CGRG Bibliography of Canadian Geomorphology
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Author : Boyer-Villemaire, U.; St-Onge, G.; and Bernatchez, P.
Date : 2008.
Title : High resolution sedimentary records of climatic and land-use changes over the last few centuries in the Gulf of St. Lawrence.
Publication : 4th Canadian Conference on Geohazards: From Cause to Management. May 20-24, 2008. University Laval, Quebec City, Quebec.
Issue :
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Abstract
In the last few centuries, climatic and land-use changes have modified the sedimentary regime of coastal areas. In this paper, we will present a multiproxy approach performed on five sediment boxcores (max. water depth around 250 m) sampled on the North Shore of the Gulf of St. Lawrence in order to better understand the impacts of recent climatic or land-use changes in the coastal zone. The coring sites were carefully selected using multibeam and seismic surveys to avoid sampling locations showing signs of major disturbance. The chronology of the cores was established by 210Pb measurements and confirms that the sediments are recent (~AD 200 and 400 years). Quantification of the lithological variations in the cores was performed using 1) stratigraphic markers and various statistical-based granulometric measurements, 2) geochemical (C, N) and isotopic (d13C) tracers, 3) high resolution (100 µm) micro-fluorescence-X, and 4) physical and magnetic tracers (colour reflectance, magnetic measurements and CAT-Scan analysis). d13C of the organic matter, C/N ratios and organic carbon content reveal that the organic matter is of terrestrial and marine origin. In addition, a major shift in several parameters dated before AD 1900 years is observed. The origin of this shift, as well as other high frequency lithological variations will be investigated by spectral analysis (Fourier transform and wavelet analysis) and by comparison with an independent set of historical climatic and land-use change time series.
Bibliography of Canadian Geomorphology