CGRG Bibliography of Canadian Geomorphology
Search Results
Author : Courtney Mustaphi, C.; and Gajewski, K.
Date : 2007.
Title : Annually laminated sediment from a lake Devon Island; implications for paleoclimatic inferences.
Publication : CANQUA Ottawa 2007. Canadian Quaternary Association Conference, June 4-8, 2007. Carleton University, Ottawa, Ontario, Canada.
Issue :
Page(s) :
Abstract
A small coastal lake on northern Devon Island (DV09; 75 ° 34.34'N, 89 ° 18.55'W), Nunavut, Canada was cored in the deepest part of the basin (16m) as well as around the periphery. The deep cores contain alternating dark and light laminae couplets that have been shown to be annually laminated in the uppermost sediment by the correspondence between 210Pb dating and the varve count (Gajewski, et al, 1997 Journal of Paleolimnology). The purpose of this study is to build a stratigraphic sequence by cross-dating multiple cores from the lake and use the varve chronology to infer past climate conditions of the watershed region. Lamination widths down to a depth of 5.87m on a core from the center of the lake were measured and show fine laminations to a depth of 150cm. From 150cm to 200cm the width variability increases, followed by another decrease. More massive and diffuse layers extend down to a depth of 275cm and are associated with two prominent peaks in the magnetic susceptibility profile. The deeper portions are finely laminated with intermittent thicker deposits. Visible sediment layers range from 0.3mm to 42.4mm with a mean width of 2.9mm and a standard deviation of 3.77mm. A low-resolution loss on ignition analysis shows values ranging from 0.5 to 2.5% with an overall decrease down core. Percent carbonate remains below 4% except for two large increases at 215cm and 425cm depth. Silts are dominant, composing 50 to 90% of the sediment composition, followed by sands and clay, both of which have significant variability down core.
Bibliography of Canadian Geomorphology