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Volume 62, Issue 1
Displaying 1-5 of 5 articles from this issue
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Tadashi Fujinuki, Toshio Igarashi1969 Volume 62 Issue 1 Pages 1-17
Published: July 05, 1969
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSDTA, thermogravimetric and chemical analyses of aragonites consisting of coral, as well as of organic origin have shown that only the aragonites in the hexacollara species contain the water, which is not expelled at temperatures less than about 280°C. This type of water in aragonite has not been reported previously and caused a problem as to the position and the type of bording in the structure of aragonite.
Although no final conclusion was reached in this study, possible orgion for this water is considered to be one of the following three; i. e. (a) water derived from hydrocalcite (b) freely mobile water molecules in the structure of aragonites, and (c) water contained in the hard tissues of corals.View full abstractDownload PDF (607K) -
Tsuneo Kitai1969 Volume 62 Issue 1 Pages 18-35
Published: July 05, 1969
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSThe petrographic description of the basic and intermediate plutonic rocks from Goto Islands and Tsushima Island in southwestern Japan is given in this report, with special attention to the optical properties and chemical compositions of the pyroxenes and the feldspars.
The calcium concentration between the coexisting plagioclase and clinopyroxene is discussed on the basis of the petrographic facts and experimental petrology. As the result, the content of H2O molecule in magma seems to be very significant for the distribution of calcium between the two minerals.View full abstractDownload PDF (808K) -
Hiroo Kagami1969 Volume 62 Issue 1 Pages 36-43
Published: July 05, 1969
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSIt has been generally received that the granites having relatively high initial strontium composition (initial Sr87/Sr86) were formed either by remelting of sialic crustal rocks or by contamination of crystal materials in magmas of mantle-type materials origin. However, it seems to be necessary to reexamine such an idea.
In the present paper the writer proposes a model for deriving granites having high initial strontium composition, without the participation of sialic crystral materials. In this model it is conceived that magmas generated from the upper mantle materials with low Rb/Sr and low Sr87/Sr86 values are brought to a halt there or nearby deep place for such a long time as 107yrs. or longer, and then are invaded into the crust and are differentiated into various granites. It is hoped that the validity of the above conception may be examined by further studies.View full abstractDownload PDF (923K) -
Susumu Nishimura, Kyozo Katsura1969 Volume 62 Issue 1 Pages 44-49
Published: July 05, 1969
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSThe distributions of uranium, thorium and potassium content are traced in Rokko granitic bodies. These radio-elements determined have a tendency to concentrate in coarse-grained biotite granite than fine-grained, especially as to uranium.
The following data are obtained: Rokko granite, 2.8ppm U; 10.1ppm Th; and 2.5% K: Nunobiki granodiorite, 1.8ppm U; 6.2ppm Th; and 1.4% K: Liparite, 2.2ppm U; 6.0ppm Th; and 3.1% K.View full abstractDownload PDF (222K) -
Kyozo Katsura, Susumu Nishimura1969 Volume 62 Issue 1 Pages 50-53
Published: July 05, 1969
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSThis is the second report treating the distribution of uranium, thorium and potassium content in granitic bodies. The results showed such a tendency that uranium and thorium concentrate towards the periphery of the intrusive mass.
The following data are obtained: Kumotani granitic bodies, 3.3ppm U; 10.4ppm Th; and 2.6% K: Mihama granite, 4.4ppm U; 11.6ppm Th; and 3.0% K.View full abstractDownload PDF (160K)
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