Mineral major and trace elements data from Izu-Bonin-Mariana harzburgite and Tonga lherzolite

We studied harzburgite from the Izu–Bonin–Mariana forearc and lherzolite from the Tonga forearc to investigate mantle processes associated with subduction initiation. Major element compositions of minerals were analyzed using EMP, and trace elements were determined by LA-ICP-MS. We then conducted subsolidus corrections to clinopyroxene REE data and a series of open-system melting models to interpret the results, which are included in this file.