- 著者
-
水上 知行
- 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.31, no.2, pp.87-96, 2001 (Released:2008-05-08)
- 参考文献数
- 25
- 被引用文献数
-
3
4
The Sugashima ultramafic mass is one of the largest ultramafic bodies in the Mikabu belt, and is composed of a hornblende-poor part (Unit I) and a hornblende-rich part (Unit II). Unit I is a layered complex with laminar and convoluted structures probably formed as a crystal mush. Detailed petrographic studies reveal that orthopyroxene exists in almost all the rock types forming the igneous layering of Unit I: dunite, plagioclase wehrlite and olivine gabbro. Orthopyroxene crystals commonly occur adjacent to olivine crystals and locally show poikilitic textures enclosing olivine grains with rounded or irregular shapes, indicating their peritectic growth from a basaltic magma at a pressure lower than 0.9 GPa.