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

Abstract

AbstractThe 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.