气候变化领域集成服务门户(CCPortal): Influence of increasing carbonate saturation in Atlantic bottom water during the late Miocene

CCPortal

DOI	10.1016/j.palaeo.2019.01.006
	Influence of increasing carbonate saturation in Atlantic bottom water during the late Miocene
	Keating-Bitonti C.R.; Peters S.E.
发表日期	2019
ISSN	0031-0182
起始页码	134
结束页码	142
卷号	518
英文摘要	The late Miocene witnessed the tectonic uplift of the Isthmus of Panama, the onset of modern-like thermohaline circulation, changes in global patterns of deep-sea sedimentation, and a negative shift of ~1‰ in the carbon isotopic composition (δ 13 C) of marine carbonate sediments. Although previous work has attributed the late Miocene carbon isotopic shift (LMCS) to biological and environmental factors, the reasons for this apparent shift in the global carbon cycle remain incompletely understood. Here we combine both core-based sedimentological and isotopic data from three Walvis Ridge sites in the southeastern Atlantic Ocean with macrostratigraphic data from the entire Atlantic basin to show that the LMCS marks the establishment of modern, glacial/interglacial seawater carbonate saturation levels in the Atlantic. Between 10 and 7 million years ago (Ma) the Atlantic Ocean shows a trend of increasing seafloor area preserving deep-sea carbonate sediments. Neogene carbonate sedimentation in the Atlantic Ocean peaked at 7 Ma, coinciding with a δ 13 C shift of approximately −0.8‰ in Walvis Ridge benthic foraminifera, similar to the magnitude of LMCS. Northern-sourced waters in the late Miocene likely shifted seawater carbonate chemistry throughout the Atlantic basin by introducing bottom waters with higher carbonate ion concentrations. LMCS reflects the introduction of a carbonate ion effect on North Atlantic Deep Water (NADW) by increasing Northern Hemisphere glacial carbonate weathering. A carbonate ion flux to the Labrador Seawater contribution of NADW raises the possibility of a carbonate burial-mediated feedback with the global climate system that led to additional cooling during the Miocene-Pliocene transition. © 2019
英文关键词	CaCO 3 preservation; Carbon cycling; Macrostratigraphy; Stable carbon isotopes; Thermohaline circulation; Walvis Ridge
语种	英语
scopus关键词	Antarctic Bottom Water; benthic foraminifera; bottom water; calcium carbonate; carbon cycle; carbon isotope; carbonate sediment; cooling; deep-sea organism; glacial-interglacial cycle; global climate; isotopic composition; Miocene; Northern Hemisphere; Pliocene; saturation; seafloor; seawater; sedimentation; stable isotope; thermohaline circulation; uplift; Atlantic Ocean; Atlantic Ocean (North); Atlantic Ocean (Southeast); Isthmus of Panama; Labrador Sea; Panama [Central America]; Walvis Ridge; Foraminifera
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/151068
作者单位	Department of Geoscience, University of Wisconsin – Madison, Madison, WI 53706, United States
推荐引用方式 GB/T 7714	Keating-Bitonti C.R.,Peters S.E.. Influence of increasing carbonate saturation in Atlantic bottom water during the late Miocene[J],2019,518.
APA	Keating-Bitonti C.R.,&Peters S.E..(2019).Influence of increasing carbonate saturation in Atlantic bottom water during the late Miocene.Palaeogeography, Palaeoclimatology, Palaeoecology,518.
MLA	Keating-Bitonti C.R.,et al."Influence of increasing carbonate saturation in Atlantic bottom water during the late Miocene".Palaeogeography, Palaeoclimatology, Palaeoecology 518(2019).