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TitleDiatom-based Holocene paleoenvironmental records from continental sites on northeastern Ellesmere Island, high Arctic, Canada.
 
AuthorSmith, I RORCID logo
SourceJournal of Paleolimnology vol. 27, no. 1, 2002 p. 9-28
Image
Year2002
Alt SeriesGeological Survey of Canada, Contribution Series 2000189
Alt SeriesPolar Continental Shelf Project, Contribution 02800
Documentserial
Lang.English
Mediapaper
ProvinceNunavut
NTS120C
AreaEllesmere Island
Lat/Long WENS -72.0000 -64.0000 82.0000 81.0000
Subjectsenvironmental geology; marine geology; paleontology; surficial geology/geomorphology; arctic geology; climate, arctic; diatoms; paleoenvironment; climate; marine environments; Holocene; paleoclimatology
Illustrationslocation maps; aerial photographs; geological sketch maps; tables; formulae; graphs
ProgramNSERC Natural Sciences and Engineering Research Council of Canada
ProgramIndian and Northern Affairs Canada, Northern Studies Training Grant
ProgramUniversity of Alberta, Canadian Circumpolar Institute, Circumpolar/Boreal Alberta Research (C/BAR) Grant
ProgramUniversity of Alberta, Harington Paleoenvironmental Scholarship
ProgramUniversity of Alberta, Killam Memorial Scholarship
AbstractStratigraphic changes in diatom assemblages from four small lakes on northeastern Ellesmere Island, high Arctic, Canada, provide a proxy lake-ice cover and paleoenvironmental record. Low absolute diatom abundances and a benthic Fragilaria (sensu lata) dominated assemblage during the postglacial (< 7.6 ka B.P.) to mid-Holocene record the moderating effects of locally retreating glaciers. Around 5.5 ka B.P. diatom concentrations begin to rise, reaching their highest levels (109 valves per g dry sediment) between 4.2 and 3 ka B.P., interpreted to be the warmest period in this region. Topoclimatic differences between lakes on Hazen Plateau and those lower in Lake Hazen Basin account for the initial decline in diatom abundances in the upper lakes after 3 ka B.P. This change is thought to reflect a lowering of the regional snowline, accordant with widely recognized Neoglacial advances on Ellesmere Island and Greenland. Lakes in lower Lake Hazen Basin maintained extensive summer ice free conditions until ~ 1.9 ka B.P., after which diatom abundances declined, suggesting prolonged summer lake-ice cover through the remainder of the recovered Holocene record. Differences between the records presented here and those from coastal areas of the Canadian high Arctic highlight the unique topoclimatic characteristics and continentality of the Lake Hazen region, and possible effects that local marine environments may have had on coastal records. Such differences serve to demonstrate the inherent geographic variability of paleoenvironmental records from the high Arctic.
GEOSCAN ID211782

 
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