Notities over heidegrond en hun ontginning en twee nieuwe zwerfsteentellingen in Drente

This paper, a sedimentpetrological study, deals with the results of two counts of Fennoscandinavian boulders, occurring in West-Drente, forming the central part of the northern Netherlands (table I). The method used was the 'four-groupssystem' of Professor Hesemann. A complete list with the results of all published counts is added; this list (table II), which is shortly discussed, shows the quite different origine of the boulder-associations in the glacigene deposits of the Netherlands. All counts concern boulders which are transported by the landice to the low countries; this transport may date back to the Pleistocene Riss glacial epoch (= Saalian).