Actively forming Kuroko-type volcanic-hosted massive sulfide (VHMS) mineralization at Iheya North, Okinawa Trough, Japan

• IODP Expedition 331 drilled five sites in the Iheya North hydrothermal field.
• We present new whole rock geochemical, minero-chemical and microstructural constraints.
• At site C0016 massive sphalerite-rich sulfides were intersected.
• Underlying volcanic rocks exhibit quartz-muscovite/illite and quartz-Mg-chlorite alteration.
• The Iheya North hydrothermal system represents a modern analogue for Kuroko-type deposits.