114 Macfarlanc on the Primitive Formations 



they been studied or described so minutely * Naumann entitled 

 this district, the Nummedal and Tellemarken Quartz Formation ; 

 Keilhau described it as the Goustafjeld Region, from the mountain 

 which is its most distinguished topographical feature ; while Dahll 

 somewhat indefinitely calls it the Tellemarken Slate Formation. 

 The rocks which constitute this group are the following : 



1. Quartzite or quartz slate. This, the most widely distributed 

 rock of the group, occurs in the most multifarious varieties. 

 Pure quartz, with a granular structure and glassy lustre, of con- 

 siderable transparency, and of a white or greyish-white colour, is to 

 be found in beds of great thickness. Fine-grained quartz, with 

 a fatty lustre, and rose-red or flesh-red in color, is also observed in 

 equally powerful beds. The most common varieties are however 

 the splintery, grey, and slightly micaceous quartzites, which are 

 known as quartz slates. Amongst the more impure varieties, 

 talcose, feldspathic, and hornblendic quartzites are to be distin- 

 guished. 



2. 3Eca schist, differing considerably in general character from 

 that which occurs in the Primitive Gneiss Formation. The broad- 

 leaved very micaceous variety, with garnets, which is common in 

 that formation, has not been observed at all in this quartzose 

 series. In the constitution of the mica schist belonging to the 

 latter, quartz greatly preponderates, and the rock differs from 

 quartz slate, only in containing a somewhat larger quantity of sil- 

 ver-white or brownish-black mica. 



3. Gneiss may be also said to occur in this group, but of a 

 -character widely different from what is usually understood by 

 this term. It is finer grained and less slaty than the characteris- 

 tic primitive gneiss, while the feldspar and quartz, and especially 

 the latter, greatly preponderate in quantity over the mica. This 

 latter mineral, which plays such an important part in the compo- 

 sition of ordinary gneiss, is very little developed, and hornblende 

 is never found replacing it ; so that nothing resembling hornblendic 

 gne^'ss is found in this group. 



4. Hornstone and hornstone porphyry , passing into jasper, often 

 occur, and seem to consist of the same minerals, and in the same 

 proportions, as the two last named rocks, but so fine grained that 

 the species are no longer recognizable. The mica schist is seen 



• According to Keilhau, the district in West Finmark and Quaenanger, 

 in which the Alten Copper Mines occur, belongs to this group. It ia 

 probable also, that another district to the east of the North Cape is of 

 the same formation. 



