Kuroko-type Deposits of the Misaka-Koma Mountains in the Izu collision zone, central Japan: Their Occurrence and Geological Implications

Abstract

We identified six Kuroko-type deposits in the Izu collision zone, central Japan, which formed as seafloor massive sulfides (SMS) in the Paleo-Izu Arc before its collision with the Honshū Arc during the middle Miocene. These deposits are found in the same stratigraphic horizon (~15 Ma) in the Nishiyatsushiro and Koma groups, between the basaltic volcanic sequence of the Furusekigawa Formation (or its equivalent) and the hanging-wall mudstone of the Tokiwa Formation of the Nishiyatsushiro Group (or the equivalent sedimentary unit in the Koma Group).