( 529 ) 



juxtaposition and intermixture, which proves tliat they must have 

 been carried together and at the same time to the place Aviierethey 

 are found at present. From the shape of the front moraine, we con- 

 clude that tiie direction of the transport was from the North-East. 

 The erratics nowadays found at the surface have been gradually 

 dennded by the action of water and wind. It is therefore evident 

 that originally these erratics were transported much farther to the 

 North and East, than their present place of deposit, because they 

 were seized by the advancing Baltic icestream ami carried along 

 together with the material of its moraine. We are therefore justified 

 in fixing the period of the transport of the boulders from the Rhine 

 and Meuse at the commencement of the epoch of maximum glaciation 

 (Saxonian). 



A far greater difficulty presents itself when we attempt to deter- 

 mine in what way this transport has taken place, for it can only 

 have been effected by the agency of a river or a glacier. The 

 hypothesis that all these boulders should have been carried along 

 by the Meuse in its downward course, is scarcely admissible. Even 

 leaving out of account the finding of rocky fragments from the 

 Ardennes on the strands of Goedereede and Voorne — not to 

 speak of Suifolk, in Englaiul — there remains a large tract of land 

 105 K.M. long stretching from Utrecht to Eibergen, over which these 

 erratics are dispersed in the shape of a crescent. If carried by the 

 Meuse, its mouths must have extended over a very large area. But 

 a greater objection to this theory is that, in that case, they must have 

 been transported across the Rhine (at present the IJsel) because 

 rocks of this kind are found at places to the East of this river 

 (Doetichem, Eibergen, Markelo). Finally, some of these blocks are 

 so large that they could not possibly ha\'e been transported by a 

 river. Besides, some of them present no marks of polish, which is 

 another argument against their transport by running water. 



For the better understanding of these objections we cpiote a few 

 examples from tlie Province of Limburg and the Campine. A. Erens 

 found ill the environs of Maastricht numerous large blocks of Cam- 

 brian quartzites, one of which was 3 M. high, 2,6 M. long and 

 0,6 M. in width, computed to weigh about 12400 K.G. '). More 

 important still are the blocks of sandstone found in the diluvium 

 of the Campine at Holsteen-Molenheide, near Zonhoven, in the neigh- 

 bourhood of Hasselt, E. Dklvaux noticed blocks measuring from 4 



1) Note sur les roches cristallinus 1. c. p. 412, 417. Mr. L. Rutten informed 

 me tliat in the neialiboiirliood of Sittard similar boulders reach a diameter of 

 ± a M. 



37* 



