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Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Science / Faculty of Science >
Journal of the Faculty of Science, Hokkaido University. Series 4, Geology and mineralogy >
Vol.XXI, No.4 >
Borosilicates (Datolite, Schorl) and Alumosilicates (Andalusite, Sillimanite) in the Oketo Rhyolite, Hokkaido
Title: | Borosilicates (Datolite, Schorl) and Alumosilicates (Andalusite, Sillimanite) in the Oketo Rhyolite, Hokkaido |
Authors: | Watanabe, Jun Browse this author | Hasegawa, Kiyoshi Browse this author |
Issue Date: | Feb-1986 |
Publisher: | 北海道大学 |
Journal Title: | 北海道大学理学部紀要 |
Journal Title(alt): | Journal of the Faculty of Science, Hokkaido University. Series 4, Geology and mineralogy |
Volume: | 21 |
Issue: | 4 |
Start Page: | 583 |
End Page: | 598 |
Abstract: | The second occurrence of datolite in Hokkaido, after the first report from the Furano mine (Sako et al., 1957; Sato et al., 1967), is herein described from the Oketo Rhyolite (Watanabe et al., 1981a, 1981b), Kitami Province, Hokkaido. Datolite from the Oketo Rhyolite occurs in the small veinlets cutting the metasomatic facies of the rhyolite of the Miocene intrusion. Optical data of the datolite are: α=1.625, β=1.652, γ=1.669. 2Vx=71.0-72.0°. Lattice constants are: a=9.62Å, b=7.60Å, c=4.83Å, c/a=0.50, β=90°11'. X-ray data is shown in Table 1. Chemical data are: Ca4.02B4.11Si3.90O15.96(OH)4.04 to Ca4.23B3.68Si4.11O15.93(OH)4.07 on the basis of 20(O, OH), namely as the empirical formula is given Ca1.00-1.06B1.03-0.92Si0.97-1.03O3.99-3.98(OH)1.01-1.02 for the formula of datolite; CaBSiO4(OH). The mineral is associated with dravite-schorl tourmaline including minor content of uvite molecule, andalusite and sillimanite with a very small quantity of fluorite and topaz, showing the mode of occurrence different quitely from any of the known cases in Japan and world. Also, some data of the associated minerals are presented. |
Type: | bulletin (article) |
URI: | http://hdl.handle.net/2115/36742 |
Appears in Collections: | Journal of the Faculty of Science, Hokkaido University. Series 4, Geology and mineralogy > Vol.XXI, No.4
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