气候变化领域集成服务门户(CCPortal): Simulation of oxygen isotopes and circulation in a late Carboniferous epicontinental sea with implications for proxy records

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DOI	10.1016/j.epsl.2021.116770
	Simulation of oxygen isotopes and circulation in a late Carboniferous epicontinental sea with implications for proxy records
	Macarewich S.I.; Poulsen C.J.; Montañez I.P.
发表日期	2021
ISSN	0012821X
卷号	559
英文摘要	Reconstructions of ancient ocean chemistry are largely based on geochemical proxies obtained from epicontinental seas. Mounting evidence suggests that these shallow inland seas were chemically distinct from the nearby open ocean, decoupling epicontinental records from broader ocean conditions. Here we use the isotope-enabled Community Earth System Model to evaluate the extent to which the oxygen isotopic composition of the late Carboniferous epicontinental sea, the North American Midcontinent Sea (NAMS), reflects the chemistry of its open-ocean sources and connect epicontinental isotope variability in the sea to large-scale ocean-atmosphere processes. Model results support estuarine-like circulation patterns demonstrated by past empirical studies and suggest that orographic runoff produced decreases in surface seawater δ18O (δ18Ow) of up to ∼3‰ between the NAMS and the bordering ocean. Simulated sea surface temperatures are relatively constant across the sea and broadly reproduced from proxy-based δ18O paleotemperatures for which model-based values of epicontinental δ18Ow are used, indicating that offshore-onshore variability in surface proxy δ18O is primarily influenced by seawater freshening. Simulated bottom water temperatures in the NAMS are also reproduced from biogenic calcite δ18O using model-based values of epicontinental δ18Ow, suggesting that benthic marine fossil δ18O is also influenced by seawater freshening and coastal upwelling. In addition, glacial-interglacial variations in nearshore seawater freshening counteract the effects of temperature on marine biogenic δ18O values, suggesting that salinity effects should be considered in δ18O-based estimates of glacioeustatic sea level change from nearshore regions of the NAMS. Our results emphasize the importance of constraining epicontinental dynamics for interpretations of marine biogenic δ18O as proxies of paleotemperature, salinity, and glacioeustasy. © 2021 Elsevier B.V.
关键词	Carboniferous epicontinental sea late Paleozoic ice age seawater circulation seawater oxygen isotopes
英文关键词	Atmospheric chemistry; Calcite; Earth atmosphere; Isotopes; Offshore oil well production; Oxygen; Sea level; Surface waters; Temperature; Circulation patterns; Coastal upwelling; Earth system model; Effects of temperature; Geochemical proxies; Nearshore regions; Oxygen isotopic composition; Sea surface temperature (SST); Seawater effects; Carboniferous; computer simulation; glacioeustacy; inland sea; numerical model; oceanic circulation; oxygen isotope; paleoceanography; paleoclimate; paleosalinity; paleotemperature; Paleozoic; proxy climate record; reconstruction; seawater; North America
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/203206
作者单位	Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, 1100 N. University Avenue, Ann Arbor, MI 48109, United States; Department of Earth and Planetary Sciences, University of California, Davis, One Shields Avenue, Davis, CA 95616, United States
推荐引用方式 GB/T 7714	Macarewich S.I.,Poulsen C.J.,Montañez I.P.. Simulation of oxygen isotopes and circulation in a late Carboniferous epicontinental sea with implications for proxy records[J],2021,559.
APA	Macarewich S.I.,Poulsen C.J.,&Montañez I.P..(2021).Simulation of oxygen isotopes and circulation in a late Carboniferous epicontinental sea with implications for proxy records.Earth and Planetary Science Letters,559.
MLA	Macarewich S.I.,et al."Simulation of oxygen isotopes and circulation in a late Carboniferous epicontinental sea with implications for proxy records".Earth and Planetary Science Letters 559(2021).