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Title Transcription
オキ ドウゴ ユイ ナガオダ チイキ ニオケル グンソウ ト オモスソウ ノ カザンガンルイ ノ ガンセキ キサイ ト ゼンガン K AR ネンダイ
Title Alternative (English)
Petrography and K-Ar ages of volcanic rocks from the early Miocene Kori Formation and the latest Miocene Omosu Formation in the Yui-Nagooda area, Oki-Dogo Island, SW Japan
File
language
jpn
Author
Sawada, Yoshihiro
Al-Jairani, Ashraf
Yamasaki, Hirofumi
Nagao, Keisuke
Description
The volcanic rocks of the early Miocene Kori Formation and the latest Miocene Omosu Formation are distributed in the Yui area, western part of Oki-Dogo Island. The Kori Formation consists of conglomerate, sandstone and siltstone intercalated with basalt, basaltic andesite and andesite lavas and sheets. Most of these volcanic rocks are subalkaline(arc tholeiitic). The volcanic rocks of the Omosu Formation is composed of shoshonite, rhyolite and trachyte lava and sheet with pyroclastic rocks. In the contrast with the volcanic rocks of the Kori Formation, the volcanic rocks of the Omosu Formation are characteristic of alkaline suite. This paper presents geology, petrography and K-Ar whole rock ages of the volcanic rocks of these formations. The volcanic rocks of the Kori Formation yielded K-Ar whole rock ages of 20.1±1.0Ma to 18.2±1.0Ma. The volcanic rocks of the Omosu Formation yielded whole rock K-Ar ages of 5.53±0.29Ma and 5.40±0.28Ma. These ages are consistent with the ages previously reported. The characters of volcanic activity changed from subalkaline and arc type in the early Miocene to alkaline and within plate(plume)type in the latest Miocene with hiatus of igneous activity during middle Miocene.
Journal Title
島根大学地球資源環境学研究報告
Volume
27
Start Page
1
End Page
9
ISSN
13439774
Published Date
2008-12-25
NCID
AA11455176
DOI(SelfDOI)
Publisher
島根大学総合理工学部地球資源環境学教室
Publisher Aalternative
Department of Geoscience, Interdisciplinary Faculty of Science and Engineering, Shimane University
NII Type
Departmental Bulletin Paper
Format
PDF
Text Version
出版社版
OAI-PMH Set
Interdisciplinary Graduate School of Science and Engineering
Remark
12-14,16+ / 1993+
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