北海道西胆振地域の新第三系中に産出する方沸石 : ワイラカイト系沸石の鉱物学的性質

概要

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Analcime is found as an alteration product in diagenetically and hydrothermally altered rocks. Wairakite and analcime-wairakite solid solution occur commonly in the geothermal area. Analcime - wairakite series minerals which are analcime, wairakite and minerals having the intermediate chemical compositions occur in the Neogene system of the Nishi-Iburi district, southwest Hokkaido. In this paper, the mineralogical properties such as refractive indices, chemical composition, X-ray data and morphology are described. The wairakites in boring cores increase in Δ2θ(2θ_<(004)>-2θ_<(400)>) with increasing depth and temperature. This fact shows that Al/Si ordering of wairakite proceeds with a rise in temperature. Na_2O/CaO ratio of the analcime -wairakite series minerals decreases with burial depth. The plot of the minerals in natrolite -wairakite- albite triangle diagram indicates that vacant immisicibility area in analcime-wairakite solid solution seems to be narrower than previous data.
日本粘土学会の論文
1990-04-24