著者

森下 篤史 西田 憲正

出版者

日経BP社

雑誌

日経ベンチャ- (ISSN:02896516)

巻号頁・発行日

no.248, pp.74-77, 2005-05

---

経営者としての己に喝を入れるべく、「社長記者」として武者修業中のテンポスバスターズの社長、森下篤史。今回は、東横イン(東京・大田区)の西田憲正社長の元に、「頼もう!」とばかりに乗り込んだ。東横インは、子育てを終えた地元の主婦をホテルの支配人として採用し、急成長している企業である。本社の社員約720名の中で、男の正社員は30人程しかいない。

著者

木股 三善 西田 憲正 村上 英樹

出版者

一般社団法人 日本鉱物科学会

雑誌

鉱物学雜誌 (ISSN:04541146)

巻号頁・発行日

vol.23, no.2, pp.45-58, 1994-04-30 (Released:2009-08-11)

参考文献数

91

被引用文献数

1 1

---

This paper reviews on crystal chemistry of plagioclases and geochemical roles of their megacrysts including native coppers and hydrocarbons, discussed in two parts.Part I. Structural classification of feldspar compositions can be allocated into four types; feldspar, paracelsian, hexacelsian and hollandite structures. Though the phase relation between the first and the second types has been open to question, recent probing of their isotropic temperature factors and bond-valence theory to the M-sites intensifies that feldspars are in the wide stability field from low to high temperatures under low pressures, and that high pressure and low pressure are the preference field for paracelsians. Though very common in north-east part of Japanese island and Izu-Bonin arcs, anorthite megacrysts have never been found in other districts in Japan and have been rare in world-wide occurrences. Native coppers, verified by chemical shift method of EPMA and X-ray microdiffraction, are found to be included by anorthite megacrysts from Japanese island arc and by labradorite ones from the continental margin of North America. These anorthites in the basaltic lavas are of approximately 1 to 3 cm size and often contain several corroded Mg-olivines scattering as single crytals less than a few mm long. The plagioclase megacrysts show no chemical zoning, but the anorthites with the Al/Si ordered state have partings developed in places whereas the labradorites are of the AUSi disordered structure indicative of high temperature type. Each role in their plagioclase structure establishes Mg, Fe, Al and Si cations as a few minor endmembers of CaFeSi3O8, CaMgSi3O8, AlAl3SiO8 and_??_Si4O8 for the solid solutions. Furthermore micro-inclusions of native zinc, copper and brass scattering in the red-clouded anorthite megacryst frozen by the supercooling environment could have an implication for a precusor to Kuroko deposits. Review (1) discusses both structural tolerance of plagioclases and their megacrysts including native coppers.

著者

新田 恵理子 木股 三善 星野 美保子 越後 拓也 濱崎 聡志 篠原 宏志 西田 憲正 八田 珠郎 清水 雅浩

出版者

一般社団法人 日本鉱物科学会

雑誌

岩石鉱物科学 (ISSN:1345630X)

巻号頁・発行日

vol.35, no.6, pp.270-281, 2006 (Released:2007-03-15)

参考文献数

43

被引用文献数

1

---

High temperature volcanic sublimates including so-called “molybdenum blue” sampled around the high-temperature fumaroles at Iwodake volcano, Satsuma-Iwojima, Kyushu, Southwestern Japan, were characterized by X-ray powder diffraction, X-ray micro-diffraction, Raman micro-scattering, electron microprobe and X-ray photoelectron spectroscopic analyses. The identified minerals are molybdenite, sphalerite, tugarinovite, molybdite, hematite, halite, sylvite, anglesite, wulfenite, quartz, tridymite, cristbalite and potassium alum. Occurrences of both tugarinovite and molybdite are observed in Kudriavy volcano, too, and the coexistence of their minerals is characteristic of high-temperature volcanic sublimates. The molybdenite and sphalerite from Iwodake are exceedingly rich in Re (up to 0.77 wt%) and In (up to 1.69 wt%), respectively, distinguished from those of a different origin by chemical composition. The molybdenite consists of both of 3R and 2H1 polytypes. Sublimates from Iwodake and Kudriavy volcanoes are similar in mineralogy. Although the difference in the host rock arises between the Iwodake (rhyolite) and the Kudriavy (basaltic andesite) volcanoes, their volcanic gases resemble each other in F and Cl contents. This resemblance might cause the similarity in sublimate mineralogy between these volcanoes.

著者

龍 徹 木股 三善 西田 憲正 興野 純 清水 雅浩

出版者

一般社団法人 日本鉱物科学会

雑誌

岩石鉱物科学 (ISSN:1345630X)

巻号頁・発行日

vol.34, no.5, pp.242-251, 2005 (Released:2005-10-18)

参考文献数

27

被引用文献数

2 2

---

Chemical evolution of ferrocolumbites from the Ishikawa-yama granitic pegmatites, Fukushima, Japan, has been revealed by electron microprobe analysis. The compositions of ferrocolumbites are different among sample locations, which are within about 1 km distant from each other. Three discernible trends in compositional variations in ferrocolumbites have been observed: (1) a homogeneous crystal trend, with low Ta/(Ta + Nb); (2) a trend with oscillatory zoning related to Ta and Nb; (3) a trend with patchy zoning related to Fe and Mn. Oscillatory zoning of ferrocolumbite is intimately related to crystal growth in magmatic process. Ferrocolumbite with patchy zoning shows parallel extinction and doesn’t appear to have the complementary distribution of octahedral cations due to some coupled substitutions on the plots of partition coefficient (each zone/the assumed average) against ionic radius. These facts and the curved boundaries of patchy zoning suggest that patchy zoning of ferrocolumbite has been produced by topotaxy in the open system.