223 



samples collected have been described by Böggild^), following 

 whom I add the following list: 



Henry Land: Quartz, Chalcedony, Thaumasite, Chabazite, 

 Levynite, Desmine, Scolecite, Analcite, Heulandite, Laumontite '^). 



Turners Island: Quartz, Chalcedony, Thaumasite, Des- 

 mine, Scolecite, Natrolite, Mesolite, Analcite. 



С Brewster: Chalcedony, Desmine, Natrolite, Mesolite, 

 Analcite, Apophyllite, Heulandite. 



Moreover, we may mention that on Sabine I. within the N. 

 basalt area, Scolecite and Desmine were found. 



It still remains for me to deal with the qualities of the 

 basalts when they appear as dikes or in contact with other 

 rocks. Such dikes within the gneiss are in many places ex- 

 ceedingly common, for instance, in certain parts inside Scoresby 

 Sund, and also, according to Amdrup, at the S. boundary of 

 the basalt area. These dike basalts are, to judge from the 

 samples [ saw of them, fresh, clearly crystalline, typically 

 developed plagioclase-augite rocks, and it is especially charac- 

 teristic that, in contrast to the sheeted basalts, fresh olivine 

 almost always was observed here. 



From Danmark I. Bay^) brought back a specimen of the 

 contact itself between gneiss and a basalt dike. The former 

 at the point of contact is almost irrecognizibly transformed 

 and forms a mass that reminds one somewhat of a porphyry 

 breccia; the "matrix", probably through fusion of basaltic 

 material, has received a basic composition, while the irregular 

 "fragments" lying in it are composed of the strongly changed 

 remains of the original rock: quartz in individuals strongly 

 corroded bv fusion and showing sinuous outlines (the bottle- 



') Medd. om Grønland, Vol. XXXII. 



-) Laumontlte, which is by no means common in Greenland, and was 

 not seen before on the E. coast, occurs very plentifully in the breccia 

 in the hanging wall of the hot spring mentioned above. 



^1 Medd om Grønland, XIX, p. \ö2. 



