抄録
This paper is a field-trip guide for one-day geological excursion of the southern part of the Shizuoka area, central Japan. The trip focuses on the field occurrences of the rocks of ultramafic-mafic igneous complex (Um-MIC) in the southern Setogawa Belt along the Circum-Izu Massif Serpentine Belt. The Setogawa Belt is an accretionary complex formed mainly during the Early Miocene, and is mainly composed of oceanic volcanics, deep-sea sediments (chert and micritic limestone), and clastic sedimentary rocks derived from the land area. The protrusion of the Um-MIC into the deep-sea muddy sediments began to occur before the subduction into the trench, and soon involved into the accretion-related fold-and-thrust system as sheet-like tectonic slices, giant blocks, ill-sorted breccias and smaller clasts within deep-sea mudstone beds. These occurrences may be comparable with those of the present-day submarine serpentinite volcanoes and their surroundings in the forearc region of the Izu-Bonin-Mariana Arc.
