Erratics of Northern Germany
Gisela Lunkwitz and I spent an afternoon in early August 2015 tracking down two among the largest glacial erratics in Germany. They are known as the Rauen Stones and can be found in a wooded area near the small town of Rauen, about seventy kilometres east of Berlin. Geologists have established that the huge boulders are made of granite from Karlshamn in southern Sweden. The glacier that moved them south is thought to have travelled at about 100 meters a year and taken 6,000 years to reach their present position. Experts have identified the origins of about ten percent of the large number of such erratics (generally much smaller) in Brandenburg. In 1831 a bowl weighing 75 tons was made from one of the two and transported to Berlin by barge. After polishing, the bowl was place at Berliner Lustgarten in front of the New Museum after it was found to be too big, nearly seven meters wide, to be placed inside the museum as planned.
Only in 1875 did Otto Torel, a Swedish geologist, recognize that the parallel markings on stones he examined in Brandenburg resulted from glaciers. The last glacial period in northern Europe (the Weichselian glaciation) ended almost 12,000 years ago which coincided with the end of the Pleistocene and start of the Holocene epochs. Glaciers had covered western Europe during previous ice ages; the last one to reach northern Brandenburg, the area around Berlin, was 20,000 years ago. The huge mass of moving ice, often over a hundred metres thick, has shaped the landscape and left undulating hills, low rounded valleys and over 800 lakes and ponds. Together with the extensive woods they make Brandenburg a favourite place for walkers.
Text Peter Whiteley, photos Gisela Lunkwitz