済州島火山の地質学的・岩石学的・古磁気学的性格

抄録

The Cheju Island, southern Korea is covered by alkaline volcanic rocks of Pliocene and Pleistocene which are divided into three groups, i.e. trachytes, trachyandesites, and trachybasalts in order of eruption epoch. The trachytes are characterized by aegirineaugite, kaersutite-ike amphibole, Fa-rich olivine and plagioclase with anorthoclase mantle. The trachyandesites show the reversed magnetic polarity which belongs perhaps to the “MATUYAMA reversed epoch”. The sketch of the interior of the “Sankaido” which is one of the lava tunnels were also given.