XL] GRANITES AND GRANITIC VEIN-STONES. 209 



sometimes to the entire exclusion of quartz and feldspar, both 

 of which minerals are, however, frequently intermixed with 

 the preceding species in the same aggregate. In one example, 

 in Burgess, Ontario, the sides of a large vein are occupied by 

 a mixture of calcite and apatite, while the centre is filled by a 

 vertical granite-like layer of reddish orthoclase, with a little 

 quartz and green apatite. Of another vein in the township of 

 Lake, in Ontario, one portion was found to consist of calcite 

 with yellow phlogopite, while an adjacent part consisted of 

 quartz, with brown tourmaline, bismuthine, native bismuth, 

 and graphite. 



37. The resemblance between the minerals of these Lau- 

 rentian vein-stones and the same species brought from Norway 

 was noticed so long ago as 1827, by Dr. William Meade 

 (American Journal Science (1), XII. 303). Daubree, in his 

 account of the metalliferous deposits of Scandinavia, published 

 in 1843 (Annales des Mines (4), IV. 199, 282), has given us 

 a careful description of the veins from which these minerals 

 are derived. From this, together with the observations . of 

 Scheerer and Durocher, we are enabled to compare these vein- 

 stones with those of the Laurentian rocks in North America, 

 and show, as I have in the essay above referred to done 

 in detail, and for each principal species, the great similarity 

 which exists between the two. In the so-called Primitive 

 Gneiss formation of Scandinavia these veins occur either in 

 gneiss, or in a gneissoid rock consisting of various admixtures 

 of pyroxene, hornblende, garnet, epidote, and mica, the whole 

 associated with crystalline limestones. The veins which abound 

 in the gneiss near the iron-mines of Arendal, in Norway, accord- 

 ing to Daubree, though occasionally containing calcite, apatite, 

 hornblende, and scapolite, are sometimes destitute of all calca- 

 reous and magnesian minerals, and become granite-like aggre- 

 gates of orthoclase and quartz. He hence describes these veins, 

 as a whole, though frequently abounding in lamellar calcite, as 

 essentially granitic in character. As already noticed in 8, 

 Daubree agrees with Scheerer in regarding these vein-stones as 

 produced by a process of secretion, in opposition to Durocher, 



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