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Volume 69, Issue 7
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WITH SPECIAL REFERENCE TO THE MINERALOGICAL PROPERTIES OF SUDOITE AND TOSUDITEKeiji Kimbara, Hiroshi Nagata1974 Volume 69 Issue 7 Pages 239-254
Published: July 05, 1974
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSThe aluminian clay minerals, “sudoite and tosudite, ” sericite, interstratified sericite-montmorillonite, kaolinite and montmorillonite occur in the core samples from the altered zone of the Kuroko-type deposit at Niida, Akita Prefecture, northeast Japan. In drill-hole #445, the di. trioctahedral chlorite, sudoite, occurs dominantly in the black-ore zone (baritepyrite). On the other hand, in drill-hole #457, the magnesium-bearing aluminian interstratified chlorite-montmorillonite, “tosudite, ” was found in the gypsum zone (gypsum-anhydrite-pyrite). In the drill-hole #445, sericite occurs only in the brecciated rhyolite under the black-ore whereas interstratified sericite-montmorillonite was found in the fine tuff above the black-ore. Kaolinite was found locally in the tuff above the gypsum zone of the drill-hole #457. Mineralogical properties of these clay minerals, especially of sudoite and tosudite, are discussed in this paper.View full abstractDownload PDF (1428K) -
Kiyoshi Ishibashi1974 Volume 69 Issue 7 Pages 255-266
Published: July 05, 1974
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSSeveral kinds of amygdale minerals are found in the Higashi-matsuura basalts near Karatsu city, Saga Prefecture. The mineral paragenesis of twenty eight localities is listed. Among the localities, the chabazite and calcite are the most common minerals in this area. Although some other zeolites and clay minerals are observed in several druses. The crystallization sequence of the amygdale minerals is manifest according to the overgrowth of several minerals from the wall of the cavities towards the center. At first calcite and chabazite are crystallized and then herscherite, thomsonite and natrolite follow and next β-sepiolite, talc and nontronite are formed. At last illite, montmorillonite and halloysite are crystallized.
New chemical analyses of calcite, Mn-calcite, chabazite, herscherite, thomsonite, natrolite, β-sepiolite and halloysite as well as optical properties and x-ray data are presented. Some discussions concerning the chemical composition of host rocks and their zeolites are made in this paper.View full abstractDownload PDF (1199K) -
Satoshi Tomonari1974 Volume 69 Issue 7 Pages 267-273
Published: July 05, 1974
Released on J-STAGE: August 07, 2008
JOURNAL FREE ACCESSIn the central part of Chugoku Province, several types of granitic rocks, presumably of Late-Mesozoic are widely distributed. The granitic rocks in the Fuchu District have been hitherto divided into two types, namely, the Hiroshima granitic complex and the Central plutonic complex. Furthermore, the granites belonging to the latter have been divided into three groups; those of the older, the younger, and the unknown ages. Detailed classification and the relationship among these granitic rocks in the Fuchu District have been left unsolved. From the standpoint of petrographical features such as color of potash-feldspar, volume ratio of minerals, chemical composition and occurrence of xenoliths and dyke rocks, granitic rocks of the district can be divided into four types of complex as follows:
(1) Mannari type (2) Ashida type
(3) Hirotani type (4) Mikawa type
The Mannari type granite belongs to the Central plutonic complex, and the other types to the Hiroshima granitic complex according to the current classification. The Ashida and the Mikawa type granites can be divided into those of coarse, medium, and fine grained ones and the Mannari type granite into coarse and fine members. The Mannari type granite has been intruded by the Mikawa and Ashida type. From the field evidences, the Ashida, the Hirotani, and the Mikawa types are considered to be nearly of the same age. Therefore, the Mannari tvpe granite is thought to be the oldest among these four types.View full abstractDownload PDF (1127K)
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