Cyclo-stratigraphy of the Pliocene-Miocene interval in the Japan Sea sediments (Exp. 346 Site U1425 and U1430)

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http://abstractsearch.agu.org/meetings/2016/FM/PP41B-2246.html
Author(s): Kurokawa, Shunsuke; Tada, Ryuji; Irino, Tomohisa; Seki, Arisa; Itaki, Takuya; Kamikuri, Shin-Ichi; Matsuzaki, Kenji Marc Raymond; Murray, Richard W.; Alvarez Zarikian, Carlos A.
Integrated Ocean Drilling Program, Expedition 346 Scientists
Author Affiliation(s): Primary:
University of Tokyo, Bunkyo-ku, Japan
Other:
Hokkaido University, Japan
Geological Survey of Japan, Japan
Ibaraki University, Japan
Boston University, United States
Texas A&M University, United States
Volume Title: AGU 2016 fall meeting
Source: American Geophysical Union Fall Meeting, Vol.2016; American Geophysical Union 2016 fall meeting, San Francisco, CA, Dec. 12-16, 2016. Publisher: American Geophysical Union, Washington, DC, United States
Note: In English
Summary: Since the Middle Miocene, the climate of the Earth recorded a stepwise cooling, characterized by the east Antarctic ice sheet expansion and the onset of the northern hemisphere glaciation. Paleoceanographic changes have been reconstructed using deep-sea sediments from Atlantic and southern Pacific at high-resolution. The results revealed a close linkage between changes in ice volume and changes in orbital parameters. However, an orbitally-tuned continuous age model for the Middle Miocene to Pliocene has not been yet established in the North Pacific. Since the Middle Miocene the Japan Sea has been a semi-closed marginal sea. Because the sea has been connected with the north Pacific by relatively shallow sills, its paleoceanographic condition has been sensitive to glacio-eustatic sea-level changes. Deep-sea cores collected previously from the Japan Sea showed that changes in core lithology could be associated to variation in sea-level. If correct, it is possible to construct a high-resolution and high-precision age model based on orbital-tuning of lithological variations observed in hemipelagic sediments of this sea. In this study, we utilize Integrated Ocean Drilling Program cores recovered from Sites U1425 and U1430 during Exp. 346. We constructed continuous sedimentary records at these two sites by revising the shipboard splices. Using the revised splices and available biostratigraphic data, we constructed a biostratigraphically-based age models for both sites. Based on these age models, we converted GRA and NGR data from depth series to time series, extracted ca. 400- and 41-kyr cyclicities, and tuned them to 400-kyr eccentricity cycle and 41-kyr obliquity cycle, respectively, to construct orbitally-tuned age models. We also conducted inter-site correlation for the overlapping interval spanning from 7 to 9 Ma, to confirm the suitability of our orbitally-tuned age models. In the presentation, we will discuss the timings of paleoceanographic events observed in the Japan Sea and their relation with changes in ice volume, orbital parameters, and other global-scale events.
Year of Publication: 2016
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Cenozoic; Cyclostratigraphy; Expedition 346; IODP Site U1425; IODP Site U1430; Integrated Ocean Drilling Program; Japan Sea; Marine sediments; Miocene; Neogene; North Pacific; Northwest Pacific; Pacific Ocean; Pliocene; Sediments; Tertiary; Ulleung Basin; West Pacific; Yamato Rise
Coordinates: N392926 N392927 E1342634 E1342632
Record ID: 2017062403
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