6:15 PM - 7:30 PM
[HQR23-P08] Stratigraphic correlation of multiple coring sites in Lake Suigetsu, Fukui prefecture, central Japan
Keywords:Lake Suigetsu, Event stratigraphy, Varve, Turbidite, Stratigraphic correlation
The SG14 core was obtained from 4 separate boreholes (E, F, G, H) to ensure overlapping with each other. The combined core sections were nearly 100 m long, going ca. 30 % deeper than the SG06 core, and were almost wholly continuous except for two cm-scale gaps. Almost all of event layers of the SG14 core, such as tephras, turbidites, could be correlated with that of the SG06 core. On the basis of this correlation, average sedimentation rate of the SG14 core was equivalent to that of SG06; however, the coarse layers of turbidites were different in thickness between each core. These observations support the idea that most of event layers spread out over wide areas of the lake bottom. Furthermore the variation in thickness between the cores provides key geographical origin and pathways of these event layers. The upper parts of the SG14 core (0 to 44 m in composite depth) are mainly dominated by varved sediments. Whilst the middle (44 to 65 m in composite depth) and lower parts (65 to bottom in composite depth) of the SG14 core lack laminated sediment; the middle parts primarily consist of massive sediment, and the lower parts are composed of black-brown peat and cyclically intercalated with more inorganic grey sediments. These stratigraphic transitions probably indicate hydrological change of the lake catchment.
Bronk Ramsey et al., 2012, Science, 338, 370-374.
Marshall et al., 2012, Quaternary Geochronology, 13,70-80.
Nakagawa et al., 2012, Quaternary Science Reviews, 36, 164-176.
Okada, 2004, Geomorphology of Kinki, Chugoku and Shikoku (in Japanese), University of Tokyo Press, p179-189.
Reimer et al., 2013, Radiocarbon, 55, 1869-1887.
Schlolaut et al., 2012, Quaternary Geochronology, 13, 52-69.
Schlolaut et al., 2014, Quaternary Science Reviews, 83, 157-170.
Staff et al., 2011, Radiocarbon, 53, 511-528.