巻号一覧
71 巻, 5 号
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逸見 吉之助, 妹尾 護, 黒原 広道, 山下 祐一1976 年 71 巻 5 号 p. 125-136
発行日: 1976/05/05
公開日: 2008/08/07
ジャーナル フリーMajor and some of minor components (Ni, Co, Sr and Ba) of twenty-two specimens of andesitic rocks from Goshikidai, Kagawa Prefecture were analyzed.
Most of the rocks occur as nearly horizontal plateau lavas with the following sequencies.
Characteristics of the Goshikidai rocks are their low iron contents and coexistences of two types of rocks with medium and high potash contents. The K2O contents (about 1.6%) of L3 and U1 are near to those of common calc-alkaline andesite, whereas K2O (about 2.6%) of the others fall within the range of high-potash andesite.
The mineral compositions and the textures of rocks depend not only on their nonvolatile components but also on their volatile components (water and oxgen). Fe2O3/FeO ratios of sanukite are extremely low.
Relations of Ni contents with Al2O3, Co and FeO*/MgO were discussed.抄録全体を表示PDF形式でダウンロード (410K) -
阿部 智彦, 青木 謙一郎, 舟山 裕士1976 年 71 巻 5 号 p. 137-146
発行日: 1976/05/05
公開日: 2008/08/07
ジャーナル フリーIn Sendai area, enormous volume of volcanic rocks erupted as pyroclastic flows or lava flows during the early Miocene to late Miocene in time. These volcanic rocks consist mainly of calc-alkaline andesite and dacite, with subordinate amounts of tholeiitic basalts and andesites.
New analyses are presented for 20 representative calc-alkaline andesite-dacite and 12 tholeiitic basalt-andesite. All of the volcanic rocks are characterized by high CaO and very low Na2O and K2O, and Galc-alkaline series are very similar to those of the tholeiite province of the Quaternary volcanoes in northeastern Japan.抄録全体を表示PDF形式でダウンロード (440K) -
中牟田 義博1976 年 71 巻 5 号 p. 147-156
発行日: 1976/05/05
公開日: 2008/08/07
ジャーナル フリーZeolites occur abundantly in the Tertiary sedimentary rocks distributed near Tsuyazaki, Fukuoka Prefecture. These zeolites and clay minerals associated with them were investigated mainly by x-ray diffraction.
The zeolites occurring in amygdales, veinlets and filling materials of conglomerate were identified as heulandite, stilbite and laumontite, and those replacing matrix and plagioclase grain in sandstone were heulandite and laumontite. Of the latter group, heulandite occurs throughout the whole stratigraphical horizon, but laumontite is recognized only in the lower horizon. This fact suggests that the sedimentary rocks have been suffered the alteration of heulandite-analcime subfacies of Seki (1968), and the degree of alteration is a little higher in the lower horizon.
Most of the clay minerals associated with zeolites are interstratified minerals of illite and montmorillonite and chlorite minerals. Kaolin mineral and celadonite are rarely found. The amounts of montmorillonite layers in the interstratified minerals of illite and montmorillonite are estimated by visual inspection to range from 40 to 90%. The chlorite minerals in the rocks in the upper horizon consist of Ib(β=90°) FeMg-chlorite and interstratified mineral of chlorite and saponite in contrast with those in the lower horizon being FeMg-chlorite only. The interstratified mineral of chlorite and saponite contains 30-50% saponite layers.抄録全体を表示PDF形式でダウンロード (475K)
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