224 



shaped curves characteristic of the corroded phenocrysts of quartz- 

 porphyries do not occur) surrounded by rings of thin, strongly 

 refractive prisms, and felspar interspersed with a compact, fine 

 pigment, and in spots quite transformed through new mineral for- 

 mation. The basalt dike itself at the point of contact is a true 

 olivine-bearing augite-porphyrite, with a hyalopilitic ground-mass. 



In the isolated gneiss area of Liverpool Land, out by the 

 coast, the basalt dikes seem, curiously enough, to be very 

 scarce, which seems to indicate that the two large basalt areas 

 were not connected earlier. The dikes I saw showed nothing 

 remarkable. 



In the sedimentary formations basalt dikes occur both in 

 the Rode Ö conglomerate and the G. Leslie sandstone, according 

 to Bay, and also in the Jurassic strata of Jameson Land. 

 Here, however, it is almost exclusively in the shore cliffs at 

 Hurry Inlet that one has a chance of noticing them; we find 

 both dikes, and stratified, not lens-like, banks, so splendidly 

 regular that one is tempted to look upon them as volcanic 

 sheets contemporaneous with the surrounding Jurassic strata. 

 This, however, is not the case: occasionally one can observe 

 how they suddenly cut off the sandstone strata, or even that two 

 basalt strata cross over each other (cf. the fig. PI. XIV). A finer 

 example of typically intrusive sheets would be hard to find 

 elsewhere^). A specimen which I examined microscopically was 

 remarkable in that the augite, to an even greater extent than 

 usually, forms a kind of matrix, in which the lath-shaped 

 felspar-individuals swim, as it were. Fresh grains of olivine 

 were still visible^). 



^) The circumstances must have been observed already by Bay; cf. the 

 figure in Medd. om Grønland, XIX, p. 166. 



-) The interior of Jameson Land is so completely covered by post-tertiary 

 strata that one rarely has an opportunity of observing the basalt dikes. 

 On the other hand, I found in the N. part, as dikes and even small 

 masses in the Jurassic sandstone, curious alternatingly light and dark, 

 compact rocks recalling basalt; similar types are also found as blocks 



