358 CLIMATIC CONDITIONS OF THE GLACIAL EPOCH. 



oflF and thus given rise to the debris and soil which now form a superficial 

 coverini!; lor the solid rock beneath * 



It is owing to these differences of opinion as to what is the work of water 

 and Avhat that of ice, that opinions vary considerably in regard to the extent 

 of the area covered by the Alpine glaciers at the time of their greatest devel- 

 opment, and it will be easily understood that at the present time it is quite 

 impossible to give an accurate representation of the facts on a map. For 

 doing this there will not be available material, vmtil more unanimity prevails 

 amonir seoloa-ists in regard to erosion and the accumulation of detrital ma- 

 terial. As an illustration of these diflficidties a few remarks may be made 

 bearing on the question whether the ice masses on tlie northern side of the 

 Alps, in Bavaria, united in a confluent sheet at the base of the range, and 

 made their way over the comparatively level land to the north. 



F. Stark made a detailed examination of the north side of the Alps be- 

 tween Salzburg and Munich and has published a map giving " an ideal repre- 

 sentation of southeast Bavaria during the Glacial epoch [Eiszeit]."t On this 

 map the glaciers which once occupied the valleys of the Salzach, the Inn, 

 and the Isar are indicated as having at the time of the greatest extension 

 advanced beyond the base of the Alps, to a distance, in places, of three or 

 four German miles, all the valleys on the range above having, as is supposed, 

 been filled with ice to a great depth. The old termiual moraine of this 

 glacial sheet is represented as forming a well-marked topographical feature 

 of the region, extending in grandly regular scalloped forms along the range. 

 A comparison of Stark's map with the minutely -detailed topographical sheets 

 published by the Bureau of the Bavarian General Staff indicates that this 

 line of elevations does not in reality exist; at least, nothing indicating it is 

 laid down on the official map.$ Nor did an examination made by the 

 pi-esent writer along a portion of the supposed terminal moraine reveal 

 any other topographical features than those given by the government 

 surveys. Large masses of detritus are piled up at the base of the range, 

 which detritus is thoroughly water-worn, and in general distinctly strati- 



* " Sans glacier pas <k Imne glaeiaire, la roche a mi partout, et si le glacier ne I'a pas deposee diiecteinent, 

 c'est lui qui est I'auteur, le fabricant de cette terre que nous cultivons." DoUfus-Ausset, in Mateiiaux pour I'Etude 

 des Glaciers, Tome V. p. .351. 



t Zeitschrift des ileutschen Alpeuvercins, Jahrgang 1S73, Band IV. pp. 67-78, Die bayerischen Seen und die 

 alten Moranen, Eine Erlauterung zur Karte : " Ideale Uebersiclit von Sudostbayem zur Eiszeit." 



t Tliis is in striking contrast with the facts on the south side of the Italian Alps, where the terminal moraines 

 are reprpsented with perfect distinctness on the official topographical maps of the region. 



