9:20 AM - 9:35 AM
[SGL36-02] Geochemical characteristics of Miocene volcanic rocks in “Nagura Basalt formation”
Keywords:Basalt, chemical composition, Izu-Bonin arc
As a result, Nagura basalt is classified as low K, tholeiitic series like the current Izu-Bonin arc and Hinate andesite, Oshima basic intrusive, and it has a different chemical composition from the volcanic rocks of the Northeast Japan arc, and it also found that it has high FeO*/MgO ratio to the volcanic rocks of Izu Bonin arc and Hinate andesite, Oshima basic intrusive.
It is inferred that the tectonic environment at the time of the eruption of Nagura basalt was under the compressive crustal condition compared to the Quaternary volcanic rocks of the Izu- Bonin arc and Hinate andesite, Oshima basic intrusive.