气候变化领域集成服务门户(CCPortal): Black Sea paleosalinity evolution since the last deglaciation reconstructed from alkenone-inferred Isochrysidales diversity

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DOI	10.1016/j.epsl.2021.116881
	Black Sea paleosalinity evolution since the last deglaciation reconstructed from alkenone-inferred Isochrysidales diversity
	Huang Y.; Zheng Y.; Heng P.; Giosan L.; Coolen M.J.L.
发表日期	2021
ISSN	0012821X
卷号	564
英文摘要	The Black Sea underwent dramatic changes in salinity from the last glacial maximum to Holocene as it evolved from a large inland lake to become a part of the global ocean due to post-glacial sea level rise. However, the detailed history of the re-connection of the Black Sea to the Mediterranean and the resulting Black Sea salinity variations have been heavily debated. We take advantage of our recent study on alkenones from phylogenetically classified haptophyte groups and their association with variable salinity levels in modern environments to reconstruct detailed salinity changes in the Black Sea over the past 16,000 years. We report the first discovery and documentation of alkenones from Group I Isochrysidales in relation to past salinity changes in the Unit III sediment. Our data indicate that the Black Sea surface salinity gradually increased from near fresh at ∼16 ka (∼1-2 psu) to oligohaline (∼ 5-6 psu) at ∼ 9.4 ka, the time of initial marine inflow, suggesting a negative regional hydrological balance. Although the IMI (initial marine inflow) occurred at 9.4 ka, the relatively low surface water salinity levels persisted to the beginning of sapropel formation at 7.6 ka, suggesting a strongly positive regional hydrological balance. Alkenone profiles also indicate a period of significantly reduced salinity between 3.5 and 1.6 ka, differing from the previous proposed peak salinity at 2.7 ka based on alkenone hydrogen isotope values. We demonstrate that the mismatch originates from the predominance of previously unidentified Group II Isochrysidales over E. huxleyi during this time interval, and when species-specific hydrogen isotopic fractionation of alkenones is taken into consideration, the isotope-inferred salinity between 3.5 and 1.6 ka is consistent with our proposal. Our new assessment of the Black Sea salinity evolution since the last glacial shows broad agreement with other regional records and provides a new basis for evaluating the impact of regional hydrological changes on Neolithic human migrations to Europe. © 2021 Elsevier B.V.
关键词	alkenones Black Sea group I Isochrysidales RIK37 salinity
英文关键词	Hydrogen; Isotopes; Sea level; Surface waters; Alkenones; Black sea; Group I; Hydrological balance; Isochrysidale; RIK37; Salinity; Salinity change; Salinity levels; Sea salinity; Glacial geology; alkenone; hydrogen isotope; hydrological change; isotopic fractionation; last deglaciation; Last Glacial Maximum; paleosalinity; reconstruction; salinity; sea level change; Black Sea; Isochrysidales
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/203141
作者单位	Department of Earth, Environmental and Planetary Science, Brown University, Providence, RI 02912, United States; Ecosystems Center, Marine Biological Laboratory, Woods HoleMA 02543, United States; Geology and Geophysics, Woods Hole Oceanography Institution, Woods HoleMA 02543, United States; Curtin University, School of Earth and Planetary Sciences, WA Organic and Isotope Geochemistry Centre (WA-OIGC), Bentley, WA 6102, Australia
推荐引用方式 GB/T 7714	Huang Y.,Zheng Y.,Heng P.,et al. Black Sea paleosalinity evolution since the last deglaciation reconstructed from alkenone-inferred Isochrysidales diversity[J],2021,564.
APA	Huang Y.,Zheng Y.,Heng P.,Giosan L.,&Coolen M.J.L..(2021).Black Sea paleosalinity evolution since the last deglaciation reconstructed from alkenone-inferred Isochrysidales diversity.Earth and Planetary Science Letters,564.
MLA	Huang Y.,et al."Black Sea paleosalinity evolution since the last deglaciation reconstructed from alkenone-inferred Isochrysidales diversity".Earth and Planetary Science Letters 564(2021).