Geological reports of Shimane University

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Geological reports of Shimane University 5
1986-06-30 発行


Volcanic vent of the Miocene andesite in south of Matsue City
Inoue, Tatsuo
The purpose of this report is to describe a newly discovered volcanic vent. The vent crupted in unconsolidiated gravel layer in Early Miocene time. It is surrounded by Paleogene biotite granite, and is filled with andesite lapilli tuffs and lava blocks, fragments of granite derived from the vent wall, and a small quantity of pebbles. The structure which is pipe-shaped is oval in plane a, nd its major diameter of about 240m is
oriented north-south.