DOI: 10.1016/j.palaeo.2016.03.010
论文题名: Deep-sea benthic foraminiferal turnover across early Eocene hyperthermal events at Northeast Atlantic DSDP Site 550
作者: Arreguín-Rodríguez G.J. ; Alegret L.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2016
卷: 451 起始页码: 62
结束页码: 72
语种: 英语
英文关键词: Benthic foraminifera
; ETM2
; H2
; Hyperthermal events
英文摘要: Several extreme warming events, called hyperthermals, superimposed the warming trend of the early Paleogene. Deep-sea benthic foraminifera suffered major extinction during the most severe of those events, the Paleocene-Eocene Thermal Maximum, but their response to the following, less severe hyperthermals has been documented at very few locations. We evaluate and compare the benthic foraminiferal assemblages across ETM2 and H2 events at DSDP Site 550 in the NE Atlantic Ocean. The CIE and carbonate dissolution were more severe during ETM2 than during the H2 event.Early Eocene benthic foraminiferal assemblages were moderately diverse and strongly dominated by calcareous taxa, and they consisted of mixed infaunal and epifaunal morphogroups. They responded similarly to ETM2 and H2 events, showing a decrease in absolute abundance, an increase in the relative abundance of agglutinated taxa, indicative of more carbonate-corrosive waters, and a marked decrease in the percentage of Bolivinoides decoratus, suggesting a lower food supply during hyperthermals. However, some differences in their response were also noted. Oligotrophic taxa such as Nuttallides truempyi and Quadrimorphina profunda increased in relative abundance during early ETM2, whereas Globocassidulina subglobosa and Osangularia sp. 1, opportunistic species which may indicate pulsed food inputs, peaked during the H2 event. We conclude that both hyperthermal events represent a general disruption of an overall meso-oligotrophic environment, with less food reaching the seafloor combined with increased CaCO3 corrosivity of bottom waters. We did not find clear evidence for decreasing primary productivity during the hyperthermal events, and the apparent low food delivery to the seafloor may have been related to an increase in benthic foraminiferal metabolic rates due to the higher temperatures, with a more severe lack of food during ETM2 than during H2. The benthic foraminiferal response thus appears to be scaled to the magnitude of hyperthermals. © 2016 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68444
Appears in Collections: 过去全球变化的重建
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作者单位: Departamento de Ciencias de la Tierra, Universidad de Zaragoza, Pedro Cerbuna 12, Zaragoza, Spain; Instituto Universitario de Ciencias Ambientales, Universidad de Zaragoza, Zaragoza, Spain
Recommended Citation:
Arreguín-Rodríguez G.J.,Alegret L.. Deep-sea benthic foraminiferal turnover across early Eocene hyperthermal events at Northeast Atlantic DSDP Site 550[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2016-01-01,451