Two-pyroxene amphibolites in Dogo, Oki islands, Shimane-ken, Japan.
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- HOSHINO MITSUO
- Laboratory of Geology, College of General Education, Nagoya University
Bibliographic Information
- Other Title
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- 島根県隠岐島後の両輝石角閃岩
Abstract
The Oki metamorphic massif consists of pelitic gneiss, migmatitic gneiss, augen gneiss, amphibolite and calcareous gneiss, and this massif has a characteristic dome structure. Sillimanite and orthoclase are stable in the pelitic gneiss and this coexistence indicates the higher grade metamorphism.<br> Amphibolites can be divided into two groups:<br>(a) plagioclase-brown hornblende-clinopyroxene-orthopyroxene-quartz-ilmenite-pyrrhotite (-magnetite)<br>(b) plagioclase-brown hornblende-quartz-ilmenite (-clinopyroxene-magnetite).<br> Orthopyroxene bearing amphibolite (Group a) has higher FeO and SiO2 contents, higher FeO/(FeO+MgO) ratio and lower Fe2O3/(Fe2O3+FeO) ratio. Orthopyroxene is considered to be formed by the reaction of hornblende+quartz=orthopyroxene+clinopyroxene+plagioclase+water. In this reaction orthopyroxene can be easily formed under the Fe2+-rich environment.<br> Geological and petrographical evidences indicate that orthopyroxene-bearing amphibolite and orthopyroxene-free amphibolite are formed under same metamorphic condition, which is transitional from the amphibolite facies to the granulite facies.
Journal
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- The Journal of the Japanese Association of Mineralogists, Petrologists and Economic Geologists
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The Journal of the Japanese Association of Mineralogists, Petrologists and Economic Geologists 74 (3), 87-99, 1979
Japan Association of Mineralogical Sciences
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Details 詳細情報について
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- CRID
- 1390282681193142144
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- NII Article ID
- 130003728411
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- COI
- 1:CAS:528:DyaL3cXptFCh
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- ISSN
- 18830765
- 00214825
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- Text Lang
- en
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- Data Source
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- JaLC
- Crossref
- CiNii Articles
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- Abstract License Flag
- Disallowed