CGRG Bibliography of Canadian Geomorphology
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Author : Bowman, C.; Huntley, D.; and Bobrowsky, P.T.
Date : 1999
Title : Late Pleistocene to Holocene evolution of southern Vancouver Island based on freshwater lake sediment records.
Publication : 1999 Canadian Coastal Conference. Royal Roads University, Victoria, British Columbia, May 19-22, 1999.
Issue :
Page(s) :
Abstract
Sediment cores recovered from several freshwater lakes on southern Vancouver Island further expand the Holocene record recently provided by ODP Leg168S in Saanich Inlet, B.C. Six lakes: Elk/Beaver, Thetis, Pease, Durrance, Prospect and Spectacle were investigated during the last year with the aim to document local variations in sediment budget, vegetation history and timing of lake formation. Collectively, data from all the cores have been placed into the context of the ODP record to evaluate the regional paleoclimatic record, paleogeographic history and timing of deglaciation of the area surrounding Saanich Inlet for the period from the Late Pleistocene to the present. Lake elevations range from 42 m to 380 m asl. Recovered core lengths range from 85 to 298 cm. The 10 cm diameter cores were kept in cold storage at the Pacific Geoscience Centre, split and a routine series of analysis. Individual cores were first photographed and logged in detail documenting visible changes in color, structure, texture and other sedimentologic features including boundary contacts. Cores were subjected to resistivity measurements, loss on ignition determination, presence/absence documentation of macrofossils and charcoal analysis. The resistivity measurements are used as proxy indicators of relative grain size and pore water salinity. LOI analysis provided both organic and inorganic carbon values and are used as proxy records of vegatation history. All six lakes contain a record of the Mazama ash and thus provide a good correlative marker horizon of the 7600 calendric year event. 14C samples provide basal dates and relative estimates for deglaciation in the cores, as well as another time stratigraphic marker. The paleoenvironmental and paleogeographic records indicate a sensitive response in the local and regional environment to deglaciation, changing sea levels and landscape evolution over the last 13,000 years.
Bibliography of Canadian Geomorphology