新生代日本列島の火山活動とマントルダイナミクス

―この10年における進展―

抄録

 The Japanese Islands have experienced subduction of the old Pacific Plate and the young Philippine Sea Plate, as well as back-arc basin opening, such as at the Kurile basin, Japan Sea, Shikoku basin, and Okinawa trough. This paper summarizes progress in understanding mantle dynamics beneath Japan in the past ∼10 years in terms of igneous petrology and geochemistry, seismology, and numerical simulation. The discussion is separated into four regions: Hokkaido, northeast and central Japan, southwest Japan (Chugoku and Shikoku districts), and Kyushu, from northeast to the southwest. Now that a massive amount of volcanic eruption age data and high-resolution seismic analyses have been accumulated for every region, we can discuss mantle dynamics within mantle wedge and back arc mantle in more detail than in the 20^th century. Constraints related to water content, temperature, and melting process in the mantle from a natural sample are, however, still missing despite the importance of these factors when modeling mantle dynamics.