open access

https://hdl.handle.net/2115/36732

The Takadomari Serpentinites in the Kamuikotan Ophiolite Belt, Hokkaido, Japan

英語

1985-08

Hokkaido University

Journal of the Faculty of Science, Hokkaido University. Series 4, Geology and mineralogy

21(3)

305-319

Within the Kamuikotan Ophiolite Belt, a large serpentinite mass more than 10×12 km is observed around Takadomari as a tectonic unit of dismembered ophiolite. The Takadomari serpentinites show an east-facing layered structure composed primarily of dunite, harzburgite, and olivine-orthopyroxenite layers. More than 120 dykes of microdiorite-microgabbro were found in the serpentinite mass and clearly show an intrusive relation. The serpentinization is characterized by a progressive crystallization of antigorite replacing lizardite and chrysotile serpentines crystallized retrogressively. The Takadomari mass is regarded as a dismembered ophiolite unit which is situated at the base of the Horokanai ophiolite complex. High pressure and low temperature type metamorphic rocks such as glaucophane schist are considered to be a tectonic unit lifted up by the Takadomari serpentinites.

紀要論文

Version of Record

0018-3474