880 ANTARCTIC VOYAGE OF THE BELGICA. 



and the external forms of tlie .snow tields, as well as by the crevasses, 

 that we can picture to ourselves the form of the ground on which these 

 ice masses rest. 



Still it is possible to trace some of the broad lines of the irregulari- 

 ties of the relief, due to tectonic causes. The two principal islands of 

 Palmer Archipelago arc traversed in the direction of their length by a 

 chain of mountains having a Avell-defined direction from southwest to 

 northeast, with, I believe, a gentle curvature to the ciist. The Riscoe 

 Islands certainly form the southern prolongation of this chain, while 

 Trinit}^ Island is possil)lv that to the northeast. Moreover, from the 

 few geological data which I could collect this line of mountains foi'ms 

 likewise a zone of ancient eruptive rocks, Avith one or more volcanoes 

 of Tertiary, or possibly even of Recent date. Wiencke Island and the 

 northern point of the coast of Graham Land form a similar chain, 

 which runs in a direction parallel to the first. As regards the moun- 

 tains of Danco Land, the}^ form more important massifs of granites, 

 metamorphic, and sedimentary rocks, while farther inland there are 

 also some masses of gneiss, as is shown by the erratics derived from 

 that part of the country. 



I am led to believe that the more detailed study of the geology of 

 this "New Greenland" of the first navigators will ])ring to light anal- 

 ogies l>etween the mountain system of these lands and that of the 

 chains which form the southern extremity of the Andes, and that we 

 are now in a position to formulate and discuss the theory of the " Ant- 

 arctic Andes." The petrographic study of the rocks which I brought 

 back will give us some data to work from. I propose to call this S3^s- 

 tem of mountains the Copernicus Range, and in this way to intro- 

 duce into our geographical maps the name of the immortal Polish 

 astronomer. 



The glaciers of the antarctic lands visited by the expedition are very 

 characteristic, and differ completely in appearance from the Alpine, or 

 even the arctic glaciers. The line of perpetual snow running veiy 

 close to the level of the sea, and in places even at that level, one of 

 the special features of glaciers, and quite the rule in the case of Alpine 

 and arctic glaciers, is completely absent in the antarctic glaciers. 

 The terminal portion of the ice stream — that in which it is laid bare 

 and melts under the influence of solar radiation and the higher temper- 

 ature of the lower regions to which it has descended — which we have 

 come to regard as quite characteristic of glaciers, is almost entirely 

 absent. To their very extremities they are, in fact, included within 

 the region of accumulation of snow b}^ atmospheric precipitation. 

 This fact alone permits the occurrence on the antarctic lands of special 

 types of glaciers, the most remarkable of which is that of ice caps. 

 The stud}^ of the Alpine glaciers has led geologists to distinguish only 

 the three forms of "valley glaciers," "hanging" or "corrie glaciers," 



