398 THE CANADIAN NATURALIST. [D 



ec. 



The bluish crystalline limestone is mixed with grains of greenish 

 pyroxene, and includes nodular granitic masses of white crystalline 

 orthoclase with quartz, enclosing large plates of graphite, crystals 

 of hornblende, and more rarely of apatite. These associations of 

 minerals are met with in the granitic veins of the Laurentian 

 limestones, to be noticed elsewhere. The limestone of Lewiston, 

 however, appears to be included in the great mica-schist series of 

 the region ; where similar beds, though less in extent, are met with 

 in various places, sometimes associated with pyroxene, garnet, 

 idocrase and sphene. A thin band of impure pyroxenic limestone, 

 like that of Lewiston, occurs with the mica-schists on the 3Iaine 

 Central Railroad, near Danville Junction, and beds of a purer 

 crystalline limestone were formerly quarried in the south-east part 

 of Brunswick, where they are interstratified with thin-bedded dark 

 hornbiendic and micaceous gneiss, dipping kS. E. at a high angle. 



§ 19. At Danville Junction strata of hornbiendic and mica- 

 ceous gneiss, passing into mica-schists, dip S. E. at moderate 

 ancles, and include huge veins of endogenous granite. Two of 

 these appear in the hill just south of the railroad station, appar- 

 ently running with the strike of the beds. They are seen to rest, 

 upon the mica-schist, and in one of them a mass of this rock, three 

 feet in width, is enclosed like a tonsue in the granite, which has a 

 transverse breadth of about seventv-five feet. Notwithstanding 

 the apparent intercalation of these granitic masses the proof of 

 their foreign origin is evident in a transverse fracture and slight 

 vertical dislocation of the mica-schist, around the broken edges of 

 which the granite is seen to wrap. The endogenous character of 

 this granite is well shown by its banded structure ; belts of white 

 quartz some inches wide alternate with others of coarsely cleavable 

 orthoclase, while other portions hold black tourmalines and garnets 

 of considerable size. 



The evidence of disturbance of the strata in connection with 

 these endogenous granites is seen on a large scale at the falls of the 

 Sunday River in Ketchum. There, mica-schists and gneisses, 

 similar to those already noticed, enclose great masses of endoge- 

 nous granite, which are seen to be transverse to the strata. On 

 one side of such a mass more than sixty feet wide, the schistose 

 strata are twisted from their regular N. E. strike to the N. W., 

 and so enclosed in the granite as to appear as if interstratified 

 with it for short distances. The banded structure of the trans- 

 V3rse granite veins is here very marked. Some portions present 



