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Volume 4 (1970 - 1971･･･
- Issue 4 Pages 157-
- Issue 3 Pages 93-
- Issue 2 Pages 53-
- Issue 1 Pages 1-
Volume 4, Issue 3
Displaying 1-5 of 5 articles from this issue
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Hiroji Honma, Hitoshi Sakai1971 Volume 4 Issue 3 Pages 93-103
Published: 1971
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSThe Koyama intrusive complex consists of varying rock-types from olivine pyroxenite to aplite as a consequence of differentiation of gabbroic magma. The whole-rock δ18O values of the main differentiates are +6.2 to +6.6‰ (in SMOW) for olivine rich members and are invariably around +7.8‰, from quartz gabbro to aplite. It is suggested that the Koyama magma differentiated without any significant isotopic fractionation. The isotopic difference between the two groups is largely due to the concentration into the former of olivine and pyroxenes which are isotopically lighter than plagioclase. The results support the view that the major rock-types are formed by the gravity sorting and accumulation of olivine, pyroxenes and plagioclase. Among the minor members of the complex, “granular” gabbro and a quartz diorite dyke are depleted in 18O by 2 to 3‰ compared to the major rock-types, whereas the veins of augite and of plagioclase-hornblende exhibit higher 18O content. It is suggested that a simple contamination of the residual magma by wall rock basalt can not produce such isotopic anomalies.View full abstractDownload PDF (5171K) -
Hisao Mabuchi, Reisuke Gensho, Yukio Wada, Hiroshi Hamaguchi1971 Volume 4 Issue 3 Pages 105-110
Published: 1971
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSThe production rates of 32P in rhombic sulfur were measured at various altitudes from sea level up to the top of Mt. Fuji. The production rate decreases exponentially with increasing atmospheric depth and the dependence indicates that neutron reaction is predominant in the 32P production. From an underground experiment, the contribution of muons to the production of 32P was estimated and the result was compared with relevant data.View full abstractDownload PDF (2509K) -
Takashi Matsumoto1971 Volume 4 Issue 3 Pages 111-121
Published: 1971
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSThe partitioning of Mg, Fe and Co between coexisting olivine and orthopyroxene found in peridotite inclusions is examined from the thermodynamic point of view, using a binary and a ternary regular solution models. The following two exchange reactions are considered: MgSi0.5O2+FeSiO3 = FeSi0.5O2 +MgSiO3 (1) and MgSi0.5O2+CoSiO3=CoSi0.5O2+MgSiO3. (2) The apparent partition coefficients are respectively: RT·lnK'Fe.Mg=-ΔG1-(2XMg01-1)(W01P+α01)+(2XopxMg-1)(WopxP+αopx) (3) and RT·lnK'Co.Mg=-ΔG2+(Δα+ΔWP)XFe (4) Using (3) and (4), we can estimate the P-T conditions at equilibrium of peridotite inclusions, if we know the numerical values of the apparent partition coefficients. Examination of the equilibrium relations in a peridotite inclusion from a South African kimberlite and in an lchiomegata lherzolite leads to the conclusion that the garnet peridotite is formed at higher pressure and lower temperature than the lherzolite.View full abstractDownload PDF (4491K) -
Kikuo Terada, Susumu Osaki, Shunso Ishihara, Toshiyasu Kiba1971 Volume 4 Issue 3 Pages 123-141
Published: 1971
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSThe rhenium contents of about 200 molybdenites have been determined by the neutron-activation or the catalytic spectrophotometric analyses. The present authors developed these methodes for the determination of the rhenium content of a very wide range, taking only a small amount of each sample. The data obtained show that 1) the rhenium content of molybdenite covers the range from 10-8 to 7 × 10-3 in atomic ratio of Re/Mo, 2) the rhenium contents generally decrease with the following order of occurrence of the molybdenites: volcanic sublimate, porphyry copper deposits, contact-metasomatic deposits, disseminated deposits and quartz veins, 3) as far as plutonic type of molybdenites are concerned, rhenium increases generally with decrease in estimated temperature of molybdenite deposition, 4) the rhenium contents of the molybdenites from Daito area, Shimane Prefecture.as a whole are contrary to the above rule and are higher than those from similar deposits in other areas, 5) low rhenium contents are found in cavity molybdenites, 6) rhenium in an euhedral crystal of molybdenite shows a regular distribution which obeys the Doerner-Hoskins' law, indicating that rhenium forms a solid solution with molybdenum.View full abstractDownload PDF (7441K) -
Tetsuo Fujita1971 Volume 4 Issue 3 Pages 143-156
Published: 1971
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSPlankton samples collected in coastal and offshore areas around Japan were analyzed for sodium, potassium, calcium, magnesium, phosphorus and silicon. Zooplankton samples of single or mixed species were used in the experiment, while phytoplankton samples were only of mixed species. Species composition of mixed samples were determined under a microscope. Generally, phytoplankton are much higher in potassium and silicon contents than zooplankton, while zooplankton are higher in sodium and phosphorus contents than phytoplankton. Magnesium and calcium are relatively abundant in the samples of phytoplankton. A correlation was seen between potassium and sodium contents, calcium and magnesium contents and phosphorus and silicon contents of zooplankton and of phytoplankton. The K/Na ratio of phytoplankton is exceedingly higher than that of zooplankton or seaweeds, while the P/Si ratio of phytoplankton is particularly lower than that of zooplankton or seaweed. On the other hand, the values of Ca/Mg ratio of zooplankton, phytoplankton and seaweeds are very close to each other.View full abstractDownload PDF (6103K)
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