气候变化领域集成服务门户(CCPortal): Sea-level and climate signatures recorded in orbitally-forced continental margin deposits over the last 1 Myr: New perspectives from the Bohai Sea

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DOI	10.1016/j.palaeo.2020.109736
	Sea-level and climate signatures recorded in orbitally-forced continental margin deposits over the last 1 Myr: New perspectives from the Bohai Sea
	Yao Z.; Shi X.; Liu Y.; Kandasamy S.; Qiao S.; Li X.; Bai Y.; Zhu A.
发表日期	2020
ISSN	0031-0182
卷号	550
英文摘要	Sediment accumulation in continental margins during the Quaternary Period was substantially influenced by both sea-level fluctuations and climate changes. However, the response of sediment accumulation to these changes on an orbital timescale, remains poorly understood, for two main reasons: the scarcity of sedimentary records with a high-resolution chronology, and the difficulty in distinguishing the role of sea-level from regional climate signals. Here we present the results of sediment color reflectance (c), grain size and total organic carbon (TOC) content of core BH08 (212.4 m in length, spanning the last ~1 Myr) recovered from the Bohai Sea, China. The chronology of core BH08 on the orbital timescale is constrained by both magnetostratigraphy and astronomical tuning. Sedimentary facies analysis suggests that the sedimentary sequence is dominated by the alternation of a deltaic system and floodplain deposition. Principal components analysis of the grain-size data reveals two principal components (PCs), including PC1, reflecting the 31–500 μm fraction, and PC2, reflecting the 18–66 μm fraction. Comparison of sample scores on PC1, PC2 and c with the alternation of sedimentary environments reveals that PC1 and c* reflect cycles of deltaic and floodplain deposition at ~100-kyr and ~40-kyr periodicities, while PC2 exhibits a ~20-kyr periodicity, in addition to the ~100-kyr and ~40-kyr cycles. We infer that PC1 and c* are mainly sea-level dependent, whereas PC2 is controlled by the combination of changes in monsoon climate and sea level. We suggest that Milankovitch-scale monsoon climate fluctuations controlled the sediments supply to the Bohai Sea during the last ~1 Myr, while the redistribution of sediments by marine processes (e.g., tidal currents) has partially obscured the monsoonal signal in the grain-size proxy (e.g., PC1) which instead is sensitive to sea-level change. Our results provide an example of the influence of climate and sea-level on sediment accumulation in a shallow continental margin setting influenced by monsoonal climate in an icehouse world. © 2020 Elsevier B.V.
英文关键词	Monsoon; Orbital forcing; Principal components analysis; Sedimentary facies; Transgression
语种	英语
scopus关键词	continental margin; facies analysis; floodplain; geoaccumulation; grain size; magnetostratigraphy; regional climate; sea level change; sedimentary sequence; total organic carbon; Bohai Sea; China; Pacific Ocean; Yellow Sea
来源期刊	Palaeogeography, Palaeoclimatology, Palaeoecology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/150492
作者单位	Key Laboratory of Marine Geology and Metallogeny, First Institute of Oceanography, MNR, Qingdao, 266061, China; Laboratory for Marine Geology, Laboratory for Marine Geology, Pilot National Laboratory for Marine Science and Technology, Qingdao, 266061, China; State Key Laboratory of Marine Environmental Science and Department of Geological Oceanography, Xiamen University, Xiamen, 361005, China
推荐引用方式 GB/T 7714	Yao Z.,Shi X.,Liu Y.,et al. Sea-level and climate signatures recorded in orbitally-forced continental margin deposits over the last 1 Myr: New perspectives from the Bohai Sea[J],2020,550.
APA	Yao Z..,Shi X..,Liu Y..,Kandasamy S..,Qiao S..,...&Zhu A..(2020).Sea-level and climate signatures recorded in orbitally-forced continental margin deposits over the last 1 Myr: New perspectives from the Bohai Sea.Palaeogeography, Palaeoclimatology, Palaeoecology,550.
MLA	Yao Z.,et al."Sea-level and climate signatures recorded in orbitally-forced continental margin deposits over the last 1 Myr: New perspectives from the Bohai Sea".Palaeogeography, Palaeoclimatology, Palaeoecology 550(2020).