Medium P/T metamorphism in a subduction zone: A new type of regional metamorphism in Japanese accretionary complexes, inferred from b cell dimension of potassic white mica

Soichi Osozawa, Toru Koitabashi, Seiko Katsube, Martin Flower

研究成果: Chapter

2 被引用数 (Scopus)

抄録

Illite crystallinity (IC) and b cell dimension from potassic white mica have been measured for accreted metapelites found in Japanese accretionary complexes. From metamorphic mineral assemblages, some accreted high-grade metamorphic rocks are the high pressure/temperature (P/T) type. Because subduction zones are areas of relatively high pressures at low temperatures, it is reasonable to expect such high P/T rocks to develop. Our data show however, that not all the accreted rocks are of the high P/T type, but also include medium P/T rocks. This baric type is independent to the classification of accretionary complexes; coherent versus mixed, pure shear versus simple shear, but depends on the division without pelagite. Such a low and medium P/T regime is also evidenced by mineral assemblages in accreted basalts and is unrelated to the contact metamorphism. The medium P/T metamorphism is considered to be due to the thermal effect of a spreading mid-ocean ridge that is subducting under an island arc, and is a new type of regional metamorphism previously unknown.

本文言語English
ホスト出版物のタイトルStructural Geology
ホスト出版物のサブタイトルNew Research
出版社Nova Science Publishers, Inc.
ページ1-20
ページ数20
ISBN(印刷版)9781604568271
出版ステータスPublished - 2008 12月 1

ASJC Scopus subject areas

  • 地球惑星科学(全般)

フィンガープリント

「Medium P/T metamorphism in a subduction zone: A new type of regional metamorphism in Japanese accretionary complexes, inferred from b cell dimension of potassic white mica」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル