Fossils from Lake Sediments in Northern Québec and Labrador: A Window into Past Climate Changes

Аннотация

... The overall objectives of my study are 1) to establish a high-resolution temporal reconstruction of environmental and climatic impacts on aquatic conditions at three sites, each at a different latitude and in a different ecoclimatic zone; 2) to develop a spatial-temporal image of postglacial environmental changes in the Québec-Labrador region through the use of radiocarbon dating; and 3) to compare the synchronicity of several indicators (diatoms, chironomids, and pollen) in order to assess differences between the responses of aquatic and terrestrial organisms to climate change. ... The first lake, K2 (informal name), is located at 58° 44' N, 65° 56' W, 6 km northeast of the town of Kangiqsualujjuaq and about 11 km southwest of Ungava Bay. The second lake, Oksana (informal name), is located at 54° 49 N, 66° 50' W, near Schefferville. The third lake, Lac au Sable at 51° 24' N, 66° 13' W, was sampled by researchers George A. King and Herb E. Wright (Limnological Research Center, University of Minnesota) and is located about 130 km north of Sept-Îles. The sediment cores from each lake were subsampled at 1 cm intervals, each representing a period of approximately 10 - 50 years. ... So far, diatoms and chironomids have been underexploited as biological indicators of change in northern Québec-Labrador, and they will be increasingly used in future research. ...