著者

大森 啓一 岡田 広吉

出版者

一般社団法人 日本粘土学会

雑誌

粘土科学 (ISSN:04706455)

巻号頁・発行日

vol.18, no.2, pp.40-50, 1978-06-25 (Released:2011-09-20)

参考文献数

9

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An old castle named Tagajo was founded between the 8th and 11th Centuries in Miyage Prefecture, Japan. Roofing tiles were unearthed from the ruins of castle and old oven, which were studied by mineralogical methods.Roofing tiles used in the study were classified from archaeology into two groups, one of which was the I era tiles and the other the II, III and IV era tiles. Every tiles were 12 to 34mm in thickness. The I tiles were homogeneous with light dark color and the others inhomogeneous roughly with ashy color. In every tiles many porphyritic quartz crystals were found in association with plagioclase, hornblende, augite and magnetite under a microscope. Their groundmasses consisted of quartz and glassy materials.Textures were found to be fluidal, banded and microfolded in the I tiles, and were more notable than those of the II to IV tiles. From X-ray diffraction patterns the presence of quartz, plagioclase, cristobalite and mullite was detected. From chemical analyses all compositions concentrated on a small area centered at 70% SiO2, 20% Al203 and 10% the others in the triangle phase diagram. Refractorinesses of every tiles were found to be under SK 26. Water absorptions of these tiles satisfies a requirement of the JIS standard for roofing tiles.From these results it was found that the fired temperatures were between 1, 000° and 1, 200°C and the techniques making roofing tiles progressed from the I era to the II to IV eras.

著者

岡田 広吉 加藤 清一

出版者

一般社団法人 資源・素材学会

雑誌

日本鉱業会誌 (ISSN:03694194)

巻号頁・発行日

vol.92, no.1064, pp.685-688, 1976-10-25 (Released:2011-07-13)

参考文献数

24

著者

岡田 広吉

出版者

一般社団法人 資源・素材学会

雑誌

日本鉱業会誌 (ISSN:03694194)

巻号頁・発行日

vol.94, no.1086, pp.555-558, 1978-08-25 (Released:2011-07-13)

参考文献数

25

著者

岡田 広吉

出版者

社団法人 日本金属学会

雑誌

日本金属学会会報 (ISSN:00214426)

巻号頁・発行日

vol.13, no.9, pp.689-692, 1974-09-20 (Released:2011-08-10)

著者

南部 松夫 岡田 広吉

出版者

東北大學選鉱製錬研究所

雑誌

東北大學選鑛製錬研究所彙報 = Bulletin of the Research Institute of Mineral Dressing and Metallurgy, Tohoku University (ISSN:0040876X)

巻号頁・発行日

vol.19, no.1, pp.1-12, 1963-10-28

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The bedded manganese oxide deposits of Iwasaki distrct, Aomori Prefecture occur in most cases in tuffaceous sandstone of the upper Miocene age. The mother rock of these deposits is slightly affected by the hydrothermal alteration, and the ore is characterized by the mineral composition of a single manganese mineral, todorokite. The mineral is identified mainly by the X-ray powder method and chemical and differential thermal analyses. The chemical formula is (Mn^<2+>_<0.58> Ca_<0.09> Mg_<0.20> Ba_<0.04>)_<0.90> Mn^<4+>_<3.06> O_<7.00>・2.1 H_2O which agrees well with Mn^<2+>Mn_3^<4+>O_7・2-xH_2O given by L.T.Larsen in 1962.