426 THE CANADIAN NATURALIST. [Vol. viii. 



variety, the one that was analysed, is 2.78. A darker, finely- 

 granular variety is 2.89 (the sp. gr. of the common dark violet 

 gabbro of Hiasen is 3.08). The peculiar relationship which 

 exists between the " spotted gabbro " and the apatite bearing veins 

 in several deposits will be more closely discussed further on. 



The ordinary dark violet gabbro, moreover, also occurs at four 

 points near Oedegarden. 



The small zone of "spotted gabbro" is intersected by two 

 coarsely granular veins of granite, which, judging by its appear- 

 ance, belong to the older granites that are never otherwise met 

 with outside of the primary hills. This circumstance indi- 

 cates that the gabbro here must be older than the gabbro masses 

 that intersect the Sparagmite and Silurian formations in other 

 parts of our country. 



The rich veins characteristic of this locality occur in the 

 "spotted gabbro" — not at all in the strata of the primary 

 hills, or in the granite or in the small portions of common dark 

 gabbro. They can be briefly designated as apatite-hearing mica- 

 veins. A brown magnesia-mica is in many veins almost the 

 only mineral, generally accompanied by green enstatite along 

 with small lumps of apatite. As the quantity of mica decreases 

 and that of apatite increases, the character of the veins changes. 

 The richer veins are distinguished by the fact that the mica 

 almost exclusively occupies the sides, and apatite the centre. In 

 regard to the relative position of the veins a certain regularity is 

 observed, as they almost all dip slightly towards the ridge, viz., 

 towards S. S. W., S. and S. E. 



The veins are very numerous, and, moreover, so often branched 

 and connected by cross- veinlets, that the entire deposit resembles 

 a net of veins covering a stretch of 1600 meters. 



After these brief preliminary remarks, we bring the reader to 

 the largest and most interesting veins. 



The first vein to be described is a mass of mica about twelve 

 feet wide, chiefly in fine scales which contains crystals of a grey- 

 ish-green hydrous enstatite and lumps of apatite several feet in 

 diameter. Some of its finer veinlets consist of raven-black horn- 

 blende, instead of mica. The country rock — the " spotted gab- 

 bro " — is here coarsely schistose, and contains very small grains 

 of rutile, arranged parallel to the other minerals. The cleavage, 

 which is not parallel to the strike of the vein, becomes in the 

 case of one of the stringers gradually more indistinct, until the 



