DOI: 10.1016/j.palaeo.2015.10.026
论文题名: High resolution dinoflagellate cyst record of environmental change in Effingham Inlet (British Columbia, Canada) over the last millennium
作者: Bringué M. ; Pospelova V. ; Calvert S.E. ; Enkin R.J. ; Lacourse T. ; Ivanochko T.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2016
卷: 441 起始页码: 787
结束页码: 810
语种: 英语
英文关键词: Laminated sediments
; Little Ice Age
; Medieval Climate Anomaly
; Paleoseismicity
; Primary productivity reconstructions
; Warming in the second half of the 20th century
英文摘要: We present a high resolution sedimentary record of dinoflagellate cysts spanning the last 900years recovered from Effingham Inlet, a glacial fjord on the west coast of Vancouver Island, Canada. The combination of seasonal coastal upwelling supporting high levels of marine primary productivity in surface waters, together with restricted bottom water circulation in the silled fjord, fosters the preservation of laminated sediments in the inner basin of Effingham Inlet. Geochemical data are used to assess the sedimentary facies of the core, which is composed primarily of laminated units (50.2%) occasionally interrupted by "seismites" (39.5%) and homogenous units (10.2%). The chronology of the 2m-long core is based on varve counting and fifteen 14C dates, and is anchored by a seismite previously dated at AD 1946.The dinoflagellate cyst assemblages are diverse (total of 47 taxa), abundant (average concentrations of 102,900cystg-1 of dry sediment), and characterized by a proportionally equal contribution of autotrophic and heterotrophic cyst taxa in most samples. Overall, cyst assemblages are characterized by Operculodinium centrocarpum (36.2%) accompanied by Brigantedinium spp. (18.0%) and Dubridinium spp. (6.6%). Multivariate analyses are used to extract the dominant patterns of variability in autotrophic and heterotrophic dinoflagellate cyst assemblages separately, and help in identifying the temperature and primary productivity gradients encoded in the cyst sedimentary record in this particular estuary.Specific intervals identified in the dinoflagellate cyst record are interpreted to represent the local expression of the "Medieval Climate Anomaly" (from the base of the record, AD 1090 to 1230), the "Little Ice Age" (AD 1230 to late 19th century) and warming in the second half of the 20th century. The timing of these intervals are consistent with the regional paleoclimate and help constrain past climatic and oceanographic variability on the west coast of Vancouver Island. The origin of homogenous units in the sedimentary record of Effingham Inlet and paleoseismicity in the region are also discussed. © 2015 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68651
Appears in Collections: 过去全球变化的重建
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作者单位: School of Earth and Ocean Sciences, University of VictoriaBC, Canada; Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC, Canada; Geological Survey of Canada-Pacific, Sidney, BC, Canada; Department of Biology, University of VictoriaBC, Canada
Recommended Citation:
Bringué M.,Pospelova V.,Calvert S.E.,et al. High resolution dinoflagellate cyst record of environmental change in Effingham Inlet (British Columbia, Canada) over the last millennium[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2016-01-01,441