Zinc and lead isotope variation in hydrothermal deposits from the Okinawa Trough

•Zinc isotope compositions of sphalerites from the OT are reported for the first time.•Mixing of Pb from different sources is the major cause of Pb isotope variation in OT.•Kinetic fractionation is the primary control on Zn isotope variation in the OT sulfides.•Zn isotopes may be used for ore exploration and discovery of new hydrothermal vents.