Mølen, The Great Glacier´s rock collection

Mølen is a part of one of the world´s largest natural monuments from the last Ice Age!

The melting and retreat of the huge glacier covering Scandinavia by the end of the last glaciation was discontinuous. In the periods when melting was low, the ice margin became fixed to certain positions. the glacier transported continuously sand, pebbles and cobbles to the ice margin where gravel ridge were formed and where the position of the glacier was fixed for a period of time.

Between 12.650 and 12.350 years before present, i.e. for a period of 300 years, the the ice margin was fixed to a single position. Then a gigantic ridge of gravel formed at the ice margin all around Scandinavia. In Southeastern Norway, this ridge is called the "Ra" and Mølen is a part of this huge ridge.

At Mølen, and and elsewhere in the "Ra"; there are rocks from various places and of different ages and geological origin. Among the cobbles at Mølen, you may find at least 100 different types of rocks. We can identify many of these, and then we can find out from where the glacier picked these up. Some characteristic rock types are: Quartzites from Telemark, Gneisses from Kongsberg and Meheia, Limestone from Grenland, Sandstone from Ringerike, Granite from Drammen and Rhomb porphyry from Vestfold. The most common rock types among the cobbles are larvikites and various syenites. This is no surprise since these rocks are found in the hills just north of Mølen. The most exotic rock found is flint. The flint possibly arrived as stowaway cobbles frozen into ice bergs drifting from Denmark.

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