巻号一覧
35 巻 (1995 - 1996)
- 4 号 p. 165-
- 3 号 p. 93-
- 2 号 p. 47-
- 1 号 p. 1-
35 巻, 1 号
選択された号の論文の3件中1～3を表示しています
- |<
- <
- 1
- >
- >|
-
石英とNH4含有セリサイトの鉱物学的性質中川 昌治, 中本 順子, 吉原 俊昭1995 年 35 巻 1 号 p. 1-14
発行日: 1995/07/28
公開日: 2011/09/20
ジャーナル フリーMineral parageneses and mineralogical properties of quartz and NH4-bearing sericite at the Izumiyama pottery stone deposit, Saga Prefecture, have been examined. The deposit was formed by hydrothermal alteration of a rhyolite intrusion. The deposit can be divided into four zones: 1) the sericite zone with sericite vein, 2) the sericite-kaolinite zone, 3) the weakly altered zone (I) and 4) the weakly altered zone (II), from the center to the outer of the alteration area. The typical Izumiyama ore of the sericite zone is composed mainly of quartz and sericite. The sericite-kaolinite zone consists of quartz, sericite and kaolinite. The weakly alterd zone (I) contains residual orthoclase. The weakly altered zone (II) contains residual sanidine and small amounts of mica/smectite with 20-50% smectite layers. Buddingtonite is also contained in some ores of the weakly altered zones.
X-ray diffraction peaks of the quartz are broad. The cell dimensions are considerably large with a=4.9147-4.9153Å and c=5.4054-5.4058Å at 18°C. The high-low inversion peak in the DTA curve is broad and the peak temperature is 10-14°C lower than that of standard quartz. The quartz sample in the center of the hydrothermal alteration has smaller cell dimensions and higher inversion temperature than the sample in the outer alteration zone.
Sericite in the inner two zones is mica with a little amount of smectite layer (0-5%). On the other hand, sericite in the weakly altered zone (I) is irregularly interstratified mica/smectite with 5-15% smectite layers, and the crystallite size is thinner than that in the inner zones. Basal spacing of sericite ranges from 10.063 to 10.174Å due to the extent of NH4 incorporation in the interlayer site. Sericites having high content of interlayer NH4 occur in the weakly altered zone (I), where buddingtonite is the main coexisting mineral. The distribution patterns of these NH4-bearing minerals suggest that the enrichment of NH4 in the Izumiyama pottery stone is a result of the interaction between the hydrothermal solution and sedimentary xenoliths in original rhyolite.抄録全体を表示PDF形式でダウンロード (5945K) -
南條 正巳, 小林 慶一郎, 庄子 貞雄1995 年 35 巻 1 号 p. 15-23
発行日: 1995/07/28
公開日: 2011/09/20
ジャーナル フリーThere are known contradictory reports with regard to the reactivity of phosphate with exchangeable Al. When 10 mgP/l of KH2PO4 was added to soils, no significant correlation was obtained between the exchangeable Al contents and the decrease in phosphate sorption due to removal of exchangeable Al. On the other hand, almost one to one relationship was obtained between exchangeable Al contents and the decrease in phosphate sorption due to removal of exchangeable Al when 0.189 M of ammonium phosphate of pH7.0 was used. The objective of this study is therefore to elucidate the reactivity of Na2HPO4 and NaH2PO4 with exchangeable Al in soils.
Using 2 soils with different clay mineral composition and an Al3+-saturated smectite, the following conclusions were obtained.(1) Na2HPO4 selectively reacted with the exchangeable Al under the coexistence of active Al and Fe such as Al-humus and hydrous Fe oxides.(2) Low concentration of NaH2PO4 (i.e. 5mM or less) hardly reacted with exchangeable Al and mostly sorbed by active Al and Fe.(3) A decrease in the exchangeable Al of Al3+-saturated smectite was much smaller than those for 2 soils, appearing that the exchangeable Al scarcely reacted with NaH2PO4. On the other hand, the decrease in H2PO4-sorption after removal of Al3+ indicated that some of the exchangeable Al reacted with NaH2PO4. These results were possibly due to the formation of ion pair like Al H2PO42+in the interlayer of smectite.
Thus, the above-mentioned contradictory reports can be explained by the fact that the reactivity of exchangeable Al with phosphate is strongly dependent on ionic species of phosphate.抄録全体を表示PDF形式でダウンロード (1046K) -
米田 哲朗, 大河原 正文, 多田 元彦1995 年 35 巻 1 号 p. 24-33
発行日: 1995/07/28
公開日: 2011/09/20
ジャーナル フリーVermiculitization of chlorite through weathering was studied in the Myoukurasawa landslide area by means of optical microscopy, X-ray diffractometry (XRD), electron microprobe method (EPMA), analytical transmission electron microscopy (ATEM) and infrared spectroscopy.
FeMg-chlorite widely occurs with mica clay mineral in primary Miocene sedimentary rocks in the Myoukurasawa landslide area. The chlorite in the altered zone around the slip surface of landslide was transformed partly to vermiculitic minerals. EPMA and ATEM analysis of the chlorite indicated that the FeO-and MgO-contents decrease but the SiO2-contents increase corresponding to the vermiculitization of chlorite. XRD analysis showed that the chlorite was transformed to two vermiculitic minerals: chlorite/vermiculite mixed-layer mineral evaluated to be of interstratification (g=1) with chlorite-layer percent of 60-70%, and low-charge vermiculite mineral. ATEM observations for the chlorite showed that particle size decreased corresponding to the chlorite transformation, and that the shape changed from polygonal particles to rounded ones correspondingly. It is considered that the slip surface was formed in chlorite-bearing rocks by early rock slide, and the late circulation of meteoric water facilitated the vermiculitization of chlorite in various degrees of transformation along the slip surface.抄録全体を表示PDF形式でダウンロード (9664K)
- |<
- <
- 1
- >
- >|