1959年噴出せる霧島火山群新燃岳火山灰中の硫黄化合物

概要

論文の詳細を見る
1. Chemical and mineralogical analyses showed that the Shimmoe ash specimens contain considerable amounts of water-soluble calcium sulfate, ferrous iron ions, native sulfur and pyrite crystals. Of water-soluble matter, calcium sulfate is a dominant component corresponding to 60〜85 per cent of total solids. Such a high content of water-soluble matter is unusual for magmatic ash, indicating that the ash had been subjected to diagenetic processes in the crater lake. Furthermore, the secondary origin of the ash may also be explained by the facts that ash contains approximately 20 per cent of very fine particles (less than 2 microns in equivalent spherical diameter), and that a majority of primary mineral grains, with the exception of flat glass fragments, are round in shape. 2. Microscopic examination and differential thermal analysis of the ash specimens showed that a greater part of pyrite crystals and native sulfur are found in the finer fraction (less than 20 microns in e. s. d.). X-ray diffraction patterns of pyrite crystals indicated that characteristic diffraction lines of pyrite could be detected, whereas the 1.76 KX line of marcasite could not be recognized, and that with the lapse of time a part of pyrite crystals has been oxidized to ferrous sulfate heptahydrate. 3. As a result of field and laboratory examinations it has been observed that the oxidation of native sulfur and pyrite crystals led to the production of sulfuric acid, and decreased the pH values of the ash deposits to such an extent as to become harmful to crops such as sweet potatoes, soy-beans, corns and rice plants.
日本ペドロジー学会の論文
1959-12-30

1959年噴出せる霧島火山群新燃岳火山灰中の硫黄化合物

スポンサーリンク

概要

著者

関連論文

スポンサーリンク