Orthopyroxene and compositional layering in the Sugashima Ultramafic Mass, Mikabu belt

  • MIZUKAMI Tomoyuki
    Department of Geology and Mineralogy, Graduate School of Science, Kyoto University Present Address: Division of Earth and Environmental Science, Graduate School of Environmental Studies, Nagoya University

Bibliographic Information

Other Title
  • ミカブ帯菅島超苦鉄質岩体の斜方輝石の産状と組成層状構造
  • ミカブタイ スガシマ チョウ クテツ シツガンタイ ノ シャホウ キセキ ノ サンジョウ ト ソセイ ソウジョウ コウゾウ

Search this article

Abstract

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.<br> 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.

Journal

Citations (2)*help

See more

References(31)*help

See more

Details 詳細情報について

Report a problem

Back to top