Abstract
Two ‘anomalous’ deposits with well-preserved sedimentary structures were discovered in a drowned valley and in relict barrier sand body deposits in the Furuya Mud and Kyomatsubara Sand of the Upper Pleistocene incised valley fills. The sedimentary features of both deposits are interpreted as ‘earthquake-induced tsunami deposits’, which were deposited in incised valley fills. The tsunami deposit in the drowned valley (Furuya Mud) is 150 cm thick and shows a contorted structured bed in the lower part and cross-laminated sand in the upper part. The tsunami deposit in barrier sand body (Kyomatsubara Sand) is 270 cm thick and shows structureless sand with mud clasts in the lower part, cross-laminated sand with mud-drapes in the middle part and mud with small wave-ripples in the upper part. Taken together, these sedimentary features suggest a model for the composite succession, which is comprised of three units: a lower earthquake-shock-influenced (anomalous) convoluted part, a middle part dominated by tsunami-generated tractional currents, and an upper suspended-sediment part. The lower part is interpreted as earthquake event deposits (seismites) and the middle and upper parts as tsunami current deposits (tsunamiites).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.