Eratyki przewodnie w glinach morenowych Polski
Abstract
Fennoscandian indicator erratics in glacial tills of Poland.
S u m m a r y. Erratics analysis is one of the principal methods used to study glacial sediments. Usually, simplified petrography of gravel fraction is employed, whereas more advanced techniques, based on interpreting certain rock types of Fennoscandian provenience, are still rarely used in Poland. This is mainly due to the lack of training in classifying erratic rocks, what in turn is at least partly a consequence of the lack of appropriate Polish language atlases. We are willing to bridge this gap, presenting the 33 descriptions of the indicator rock types found in the Pleistocene sediments in Poland. Most descriptions have been illustrated with colour photographs, showing either the specimens from Poland, or the ones collected during our expeditions to Sweden, Denmark and Finland.We present the most important features, which allow to both identify a sample unambiguously and to tie it to a specific outcrop in Fennoscandia. Additionally, we include the geographic coordinates of the central points of source outcrops, used to define the theoretical pebble centres position (Lüttig 1958).
S u m m a r y. Erratics analysis is one of the principal methods used to study glacial sediments. Usually, simplified petrography of gravel fraction is employed, whereas more advanced techniques, based on interpreting certain rock types of Fennoscandian provenience, are still rarely used in Poland. This is mainly due to the lack of training in classifying erratic rocks, what in turn is at least partly a consequence of the lack of appropriate Polish language atlases. We are willing to bridge this gap, presenting the 33 descriptions of the indicator rock types found in the Pleistocene sediments in Poland. Most descriptions have been illustrated with colour photographs, showing either the specimens from Poland, or the ones collected during our expeditions to Sweden, Denmark and Finland.We present the most important features, which allow to both identify a sample unambiguously and to tie it to a specific outcrop in Fennoscandia. Additionally, we include the geographic coordinates of the central points of source outcrops, used to define the theoretical pebble centres position (Lüttig 1958).