2. Workshops: Summaries of discussions WORKSHOP 1" TILL GEOCHEMISTRY IN MINERAL EXPLORATION

The basic differences between the application of till geochemistry in Finland and Canada are that (1) there is far less integration of glacial geology and geochemical exploration in North America than in Finland and (2) the application of new glacial sedimentology models and examination of basic assumptions about the history and dynamics of Scandinavian ice sheets are less emphasized in Scandinavia than are similar subjects in North America or the rest of glaciated Europe. The history of the application of glaciology and geochemical techniques to mineral exploration in Finland was discussed by L.K. Kauranne (Finland). He pointed out that the displacement of boulders was noted as early as 1740 by Daniel Tilas. By the 1950's geochemistry began to be applied to glacial deposits, and it was realized that samples may not have been all from the same depositional environment. Furthermore, it was recognized that there were probably more glacial events than the one great ice advance that had been supposed in the classical Scandinavian glacial model. In the 1970's systematic sampling of till began in Finland, largely financed through funds from unemployment programs. This sampling has continued at an ever increasing rate, but funding now comes directly to the Geological Survey. Regional geochemical mapping has been instituted recently at a density of one sample per 4 km 2. There has been good cooperation among the Scandinavian countries, which has culminated in the multimedia reconnaissance sampling program -"The Nordkalot t Project" -being carried out in northern Finland, Sweden, and Norway. J. Bergstr6m (Sweden) described the systematic geochemical mapping program carried out in Sweden since 1978. In this program, stream humus and peat are collected to find evidence of anomalous concentrations of labile economic minerals, and till is sampled to find concentrations of resistate minerals. W.O. Karvinen (Canada) pointed out that the rather thin and continuous till sheets in Finland, with their general lack of cover by extensive late-glacial lake or marine sediment, makes exploration somewhat more straightforward than on the Canadian Shield, where till thicknesses are variable, and large areas are covered by thick mantles of lacustrine or marine clay or by glaciofluvial and associated wind-blown sediment. The chairman then showed several examples of depositional environments around modern glaciers in northern Canada (Baffin Island). In these