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Volume 5 (1971)
- Issue 4 Pages 151-
- Issue 3 Pages 113-
- Issue 2 Pages 57-
- Issue 1 Pages 1-
Volume 5, Issue 1
Displaying 1-4 of 4 articles from this issue
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Masana Morioka, Kunihiko Kigoshi, Seiya Uyeda1971 Volume 5 Issue 1 Pages 1-6
Published: 1971
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSNeutron activation analysis of uranium, thorium and potassium has been. made on St. Paul's rocks of possible oceanic mantle origin. Results of analysis showed that average values of WISEMAN's “challengerite” are (15.8 ± 0.5) × 10-8 gU/g, (34.5 ± 1.0) × 10-8 gTh/g and (3100 ± 60) × 10-6 gK/g, giving a rate of heat production of ca. 300 × 10-16 cal/cm3·sec. This value agrees with the rate expected for the pyrolitic oceanic upper mantle. Other types of St. Paul's rocks, such as “owenites”, “paulites” and “questites” were shown to contain these elements comparable in amount with peridotite nodules. The Th/U ratio of these rocks, however, is unusually low.View full abstractDownload PDF (2777K) -
Oxygen isotopic studies of silicate minerals with special reference to hydrothermal mineral depositsRyuichi Sugisaki, Mead L. Jensen1971 Volume 5 Issue 1 Pages 7-21
Published: 1971
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSOxygen isotopic compositions of various silicate minerals of sedimentary and igneous origins have been investigated. The determined δ18O values of these hydrothermal silicates vary between -3 and +30‰ most of them correlate well with the crystallization temperature. The δ values of hydrothermal solutions (δW) from which quartz had been deposited have been calculated. The values thus calculated for samples which crystallized at temperatures above 300°C show a samll variation about a mean value of +8‰ and decrease systematically with temperature below 300°C. An ore fluid that existed above 300°C is interpreted as having equilibrated with a large reservoir of silicate rocks at high temperatures on the basis of 18O content. The variations of δW with temperature for samples which crystallized below 300°C are attributed to the mixing of the ore fluid with 18O-poor meteoric water. This view supports the cooling mechanism of hydrothermal ore fluids, which was proposed by BARTON and TOULMIN (1961). Hydrothermal solutions of ore deposits of shallow, so-called “subvolcanic” origin, however contain large proportions of meteoric water. The isotopic composition of the initial hydrothermal solution can be measured directly only in fluid inclusions in minerals deposited above 300°C and with no oxygen atoms. When ore deposits are classified, the separation of the group of deposits as “volcanic” or “subvolcanic” is helpful.View full abstractDownload PDF (7090K) -
Katsumi Yanagi, Tadashiro Koyama1971 Volume 5 Issue 1 Pages 23-37
Published: 1971
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSThirty to 100 liters of sea water sample containing MgCO3 powder was filtered through a glass fiber filter in order to collect particulate matter. Soon after the filtration, this glass fiber filter was kept in a deep freezer (-20°C) for later use. The following pigment analysis was carried out within a week. Plant pigments in the collected particulate matter were extracted with 90% acetone in a dark refrigerator. Pigments in the acetone extract were separated by thin layer chromatography using a mixture of cellulose powder and soluble starch as an adsorbent. The developing solvent was 1.2% n-propanol in petroleum ether. According to this procedure, 9 kinds of pigments were fractionated. Each of the fractionated pigments was eluted with 90% acetone and determined by measuring fluorescence of the acetone extracts after acidification with a small amount of hydrochloric acid. The analyses of sea water samples from the central Pacific showed the following facts: (1) Vertical distribution of chlorophyll a had a peak at a depth of 100m or 150m and its amount remarkably decreased with depth in parallel with the total pigments. (2) The percentage of chlorophyll a in the total pigments was more than 60% for the sea water samples examined, even at the depth of 1, 000m. (3) The absence of phaeophytin a was made clear for the samples examined.View full abstractDownload PDF (7235K) -
Toshiko Akiyama1971 Volume 5 Issue 1 Pages 39-56
Published: 1971
Released on J-STAGE: April 08, 2008
JOURNAL FREE ACCESSThe size distribution and the aggregation state of particulate organic matter and particulate iron were microscopically observed by the application of histological dyeing method. They were seriously affected by the seasonal water circulation in Lake Haruna. From the results, the formation and the change of particulate iron were suggested. Iron-organic aggregates were observed both in the lake and in the sea, and the significance of their distribution was discussed in relation to the sedimentation of iron and the formation of organic aggregates.View full abstractDownload PDF (8678K)
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