DOI: 10.5194/cp-13-17-2017
Scopus记录号: 2-s2.0-85009260450
论文题名: Hydrological variations of the intermediate water masses of the western Mediterranean Sea during the past 20 ka inferred from neodymium isotopic composition in foraminifera and cold-water corals
作者: Dubois-Dauphin Q. ; Montagna P. ; Siani G. ; Douville E. ; Wienberg C. ; Hebbeln D. ; Liu Z. ; Kallel N. ; Dapoigny A. ; Revel M. ; Pons-Branchu E. ; Taviani M. ; Colin C.
刊名: Climate of the Past
ISSN: 18149324
出版年: 2017
卷: 13, 期: 1 起始页码: 17
结束页码: 37
语种: 英语
Scopus关键词: benthic foraminifera
; carbon isotope
; continental margin
; deep water
; hydrological change
; intermediate water
; isotopic composition
; neodymium isotope
; planktonic foraminifera
; sediment core
; stratification
; water depth
; water mass
; Alboran Sea
; Balearic Sea
; Levantine Sea
; Mediterranean Sea
; Sardinia Channel
; Anthozoa
; Cibicidoides pachyderma
; Foraminifera
; Globigerina bulloides
; Lophelia pertusa
; Madrepora oculata
; Scleractinia
英文摘要: We present the neodymium isotopic composition (ϵNd) of mixed planktonic foraminifera species from a sediment core collected at 622m water depth in the Balearic Sea, as well as ϵNd of scleractinian cold-water corals (CWC; Madrepora oculata, Lophelia pertusa) retrieved between 280 and 442m water depth in the Alboran Sea and at 414m depth in the southern Sardinian continental margin. The aim is to constrain hydrological variations at intermediate depths in the western Mediterranean Sea during the last 20 kyr. Planktonic (Globigerina bulloides) and benthic (Cibicidoides pachyderma) foraminifera from the Balearic Sea were also analyzed for stable oxygen (δ18O) and carbon (δ13C) isotopes. The foraminiferal and coral ϵNd values from the Balearic and Alboran seas are comparable over the last ∼13 kyr, with mean values of-8.94±0.26 (1σ; n D24) and-8.91±0.18 (1σ; n D25), respectively. Before 13 ka BP, the foraminiferal ϵNd values are slightly lower (-9.28±0.15) and tend to reflect higher mixing between intermediate and deep waters, which are characterized by more unradiogenic ϵNd values. The slight ϵNd increase after 13 ka BP is associated with a decoupling in the benthic foraminiferal 13C composition between intermediate and deeper depths, which started at ∼16 ka BP. This suggests an earlier stratification of the water masses and a subsequent reduced contribution of unradiogenic ϵNd from deep waters. The CWC from the Sardinia Channel show a much larger scatter of ϵNd values, from-8.66±0.30 to-5.99±0.50, and a lower average (-7.31±0.73; n D19) compared to the CWC and foraminifera from the Alboran and Balearic seas, indicative of intermediate waters sourced from the Levantine basin. At the time of sapropel S1 deposition (10.2 to 6.4 ka), the ϵNd values of the Sardinian CWC become more unradiogenic (-8.38±0.47; n D3 at ∼8.7 ka BP), suggesting a significant contribution of intermediate waters originated from the western basin. We propose that western Mediterranean intermediate waters replaced the Levantine Intermediate Water (LIW), and thus there was a strong reduction of the LIW during the mid-sapropel (∼8.7 ka BP). This observation supports a notable change of Mediterranean circulation pattern centered on sapropel S1 that needs further investigation to be confirmed. © 2017 The Author(s). 资助项目: Consiglio Nazionale delle Ricerche
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/48948
Appears in Collections: 气候变化与战略
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Recommended Citation:
Dubois-Dauphin Q.,Montagna P.,Siani G.,et al. Hydrological variations of the intermediate water masses of the western Mediterranean Sea during the past 20 ka inferred from neodymium isotopic composition in foraminifera and cold-water corals[J]. Climate of the Past,2017-01-01,13(1)