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Volume 62 (1969)
- Issue 6 Pages 311-
- Issue 5 Pages 275-
- Issue 4 Pages 223-
- Issue 3 Pages 177-
- Issue 2 Pages 55-
- Issue 1 Pages 1-
Volume 62, Issue 2
Displaying 1-4 of 4 articles from this issue
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Shiro Moriya1969 Volume 62 Issue 2 Pages 55-65
Published: August 05, 1969
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSSanriku coast area is chiefly composed of Mesozoic volcanic rocks with small amounts of black shale and sandstone.
The metamorphic effect is most evident in rocks consisting of mafic volcanic rocks.
On the basis of the characteristic distribution of metamorphic minerals such as prehnite, pumpellyite, chlorite, actinolite, and biotite, the low-grade metamorphic rocks in the Sanriku coast can be divided into the following three zones representing a progressive mineralogical changes.
Zone A; It has an assemblage of prehnite-pumpellyite, but actinolite is not commonly found.
Zone B; It has an assemblage of actinolite-chlorite, but pumpellyite is not stable.
Zone C; It has an assemblage of biotite-chlorite, but actinolite is partly stable.
So, it may be indicated that Sanriku coast area has the metamorphic facies series from prehnite-pumpellyite metagraywacke facies, to greenschist facies, but zeolite facies is not observed.View full abstractDownload PDF (505K) -
Yoshimasu Kuroda1969 Volume 62 Issue 2 Pages 66-79
Published: August 05, 1969
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSOlivine with well-developed cleavages on (100), (010) and (001) crystal planes has been found in some dunite bodies in Japan and its mineralogical meaning has been discussed (Kuroda and Shimoda, 1967; 1969). Here, the foregoing crystal models and discussion are critically summarized and new crystal structure-model for the cleavable olivine is dresented (Table 1, column 6; Fig. 4), This model well explains the observed intensities of X-ray powder diffraction of the cleavable olivine. Considering the minute differences of crystal structure (structure factor) among olivines with various origins, the differences of observed intensities of x-ray powder diffraction of such olivine are also well explained. The minute change of crystal structure of olivine is considered from the nature of chemical bonds, especially between MgII and O (Figs. 7, 8). Under the condition of high pressure chemical bond may show more covalent character and under the condition of low pressure and high temperature it may show more ionic character. The nature of chemical bonds may not be complied quickly as contraction or expansion of volume with new P-T condition, so the dimension of unit cell is not so different. Consideration on the interatomic distances is well discussed and other crystal chemical problems on olvine are also discussed.View full abstractDownload PDF (654K) -
KATSUTOSHI TOMITA, HIROYUKI YAMASHITA, NOBORU OBA1969 Volume 62 Issue 2 Pages 80-89
Published: August 05, 1969
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSIn this study we used volcanic glass from Kagoshima. In the system of glass+NaOH, initial crystallization of the sodium form of chabazite occurs, followed by a gradual conversion to zeolite X, and finally Na-P zeolite begins to crystallize.
In the system of glass+KOH, the potassium form of chabazite was formed after boiling for 14 hours.
High structure form of albite was formed from the _??_odium form of chabazite upon heating at 530°C and the potassium form of chabazite was borken upon heating at 1000°C.
There is replacement of the type Ca_??_Na2_??_K2 in chabazitc.View full abstractDownload PDF (384K) -
KYOZO KATSURA, SUSUMU NISHIMURA, SHINJIRO YAGI, ZIN'ITIRO HATUDA, TETS ...1969 Volume 62 Issue 2 Pages 90-102
Published: August 05, 1969
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESS
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