HR: 16:30h
AN: T44A-03    [Abstracts]
TI: Earthquake-induced submarine sliding on the trench-slope basin within the Late Pliocene to Pleistocene Chikura Group, Central Japan
AU: * Yamamoto, Y
EM: yuzuru@ni.aist.go.jp
AF: Geological Survey of Japan, AIST, Tsukuba Central 7, 1-1-1 Higashi, Tsukuba, 305-8567, Japan
AU: Suzuki, K
EM: tade-suzuki@aist.go.jp
AF: Geological Survey of Japan, AIST, Tsukuba Central 7, 1-1-1 Higashi, Tsukuba, 305-8567, Japan
AB: Fossil example of large-scale sediment mass wasting occurred on the trench-slope-basin was identified. A large-scale chaotic sedimentary body within Late Pliocene to Pleistocene trench-slope cover sediments of the Chikura Group, Central Japan, can be traced E�|W over a distance of 5 km. A recently excavated road cutting has exposed a cross-section through the entire chaotic sedimentary body, including its upper and lower contacts with coherent sediments. Evidence of sand intrusions and block rotation within the body indicates that the chaotic nature of the sediments arose from earthquake-induced liquefaction and subsequent submarine sliding (liquefied sediment flow). It is possible that the formation of such a large-scale submarine slide body generated a large tsunami. We will report a detailed description of the occurrence and structural characteristics of this recently exposed outcrop of chaotically mixed sediments.
DE: 3040 Plate tectonics (8150, 8155, 8157, 8158)
DE: 8021 Melanges
DE: 8025 Mesoscopic fabrics
DE: 8030 Microstructures
DE: 8175 Tectonics and landscape evolution
SC: Tectonophysics [T]
MN: 2007 Fall Meeting