Geochemical mass balances are crucial for the understanding of how elements partition between the crust and mantle, especially where ocean crust is recycled from the seafloor back into the mantle during subduction. This research is a first-of-its-kind, proof-of-concept study that uses a novel, new, statistical approach to understand the extent to which the chemistry of rocks, that get subducted, comes back to earth's surface as magmas and gases in volcanic arcs like Japan and the Aleutians. The approach taken combines geoinformatics and data-mining of large compendiums of geochemical and isotopic data for seafloor volcanic rocks and sediments with calculations of potential, common, ocean crust, compositional end members. Data from volcanic arcs in the western and northern Pacific (Marianas through the Aleutians) will be analyzed, and quality-controlled compendiums of data will be compiled for analysis. Broader impacts of the work include support of a PI from groups under-represented in the sciences and undergraduate student training in geoinformatics. The work is relevant to the NSF-funded MARGINS and Ocean Drilling Program missions and science plans. Resulting data will be publicly available through the NSF-funded PetDB data portal and data archive.