Volume 5, Number 2, June 1978

EN:

Thermoluminescence (TL), is nowwide-ly used in archeology for the absolute dating of ancient pottery. During the last decade, particularly in the USSR, it has also been applied with mixed success to the dating of Pleistocene loess, buried soils, glaciofluvial, glaciolacustrine and marine deposits, and even tills. The purpose of this paper is to stimulate investigation of the application of this method to geological problems. Absolute dating methods beyond the radiocarbon dating range are urgently needed, particularly in the Pleistocene stratigraphy of North America. Therefore, even those relative or semi-absolute dating methods which have the potential eventually to provide reliable absolute dates, have to be investigated. The TL dating method belongs to this category, with its dates ranging between 103 and 10^ years B.P.

Major problems to be investigated concern the fact that Pleistocene sediments do not always have a well established zero point for TL, and post-depositional changes may also have a profound effect on the TL.

Quartz is one of the most suitable materials for TL dating known so far, and its use has been investigated recently at the Institute of Geology in Tallin. The best results have been obtained by using quartz grains 100-140 ìéç in size, after their outer layer has been removed by HF to exclude the TL caused by « -radiation.

EN:

Elevated marine features occur in Atlantic Canada and those that appear to represent the upper marine limit and have been dated cluster around 13,000 + 500 years B.P., with a range from 14,000 to 11,500 years B.P, Although the scatter of dates precludes the drawing of truly synchronous isobases, simple isopleths can be drawn and show regional variations in uplift that are probably related to ice loads Two main centres of maximum uplift are shown, namely New Brunswick, and northern Newfoundland - southeastern Labrador. The uplift in southwestern and northern New Brunswick is probably related to strong ice outflow in those areas, while thick Labrador ice caused rebound to increase towards the north in Newfoundland, A northward deflection of the isopleths in the Gulf of St. Lawrence suggests that it was free of grounded ice during the late Wisconsman.