218 



dikes further S. on the same coast, I may refer to my former 

 description of these rocks ^). 



Within this mighty area — the district where basalt 

 forms the rock bed, in the S. area alone, can be estimated 

 at 40,000 km^ — the basalts, in splendid development, show 

 the marked stratiform alternation of variously constituted sheets 

 which have so often been described from other places. My 

 investigation have not been extensive enough for me to con- 

 tribute anything to the problem the origin of similar basalt 



Fig. 4. Rounded gneiss hills (the first seen on the way southward from 



Scovesbv Sund) on the E. side of Kangerdlugsuak. 



G. Amdrup phot. 8: 8; 1900. 



plateaus. Nowhere did I come across transitions to the true 

 volcanic type. While dikes of basalt are very common, 

 even in the basalt itself, 1 could never with certainty point to 

 one so connected with a superposed sheet of basalt that one 

 could be sure that it had served as an eruptive canal for 

 the same. On the other hand in the dikes themselves there 

 often occur irregularities that point to the lava not having 



M Medd. om Grønland. XXVIII, 1 — 16. 



