330 GUNNAR HOPPE 



above the surface of the sea); this seems to be especially true in coarse- 

 grained rocks, in other areas, however, quite well preserved striae appear, 

 even after 10,000 years. Striae may also be preserved for long periods of 

 time on outcrops of quite soft rocks, particularly where these rocks are 

 fine-grained and the surfaces are well polished by the ice. Such observations, 

 however, do not change my opinion that glacial striae on exposed rock 

 surfaces cannot have survived since the Riss Glaciation (possibly with 

 extremely rare exceptions). However, the discussion would be easier if the 

 weathering of rock surfaces — including the destruction of striae — could be 

 illustrated by quantitative data. 



Andersen (1954, 1960) has investigated the end moraines of southwestern 

 Norway. Outside the Ra moraines, 10,300 to 10,800 years old, are three sets 

 of end moraines. These are partly below sea level, and they have been tenta- 

 tively dated as being 12,500 to 14,000 years old by Andersen. His very 

 cautiously expressed conclusion is that the front of the inland ice sheet during 

 earlier stages of the Last Glaciation was far outside the present coastline. 

 This conclusion fits well with the idea expressed at different times (Hoppe 

 1959) that the Scandinavian and British ice sheets were connected during 

 WUrm time, as well as during earlier glaciations. Recently Valentin (1957) 

 has advocated this connection on the basis of studies of the morphology of 

 eastern England and the bottom topography of the North Sea (Fig. 4). This 

 interpretation is also supported by the pattern of glacial striae in the Shetland 

 Islands, presented more than 80 years ago by Peach and Home (1879) which 

 clearly demonstrates an ice sheet moving westward, whose front retreated to 

 the east (Fig. 5). If the two ice sheets coalesced, it is most unlikely that ice- 

 free foreland refugia existed in western Norway ; therefore the Shetland Islands 

 may play a decisive role in the refugium discussion, and thorough investiga- 

 tions there must be considered very desirable. 



3. Foreland refugia in northern Norway. Thanks to studies of end moraines 

 and strandlines in combination with C^^ datings the glacial history of northern 

 Norway has become estabhshed on a firmer basis during the last few years, 

 Marthinussen (1960, 1961), Andersen and Feyling-Hanssen (both quoted by 

 Holtedahl, 1960), and Bergstrom (pers. comm.) have definitely demonstrated 

 the position and age of a well-developed "Ra-line" of end moraines as well 

 as the existence of older end moraines outside. The conclusion of Marthinus- 

 sen (1960, p. 421) concerning Finnmark, based in part also on the degree of 

 weathering and the occurrence of glacial striae and erratics, is that "there can 

 be no doubt but that the ice sheet of the last glacial period at its maximum 

 has covered all the present land". According to the investigations by Berg- 

 strom, the Lofoten and Vesteralen Islands have glacial erratics of continental 

 origin (conclusion by T. Vogt, according to Bergstrom, pers. comm.) on the 

 higher peaks, showing clearly that these islands must have been covered by an 



