气候变化领域集成服务门户(CCPortal): Intensified oceanic circulation during Early Carboniferous cooling events: Evidence from carbon and nitrogen isotopes

CCPortal

DOI	10.1016/j.palaeo.2018.10.021
	Intensified oceanic circulation during Early Carboniferous cooling events: Evidence from carbon and nitrogen isotopes
	Liu J.; Algeo T.J.; Qie W.; Saltzman M.R.
发表日期	2019
ISSN	0031-0182
卷号	531
英文摘要	The Early Carboniferous was a climatic transition interval from a mid-Paleozoic greenhouse world into the Late Paleozoic Ice Age. It was marked by a long-term cooling trend that was punctuated by short glaciations in the Tournaisian and Visean (early to mid-Early Carboniferous). Here, we generated organic carbon and nitrogen isotope profiles for two widely separated Lower Carboniferous sections (Arrow Canyon Range, Nevada, and Namur-Dinant Basin, Belgium) in order to assess the global nature and timing of changes in the carbon‑nitrogen cycles linked to oceanic productivity and redox conditions during this climatic transition interval. The carbon and nitrogen isotope profiles of both study sections record major perturbations during the mid-Tournaisian and Visean. A mid-Tournaisian event (TICE) is marked by increases in δ13Ccarb, δ13Corg, and δ15Nbulk at Arrow Canyon (from +0.6 to +7.0‰, −25.2 to −23.7‰, and –0.6 to +8.9‰, respectively) and Namur-Dinant (from −0.3 to +4.7‰, −27.9‰ to −22.2‰, and –5.7 to +5.2‰, respectively). An early Visean event (VICE; named herein) is marked by increases in δ13Ccarb, δ13Corg, and δ15Nbulk at Arrow Canyon (from −0.6 to +3.1‰, −28.4 to −23.6‰, and +1.4 to +9.4‰, respectively) and Namur-Dinant (from +2.1 to +4.3‰, −26.7 to −25.0‰, and –1.4 to +3.3‰, respectively). The positive excursions in all three isotopic records during these events are consistent with increased fractional burial of organic carbon and enhanced denitrification, implying intensification of marine productivity and expansion of hypoxia in the global ocean. Given that each event coincided with lowering of sea-surface temperatures and increased glaciation (as documented from published conodont δ18O and sea-level records), we hypothesize that global cooling led to intensified oceanic circulation and upwelling on continental margins, triggering increased marine productivity and attendant redox changes within the affected upwelling zones. Our results provide new insights into changes in Early Carboniferous oceanic conditions in response to the initial stages of cooling leading into the Late Paleozoic Ice Age. © 2018 Elsevier B.V.
英文关键词	Arrow Canyon; Euramerica; Mississippian; Namur-Dinant; Tournaisian; Visean
语种	英语
scopus关键词	carbon isotope; Carboniferous; cooling; Mississippian; nitrogen isotope; oceanic circulation; redox conditions; Tournaisian; upwelling; Visean; Arrow Canyon Range; Belgium; Dinant Basin; Namur [Belgium]; Nevada; Nevada; United States
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/150873
作者单位	State Key Laboratory of Biogeology and Environmental Geology and School of Earth Sciences, China University of Geosciences, Wuhan, 430074, China; Department of Geology, University of Cincinnati, Cincinnati, OH 45221-0013, United States; State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, 430074, China; CAS Key Laboratory of Economic Stratigraphy and Palaeogeography, Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment, Chinese Academy of Sciences, Nanjing, 210008, China; School of Earth Sciences, Ohio State University, Columbus, OH 43210, United States
推荐引用方式 GB/T 7714	Liu J.,Algeo T.J.,Qie W.,et al. Intensified oceanic circulation during Early Carboniferous cooling events: Evidence from carbon and nitrogen isotopes[J],2019,531.
APA	Liu J.,Algeo T.J.,Qie W.,&Saltzman M.R..(2019).Intensified oceanic circulation during Early Carboniferous cooling events: Evidence from carbon and nitrogen isotopes.Palaeogeography, Palaeoclimatology, Palaeoecology,531.
MLA	Liu J.,et al."Intensified oceanic circulation during Early Carboniferous cooling events: Evidence from carbon and nitrogen isotopes".Palaeogeography, Palaeoclimatology, Palaeoecology 531(2019).