Correlation of Quaternary Volcano Clusters With Partial Melting of Mantle Wedge, Northeast Japan: A Numerical Model Study

The Quaternary volcano clusters in Northeast Japan and the no-volcano zones between them imply extensive and scarce melting, respectively, in the mantle wedge, but no quantitative study on the heterogeneous melting has been conducted. Here, we constructed two-dimensional numerical models by considering along-arc temperature variations in the mantle wedge expressed as high- (hot fingers) and low-temperature anomalies (deterred corner flow) with the slab dehydration, porous flow of aqueous fluid, and partial melting of the mantle wedge. The results show that the high- and low-temperature anomalies in the mantle wedge result in extensive and negligible melting beneath the volcano clusters and no-volcano zones, respectively, consistent with geochemical and geophysical estimations. Contrary to the near-complete slab dehydration beneath the volcano clusters, the partially dehydrated subducting slab beneath the no-volcano zones transports the remaining water into the mantle transition zone, which has implications for intraplate volcanoes in Northeast Asia.