Orbital-scale benthic foraminiferal oxygen isotope stratigraphy at the northern Bering Sea Slope Site U1343 (IODP Expedition 323) and its Pleistocene paleoceanographic significance

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• 作者：H. Asahi^a ; ^{asahiro@pusan.ac.kr" class="auth_mail" title="E-mail the corresponding author} ; S. Kender^b ; ^c ; M. Ikehara^d ; ^{ikheara@kochi-u.ac.jp" class="auth_mail" title="E-mail the corresponding author} ; T. Sakamoto^e ; ^f ; ^{tats@bio.mie-u.ac.jp" class="auth_mail" title="E-mail the corresponding author} ; K. Takahashi^g ; ^{kozotaka@hokusei.ac.jp" class="auth_mail" title="E-mail the corresponding author} ; A.C. Ravelo^h ; ^{acr@ucsc.edu" class="auth_mail" title="E-mail the corresponding author} ; C.A. Alvarez Zarikianⁱ ; ^{zarikian@iodp.tamu.edu" class="auth_mail" title="E-mail the corresponding author} ; B.K. Khim^j ; ^{bkkhim@pusan.ac.kr" class="auth_mail" title="E-mail the corresponding author} ; M.J. Leng^b ; ^k
• 关键词：Oxygen isotope stratigraphy ; Benthic foraminifera ; Pleistocene ; Sea-ice ; Bering Sea ; IODP
• 刊名：Deep Sea Research Part II: Topical Studies in Oceanography
• 出版年：2016
• 出版时间：March-April 2016
• 年：2016
• 卷：125-126
• 期：Complete
• 页码：66-83
• 全文大小：6045 K

文摘

A continuous composite oxygen isotope (δ¹⁸O) stratigraphy from benthic foraminifera in the Bering Sea was reconstructed in order to provide insight into understanding sea-ice evolution in response to Northern Hemisphere Glaciation. Oxygen isotope records from multiple species of benthic foraminifera at Integrated Ocean Drilling Program (IODP) Expedition 323 Site U1343 (54°33.4′N, 176°49.0′E, water depth 1950 m) yield a highly refined orbital-scale age model spanning the last 1.2 Ma, and a refined age model between 1.2 and 2.4 Ma. An inter-species calibration was used to define species offsets and to successfully obtain a continuous composite benthic δ¹⁸O record, correlated with the global composite benthic δ¹⁸O stack curve LR04 to construct an orbital-scale age model. The consistency of the benthic δ¹⁸O stratigraphy with biostratigraphy and magnetostratigraphy confirms the reliability of both methods for constraining age. The time difference between cyclic changes in sedimentary physical properties and glacial–interglacial cycles since 0.8 Ma is notable, and suggests that physical properties alone cannot be used to construct an orbital-scale age model. Amplitude changes in physical properties and a significant drop in the linear sedimentation rate during glacials after 0.9 Ma indicate that the glacial sea-ice edge extended beyond the Bering Sea Slope (Site U1343) at this time.