Imaging hydrothermal mineral deposits area by reflection seismic processing using Vertical Cable Seismic and Ocean Based Sound Source

摘要

For the estimation of the hydrothermal mineral deposits reserves, geophysical exploration is indispensable, and the practical geophysical survey was conducted in 2013 at the Izena cauldron in the Okinawa trough, known distribution area of the hydrothermal deposits. Shallow seismic data were successfully acquired by the Vertical Cable Seismic method with the Ocean Based Sound Source (VCS-OBSS system). The OBSS system can generate high frequency waves of 1kHz Ricker wavelet, and high resolution data were acquired at this complex hydrothermal area. The data were processed by the three-dimensional Pre-Stack Depth Migration (3D-PSDM) method, and the output volume size was 160m × 220m × 400m. As a result of the interpretation, several continuous reflectors were detected, considering to be indicating the buried sulfide ore mound and the stockwork zone. This study concludes that the VCS-OBSS system is one of the effective geophysical methods for the exploration of the ocean bottom hydrothermal mineral deposits.