巻号一覧
67 巻, 9 号
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中川 善兵衛, 小坂 丈予, 浦部 和順, 山田 久夫1972 年 67 巻 9 号 p. 283-290
発行日: 1972/09/05
公開日: 2008/08/07
ジャーナル フリーThe weathering process of quartz-diorite mass in Senmaya district, Iwate Prefecture, was studied from chemical and mineralogical angles. Especially the relationship between the compositional changes of the weathered rocks and their main constituent minerals was detailedly discussed.
The non-altered quartz-diorite is chiefly composed of quartz, plagioclase, hornblende and biotite, together with few apatite and magnetite. As weathering proceeds, most of the primary minerals, plaigoclase, hornblende and biotite, are gradually eliminated and secondary minerals such as vermiculite, kaolin etc. appear in stead. The change in chemical composition of the weathered rocks is almost controlled by the solubility of each chemical component under netural conditions.
Among the primary minerals, biotite is most sensitive for weathering, the sequence of the alteration being as follows:
biotite-hydrobiotite-vermiculite-kaolin mineral
In the earlier stage of the weathering, the alteration process of biotite was mostly affected by its original crystallographic structure, so that the change in chemical composition of that mineral differs markedly from that of the host rock. But it is also controlled by the solubility of each chemical component, thus the compositional change becomes to be similar to that of the host rock in the later stage.抄録全体を表示PDF形式でダウンロード (1463K) -
谷口 宏充1972 年 67 巻 9 号 p. 291-300
発行日: 1972/09/05
公開日: 2008/08/07
ジャーナル フリーThe nature of volcanic glassed in andesitic to rhyolitic rocks have been studied by means of infrared absorption and other several methods. The main results are as follows:
(1) The atomic distance of Si-O bond in volcanic glasses becomes random with the increase of contents of intermediate and modifying ions.
(2) The network structure of volcanic glasses expands with the increase of contents of intermediate and modifying ions.
(3) The network structure of volcanic glasses expands with the increase of contents of intermediate and modifying ions.
(4) In the structure of volcanic glasses, most of Al3+ ions substitute for Si4+ ions, and are tetrahedrally coordinated.
(5) In the structure of pumiceous glass and obsidian glass, H2O(+) presents mainly as monomeric hydroxyl and minorly as hydrogen-bonded hydroxyl. On the contrary, in perlitic glass, H2O(+) presents as hydrogen-bonded water and monomeric hydroxyl.抄録全体を表示PDF形式でダウンロード (710K) -
阿部 宏, 青木 守弘1972 年 67 巻 9 号 p. 301-310
発行日: 1972/09/05
公開日: 2008/08/07
ジャーナル フリーSynthetic anorthite was subjected to alter in aluminum sulfate solution at low temperature and pressure. Gypsum, anhydrite, kaolinite and boehmite were obtained as the alteration products. When the alteration products were treated again in magnesium chloride solution, montmorillonite was formed under certain limited conditions. The chemical reaction involved is described as follows; 3(CaSO4•2H2O)+24H4SiO4+10Al(OH)3+2MgCl2=3[Ca0.83Si8(Al3.34)Mg0.66O20(OH)4]+2CaSO4+60H2O+4HCl+H2SO4
The relation between Ca-sulfate mineralization and simultaneous alteration observed in Kuroko-type deposits was discussed on the basis of the present experiments.抄録全体を表示PDF形式でダウンロード (625K) -
大貫 仁, 田切 美智雄1972 年 67 巻 9 号 p. 311-322
発行日: 1972/09/05
公開日: 2008/08/07
ジャーナル フリーSix hornblendes and their host amphibolites collected from an outcrop in the Hitachi district were studied chemically. The metamorphic grade of the host rocks corresponds to the higher temperature part of the epidote amphibolite facies. There is no regular relation between the alkali contents in the hornblendes and their host rocks. With increasing Ca/(Ca+Na) ratio of the host rock, this ratio of the hornblende remains nearly constant, although anorthite molecule in the coexisting plagioclase increases. Thus, the variation of Ca/(Ca+Na) ratio of the host rock is mainly reflected on the composition of the plagioclase, but not on that of hornblende.抄録全体を表示PDF形式でダウンロード (750K)
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