40Ar-39Ar analysis of phlogopite in the Horoman Peridotite Complex, Hokkaido, Japan and implications for its origin

フォーマット:

論文

責任表示:

Kaneoka, Ichiro ; Takahashi, Natsuko ; Arai, Shoji

言語:

英語

出版情報:

Blackwell Publishing, 2001-01-01

著者名:

• Kaneoka, Ichiro
• Takahashi, Natsuko
• Arai, Shoji

掲載情報:

Island Arc

ISSN:

1038-4871      

巻:

10

通号:

1

開始ページ:

22

終了ページ:

32

バージョン:

publisher

概要:

金沢大学理工研究域自然システム学系<br />40Ar-39Ar analysis of phlogopite separated from a plagioclase lherzolite of the Horoman Peridotite Complex, Hokkaido, Japan, has yielded a plateau age of 20.6 ± 0.5 Ma in an environment where the metamorp … hic fluid was characterized by an almost atmospheric Ar isotopic ratio. The age spectrum is slightly saddle-shaped, implying some incorporation of excess 40Ar during the formation of the phlogopite at a depth. As the phlogopite has been inferred to have formed in veins and/or interstitials during exhumation of the peridotite body, metasomatic fluids, to which ground- and sea water might have contributed, were probably involved in the formation of phlogopite in the crustal environment. A total 40Ar-39Ar age of 129 Ma of a whole rock sample of the plagioclase lherzolite, from which the phlogopite was separated and is representative of the main lithology of the Horoman Peridotite Complex, indicates the occurrence of excess 40Ar. Hence, the age has no geological meaning. 続きを見る

URL:

http://hdl.handle.net/2297/19562