TIIK I'l.KISTOt KNK SKI: IKS 'i.V, 



southern limit of tin- continent and continuous ire at the time of 

 it- maxim-.ini extension, whether Heating or resting on sea-floors, 

 is shown in Fig. 208. This southern limit passes through the 



>] Channel and up the valley of ilir Severn, then ai 

 Kngland to that of the Thames, through Helgium l>y l!ru--eU 

 and l>u--eldorf to the fool of the Westphalian Hills; round the 

 II '.',/. -Mountains (which are glaciated to a height of 1470 feet) 

 to the I-'iv. Mountains and the Riesen and Sudeten ranges, passing 

 l>y Cracow and Vladimir into the hasin of the Dnieper ;md out 

 again in an irregular line through Central Russia. 



Glacial Deposits. Many Swedish and German geologists 

 have endeavoured to educe some definite order of succession out of 

 the eongerie> of Glacial deposits which covers such a large part of 

 their respective countries. Most of the Norwegian and Swedish 

 geologists recognise two lioulder-clays, a lower bluish clay and an 

 upper clay which is generally of a yellow colour, but in many 

 parts of the region it seems difficult to distinguish them. In 

 Scania, however, the distinction is more clearly marked by the 

 frequent interposition of strati tied sands and gravels, and sometimes 

 of laminated clay containing remains of the dwarf birch and other 

 plants. There, are also long continuous ridges of morainic material, 

 one behind the other, which are regarded as marking successive 

 pauses in the recession of the ice-sheet. 



In Germany the evidence for two distinct boulder-clays seems 

 to be stronger, and some find reason to believe in a third. The 

 Lower " Diluvium " is the most extensive, and is described as a 

 bluish or brownish clay containing many boulders of Scandinavian 

 origin, and it is the southern border of this clay which is shown 

 on the map (Fig. 208). Above it in many places are stratified 

 deposits, generally sands and clays with occasionally beds of peat : 

 these contain plant remains and also the bones of Elephas antiquus, 

 E. primigenius, Rhinoceros tichorhinns, Cervus megaceros, and C. 

 eltiji)tn.<. The plants in these beds are specially remarkable because 

 they include not only pines and firs, but leaves of the aspen, 

 poplar, oak, hornbeam, ilex, Trapa natans, and a water-lily 

 (Cratopleura), the assemblage indicating quite a temperate climate 

 no colder than that of Germany at the present time. 



The Upper Diluvium (or boulder -clay) covers Denmark, 

 Schleswirk-Holstein, Northern (lei-many, and the Baltic provinces 

 of Russia, and is associated with mounds and ridges of terminal 

 moraines which mark the final stages in the retreat of the i<v- 

 sheet. One such ridge has been traced from near Netistrelitz in 

 Mi cklenburg, south-eastward to Oderberg, a distance of 3f> miles, 

 and probably reaches still farther. Borings have shown that the 



