Sr/86Sr ratio is prompted. The concentration of Sr is lower in the deeper groundwater probably due to mineral precipitation and/or ion exchange reaction. Rb/Sr ratio of groundwater in the borehole, drilled 10 years ago, on the contrary, decreases with depth and becomes close to the value of bedrock at the deepest. It can be interpreted in two ways. One is a contribution of the deep groundwater and another is the influence of mineral dissolution at an early stage of water-rock interaction. Though the interpretations are seriously different, plagioclase must play an important role at the early stage of chemical weathering process.抄録全体を表示PDF形式でダウンロード (1229K) -
池原 実, 竹本 紀之, 大河内 直彦, 河村 公隆2001 年 35 巻 2 号 p. 73-84
発行日: 2001/06/20
公開日: 2017/01/05
ジャーナル フリーPolycyclic aromatic hydrocarbons (PAHs) were determined in nine deep-sea surface sediments collected from the Australian sector of the Southern Ocean (47°S-66°S). Total concentrations of three- to seven-ring PAHs except for perylene show that they are low in the middle latitudes (〜48°S) but significantly higher toward higher latitudes (65°S). Their concentrations at 65°S are 〜10 times higher than those of the middle latitudes. On the other hand, concentrations of PAHs in the Southern Ocean sediments are remarkably lower than those of the northern North Pacific, indicating an asymmetrical distribution of PAHs between both hemispheres. This may be associated with the concentrated emission sources of PAHs in the middle latitudes in the Northern Hemisphere. Concentrations of retene, which is originated from biomass burning in the middle latitudes, are extremely increased from 60°S to 65°S. These results indicate that PAHs were transported in the atmosphere from source regions to the high-latitude in the Southern Ocean.抄録全体を表示PDF形式でダウンロード (1284K) -
大塚 良仁, 山本 政儀, 小藤 久毅, 横田 喜一郎, 小村 和久2001 年 35 巻 2 号 p. 85-106
発行日: 2001/06/20
公開日: 2017/01/05
ジャーナル フリーThe behavior of 210Pb and 210Po in Lake Biwa, a large mesotorophic lake situated in the Kinki district of Japan, was investigated by analyzing lake water at various depths and precipitation at approximately monthly intervals for a period of 1.5 years, and sediments, streams flowing into and out of the lake. Flux balance calculation indicated that atmospheric deposition was the major source (97% of total) of 210Pb to the lake, and for 210Po growth in-situ from the decay of 210Pb contributed about 75% of the total 210Po supply to the lake. Most (about 90%) of all the 210Pb inputs to this lake was found to be incorporated into sediment. Residence times via sedimentation in the epilimnion and hypoliminion were estimated to be 27 (6-40) and 22 (5-45) days, respectively, for 210Pb and 95 (47-146) and 32 (7-109) days for 210Po. These residence times suggest that there is a difference between 210Pb and 210Po in the extent of their cycling in the water column, with a more rapid removal of 210Pb than 210Po. Overall, 210Pb and 210Po were, furthermore, found to be removed more efficiently during the transit periods of high biological productivity, such as plankton blooms.抄録全体を表示PDF形式でダウンロード (2099K)
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