GEOCHEMICAL JOURNAL
Online ISSN : 1880-5973
Print ISSN : 0016-7002
ISSN-L : 0016-7002
15 巻 , 6 号
選択された号の論文の5件中1~5を表示しています
  • Kazuhiro Suzuki
    1981 年 15 巻 6 号 p. 295-303
    発行日: 1981/12/20
    公開日: 2008/04/08
    ジャーナル フリー
    The distribution of REE (La and Ce) in a hornblende cumulate was investigated with an electron probe microanalyser. The cumulate consists of cumulus kaersutite, augite, titanomagnetite and apatite and such intercumulus minerals as green hornblende, titanomagnetite, plagioclase, apatite and sphene. La and Ce are concentrated in grain boundaries between minerals as well as in apatite and sphene. Grains of cumulus apatite are homogeneous in REE contents, except for rims in contact with augite where REE contents conspicuously increase towards augite. Intercumulus apatite and sphene exhibit decreasing REE distributions from the core to the rim, which are followed by increases when the rims have contact with augite, kaersutite and green hornblende. The constant and the outward decreasing REE distributions may be best explained in terms of surface equilibrium crystallization from infinite main liquid and finite pore liquid, respectively. The formation of REE-rich rims of apatite and sphene and the grain boundary concentration of REE are hardly explained by the model, but may be attributed to a subsolidus diffusion process.
  • Boniface C. E. Egboka
    1981 年 15 巻 6 号 p. 305-314
    発行日: 1981/12/20
    公開日: 2008/04/08
    ジャーナル フリー
    Detailed distribution patterns of bomb tritium (3H), chloride (Cl-), sulphate (SO2-4), oxygen-18 (18O), and deuterium (2H) are described for two unconfined shallow sand aquifers at Canadian Forces Base (CFB), Borden, Ontario, and Whiteshell Nuclear Research Establishment (WNRE), Pinawa, Manitoba, both in Canada. The study areas were highly instrumented with groundwater monitoring and sampling devices consisting of multilevel samplers and bundle piezometers. Groundwater samples were collected regularly and seasonally, and analysed for the isotopes (3H, 18O and 2H) and the dissolved geochemical constituents (Cl- and SO2-4). The samples were collected at several depths within the aquifers and along various directions. The geochemical parameters were interpreted in relation to the groundwater movement. Bomb 3H showed two concentration patterns indicating two groundwater age-zones. An upper tritiated zone reflects young water recharged since the beginning of nuclear tests in 1953. The lower untritiated old water indicated water recharged before 1953. Thus, the recharge and discharge 0 areas were established, and groundwater velocity and hydraulic conductivity were calculated for the description of the groundwater flow. The chloride and sulphate patterns were used to delineate the areal extent of the leachate plume in the aquifer beneath an abandoned landfill at CFB Borden. The sulphate concentrations at WNRE aquifer indicated two possible sources of groundwater recharge. The 18O data for the Borden aquifer suggested that isotopic fractionation was occurring in the landfill so that 18O enrichment was observed within the leachate plume. The 18O and 2H data from WNRE aquifer showed that an evaporative effect on the recharged groundwater was evident, resulting in slight enrichment in 18O and 2H as reflected by the seasonal fluctuations on recharge.
  • Naoki Onuma, Masataka Hirano, Naoki Isshiki
    1981 年 15 巻 6 号 p. 315-324
    発行日: 1981/12/20
    公開日: 2008/04/08
    ジャーナル フリー
    Ca, Sr and Ba contents of various volcanic rocks from four volcanoes (Okata, Gyojanoiwaya, Fudeshima and Oshima) in Oshima, Izu Islands, Japan, have been determined by an inductively coupled plasmaoptical emission spectrometry. In a Sr/Ca-Ba/Ca diagram, three older volcanoes (Okata, Gyojanoiwaya and Fudeshima) gave the same Sr/Ca-Ba/Ca systematics, while younger volcano (Oshima) showed a different Sr/Ca-Ba/Ca systematics. The two different systematics seem to have branched off from a common precursor, suggesting that the primary magma was the same in terms of degree of partial melting of “mantle materials”, but crystal fractionation process in “magma chamber” was different.
  • Akio Inazumi, Toshiyuki Isobe, Toshikazu Tarutani
    1981 年 15 巻 6 号 p. 325-332
    発行日: 1981/12/20
    公開日: 2008/04/08
    ジャーナル フリー
    Five types of ESR signals were observed in shales. The resonance composed of six lines near geff = 2 (type A) is attributed to Mn(II). Type A resonance is divided into two groups on the basis of its line shape; one exhibits six sharp lines (type A-1), and another shows relatively broad lines (type A-2). The geff = 2 broad resonance (type B) may be attributed to Fe(III). The geff sharp resonance line (type C) probably results from stable organic free radicals. The geff = 4.1 resonance (type D) can be attributed to high spin Fe(III) occupying sites of orthorhombic symmetry in clay minerals. Some of the shales show an inclined signal covering a wide magnetic field (type E). Combination of ESR measurements and leaching experiments made it possible to survey the distribution and states of some elements in shales. In shales which exhibit type A-1 resonance overlapped with type A-2 resonance, Mn(II) is randomly distributed both in calcite and clay minerals. In shales which exhibit only type A-2 resonance, Mn(II) is associated mainly with clay minerals. Most of the iron in shales is bound to clay minerals. A part of the iron in clay minerals is present as Fe(III) which shows type D resonance.
  • Hideo Tsunakawa
    1981 年 15 巻 6 号 p. 333-335
    発行日: 1981/12/20
    公開日: 2008/04/08
    ジャーナル フリー
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