A marine controlled-source electromagnetic application using towed and seafloor-based receivers capable of mapping seafloor and embedded massive sulfides

• DOI: 10.1190/geo2023-0389.1
• Publication Date: 2024-02-19T12:55:20Z
• Authors: Keiichi Ishizu; Takafumi Kasaya; Tada-Nori Goto; Katsuaki Koike; Weerachai Siripun...; Hisanori Iwamoto; Yoshifumi Kawada; Jun-Ichiro Ishibashi
• Keywords: Seafloor Spreading; Seabed

Deep-sea massive sulfide deposits formed by hydrothermal fluid circulation are potential metal resources. They can exist not only as mound manifestations on the seafloor (seafloor sulfides) but also embedded anomalies buried beneath (embedded sulfides). The distribution of sulfides is largely unknown, despite their expected high economic value. Recent drilling surveys have revealed a complex model suggesting coexist sulfides. In coexisting case, geophysical methods required to distinguish and map for accurate resource estimation. Marine controlled-source electromagnetic (CSEM) useful mapping because they exhibit higher electrical conductivity compared with surrounding host rock. However, CSEM applications capable distinguishing lacking. We use towed electric dipole transmitter two types receivers: stationary ocean-bottom (OBE) short-offset receivers. This combination uses differences in sensitivity: receiver data sensitive sulfides, OBE Our synthetic example demonstrates that combined inversion recover resistivities positions more accurately than existing using individual applications. perform measured obtained from middle Okinawa Trough. models demonstrate location shape identified during sets.