chapter  Chapter 1
13 Pages

An outline of glacial indicator tracing

WithMatti Saarnisto

This chapter describes the methods employed in glacial indicator tracing, including not only boulders but also the general lithology of glacial sediments, their heavy minerals and geochemistry. The methods available to glacial geologist for ore prospecting have been used successfully in areas such as Finland, where the glacial sediment cover is thin or of moderate thickness. Glacial landforms are important for reconstructing directions of glacial movement. They can be investigated using air photography or topographic maps provided that these have adequate contour intervals. The landforms considered are of varying magnitude, from major glacially sculptured bedrock forms to glacial striae. The tendency for different minerals to become enriched in certain grain-size fractions during glacial transport has to be considered when tills are studied from the prospecting point of view. The transport distance is generally longer in glaciofluvial material than in the till from which it is derived and thus the source area is more difficult to assess.