118 



is here coarser, and contains imbedded masses of resinous quartz and 

 dark blue slate ; farther on it is darker and finer, with clay galls, and 

 the dip again appears to be toward the slate, but the stratification is 

 obscure. In front of the first waterfall, amid a group of birch trees, 

 a mass of quartziferous horn stone porphyry lies across the bed of the 

 stream, but seems to terminate against the bank on the west side 5 

 on the east side its extension cannot be traced, so that most probably 

 it is not a dike. It is a beautiful rock, and if readily obtained in 

 quantity might be used for ornamental purposes. The base is a 

 dark reddish hornstone, containing crystals of glassy felspar, and 

 round bits of quartz. There are beds of conglomerate here ; and 

 the strata lean toward the slate, but less " end on ;" the dip being 

 about 30 W. of magnetic N. 



We are now approaching the junction of the old red sandstone 

 with the slate; but as this is not well seen in the bed of the main 

 stream, it will be more instructive to diverge to the left, up the 

 course of the west branch, as far as the dark brow of slate, where 

 the hill suddenly rises. Passing up the bed of this west-burn, we 

 find the common red rock and conglomerate succeeded by flinty or 

 quartzose sandstone, obviously metamorphic. The cause of this 

 change is soon discovered. At a waterfall on the burn there is an 

 outburst of a peculiar granite amid the sandstone strata. This is 

 an intimate mixture of quartz and felspar, without mica; in fact, the 

 Surite or Weisstein of mineralogists. It extends many yards in the 

 bed and banks how far cannot be determined. Between it and the 

 rocky brow, which is formed of the common dark slate, there are 

 various metamorphic beds, conducting us by insensible gradations 

 into the true slate. Some of these are white and gray flinty slates, 

 others fine-grained hard sandstones. It is thus difficult to decide 

 to which series the beds ought to be referred. The strata have been 

 assimilated by the metamorphic action to which both series have 

 been alike subjected. A similar case occurs on the White Water, as 

 already noticed (Art. 52, p. 76). 



Returning now to the bed of the main stream, and entering it 

 some way above the waterfall at which we turned off", we find similar 

 white and gray quartzites about fifty yards in front of a deep chasm, 

 with a waterfall, cut out of the slate rock. The sandstone is not 

 seen in close proximity ; but the junction must be near, as this is 

 the first point at which the slate appears in the bed or banks. 

 Two dikes of greenstone, from opposite sides of the pool, unite at 

 the edge of the fall, twice bifurcate, and twice unite again, enclos- 

 ing two long elliptic masses of altered slate, and then continue as 



