>.><^l» 



^ «' 





OF DISKO ISLAND/ 



26^ 



9l 



K*. 





M' 



usually forms the summits of these hills, by another seam of 

 the same ferruginous substance, of a brownish colour. 



The mountain called Ounartorsak, near Godhavn, presents 

 the following proportions in one of its precipices: (See Plate 



Basalt, in columns of from three to seven sides, with some 



crystals of felspar. 

 Reddish-brown ferruginous clay. 

 Amorphous basalt, with geodes of radiated mesotype. 

 Reddish-brown ferruginous clay-. '' ' ^"r »■• . 



Amygdaloid. .*„ Reddish-brown wacke, contalning'stilbitei mesotype," &c. 



»»■. 



Basalt, 

 amorphous. 



Trap-Tuff. 

 Basalt-Tuff. 



^ 



•^%**.*v*>* 



The. last with apophyllite, &c- 

 Granite, with gneiss. 



# 



'«• 



m.: 



All the basalt of Disko is magrietFc. That found in the 



l^ost elevated situations is most so; the fallen masses dispersed 



around the base of the mountains having more power over the 



needle than the others. 



*- The mountains of Disko are almost all flat at the top, and at a 



distance present the appearance of large houses. It was only in 



ahe Waygat, and in the Bay of St James, (Omenak's Fiord), 



mfi where I observed pyramidal and conical summits. Mannik, a 



**(^ flftountain in Waygat, (see Plate XVII.), is terminated by an im- 



Ijfr jA^ense basaltic pyramid of four sides. On the summits of all the 



^ •*;Biountains which I ascended, I found numerous rolled masses 



of primitive rocks, often of considerable size, and of a weight 



^ beyond my power to move. These masses consisted either of 



jif. granite, gneiss, mica-slate, siliceous-schist, quartz, or hornstone. 



Porphyry-slate is the rarest rock among those of the trap-for- 



• mation in Greenland. Although I ascended several of the 



' mountains, I found it only in two. Unknown Island and Hare 



Island, to the north of Disko ; and there it occupied only the 



summit. 





■V- 



