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Volume 17 (1983)
- Issue 6 Pages 269-
- Issue 5 Pages 223-
- Issue 4 Pages 165-
- Issue 3 Pages 111-
- Issue 2 Pages 63-
- Issue 1 Pages 1-
Volume 17, Issue 2
Displaying 1-5 of 5 articles from this issue
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L. A. Burchfield, P. K. Kuroda1983 Volume 17 Issue 2 Pages 63-70
Published: April 20, 1983
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSThe concentrations of 89Sr and 90Sr in a total of 117 samples of individual rain and snow collected at Fayetteville (36°N, 94°W), Arkansas, were determined radiochemically during the period between September 1979 and August 1981. A spectacular increase in the concentration of 90Sr in the atmospheric precipitation was observed during the month of March 1981, approximately 5 months after the 25th Chinese nuclear test of 16 Octuber 1980. A complicated pattern of variation of the 89Sr/90Sr ratio in rain observed after this nuclear explosion is interpreted in terms of the general theory of radioactive fallout based on the two-compartment model of the atmosphere, taking into consideration the fact that the nuclear debris released into the atmosphere at Lop Nor (40°N, 90°E), China, is known to travel eastward and circle the world more than once.View full abstractDownload PDF (1927K) -
Yasuyuki Muramatsu1983 Volume 17 Issue 2 Pages 71-86
Published: April 20, 1983
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSFifteen major components and 21 trace elements (Li, F, S, Cl, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Cd, Ba, Hg, Tl, Pb and Bi) were analyzed for 11 kimberlites and 3 xenoliths (garnet peridotite, eclogite and gabbro) from South Africa. Selected major and trace element contents of olivine, serpentine, pyroxene, phlogopite, perovskite, spinel, magnetite, Fe-Ni-Cu-S ores and native copper in several kimberlites were also measured. Sulfur isotope compositions of 5 kimberlites and a garnet peridotite range from δ34S -3 to +9.6‰. The concentrations of major elements and Cr, Co, Ni, Zn, Hg have a small, but those of Li, Na, K, Rb, Cl and Tl a wide range of variation. Good correlations of K-Rb have to be mentioned. Large Fe2O3/FeO ratios indicate relatively high oxygen fugacities during eruption. Additional data on about 60 elements in bulk kimberlites have been compiled from the literature to estimate the average chemical composition of kimberlites. In order to know the accumulation and depletion of elements during magma formation, the elemental abundances of kimberlites were compared with those of undepleted mantle rocks. Kimberlites are characterized by very high concentrations of incompatible and volatile elements such as La, Ce, C, Nd, Th, U, F, Cs, Nb, Sm, Ta, Rb, Ba, K, P, Pb and Sr, and low concentrations of Si, Na, Al and heavy REE. Concentrations of the former elements suggest that kimberlite magmas are produced by a small degree of partial melting in the presence of CO2 and H2O under upper mantle conditions.View full abstractDownload PDF (4050K) -
Kazuhiko Kano1983 Volume 17 Issue 2 Pages 87-93
Published: April 20, 1983
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSOpal-CT in sediments is formed from opal-A and is converted to quartz during diagenesis. In that process, opal-CT becomes progressively ordered as is distinctly indicated by the decrease in d(101) spacing. Based on a kinetic equation experimentally found by KANO (1979) and KANO and TAGUCHI (1982), the decreasing rate of d(101) spacing has been calculated from previously reported d(101) spacings (MITSUI, 1975) and thermal history of sediments in a borehole, MITI Hamayuchi. The calculated rate makes a subtle difference between the reported and calculated d(101) spacings, suggesting the availability of the equation applied. However, even if compared at the same temperature, the rate is much slower than that in hydrothermal alkaline conditions. Thus, the ordering process of opal-CT is more or less chemically controlled. Taking the thermal history of sediments into account, a model based on the kinetic equation well fits the previously reported relationship between the d(101) spacing of Neogene siliceous sediments and the maximum temperature to which the sediments have been subjected (IIMIMA and TADA, 1981), suggesting that the ordering process of opal-CT in diagenetic conditions is controlled mainly by temperature. The features of distribution of d(101) spacing in sediment piles have been discussed by using the model.View full abstractDownload PDF (1988K) -
Shuichi Watanabe, Kazunobu Mishima, Sadao Matsuo1983 Volume 17 Issue 2 Pages 95-104
Published: April 20, 1983
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSCarbon dioxide and graphitic carbon in olivine crystals from dunite nodules in the 1801 lava flow of the Hualalai Volcano, Hawaii were extracted by three methods, i.e., the pyrolysis under oxygen atmosphere, the ball-milling and the dissolution with hydrochloric acid. It is concluded that most of CO2 extracted by the oxidative pyrolysis was derived from fluid inclusions, by comparing the isotopic ratios of CO2 released by the oxidative pyrolysis and the ball-milling. Graphitic carbon was recovered from the evaporation residue after olivine crystals were dissolved in hydrochloric acid. The averaged concentration of CO2 extracted by the oxidative pyrolysis was 0.87μmole/g and δ13C value was -3.2‰. These of graphitic carbon were 0.51μmole/g and -26.9‰, respectively, No appreciable amount of hydrogen-bearing species such as H2, H2O, CH4, higher hydrocarbons and H2S was detected in olivine crystals by both the oxidative pyrolysis and the ball-milling. Assuming all the extracted carbon is present in fluid inclusions in olivine crystals and the disproportionation reaction of CO (2CO → CO2 + C) has occurred in inclusions, we conclude that the major carbon-bearing species in the mantle beneath the Hawaiian Islands are CO and CO2, and the CO/CO2 ratio is estimated to be about 3 on the basis of the experimental data and that the δ13C value of the carbon in upper mantle below the Hawaiian Islands is around -12‰. Some additional data on Japanese olivines suggest that the δ13C value of the mantle carbon may not be unique throughout the mantle.View full abstractDownload PDF (3848K) -
Minoru Okumura, Yasushi Kitano, Masatoshi Idogaki1983 Volume 17 Issue 2 Pages 105-110
Published: April 20, 1983
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSThe authors show the removal of fluoride, chloride, sulfate, phosphate, borate ions and soluble silica from seawater by marine carbonate sedimentation. The authors have estimated the amounts of anions and soluble silica discharged into seawater and those of anions and soluble silica removed from seawater by marine carbonate sedimentation. The balance between both amounts estimated indicates that the significant portions of fluoride, phosphate and borate ions discharged into seawater are removed from seawater by marine carbonate sedimentation.View full abstractDownload PDF (1727K)
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