Updated Izu sample geochemical analysis compilation

This dataset is an updated version of Gill, 2019 (https://doi.org/10.1594/IEDA/111181). It contains published and previously unpublished XRF and ICP-MS analyses from the University California Santa Cruz (UCSC) for rock samples dredged from, and mostly behind, the Izu (Japan) volcanic front from 30° to 31°N, or from and behind Torishima to Aogashima. Most were dredged using the R/V Moana Wave in 1995. Additional data for samples from these dredges are provided in publications by Ishizuka, Machida, and Haragichi. A new distinction is made between Rift- and Rear Arc Seamount Chain-types. It relies on trace element and isotope geochemistry and supersedes the distinction between Active Rifts, Back Arc Knolls, and Western Seamounts. Samples are being archived at The University of Rhode Island- Graduate School of Oceanography. They will be available to anyone by application to URI (Kelley Group http://www.gso.uri.edu/kelley/Welcome.html).