78 STRATIGRAPHICAL GEOLOGY. 



none. A place where they are the most numerous is in the vicinity of 

 Mud pond, in Pittsburg, and the quartz is remarkably white and vitreous. 

 On a hill east of J. Young's, in Stewartstown, where there are veins, 

 chlorite is found associated with the quartz. 



At Dixville notch there are several interesting trap dykes. Near the 

 height of land in the Notch there are large, loose blocks, which have 

 come from a dyke above. The rock is basaltiform, and contains large 

 masses of augite and glassy feldspar, and resembles, according to Jack- 

 son, volcanic rocks more than any other found in the state. A similar 

 rock is found in the wall of Huntington cascade, south of the road below 

 the Notch. At the Flume, north of the road, just at the gate of the 

 Notch, there is a trap dyke, somewhat porphyritic, with feldspar crystals. 

 It is probable that, by the disintegration of this dyke, the Flume has 

 been formed. These dykes have cut through the schist and granite, 

 without apparently having disturbed or changed it. 



In Millsfield, south of the road near J. C. Sweatt's, a vein a foot in width 

 cuts through the green chloritic schist. It is composed of feldspar, very 

 white, mica, nearly colorless, vitreous quartz, and occasionally crystals of 

 tourmaline and garnets. A fourth of a mile east of Sweatt's, at the falls 

 on Clear stream, is a vein four feet wide cutting the schist. Here the 

 feldspar is white, the quartz smoky, the mica has a greenish tinge; and, 

 besides garnets with a resinous lustre, there are also small crystals of 

 beryl. Near M. Haynes's, in Stewartstown, there is a trap dyke four 

 feet wide, which we were able to trace a quarter of a mile. It runs 

 nearly parallel to the strike of the schist. 



Near the head of Blodgett brook, in Columbia, there is a dyke of trap 

 cutting the granitic rock. It is amygdaloidal, and contains epidote and 

 calcite, and, in places, distinct hornblende crystals. In the southern part 

 of the town, near W. Kimball's, where the granite comes in contact with 

 the schist, it sends off veins into the surrounding strata. These veins 

 are finer grained than the granite mass. This is supposed to result from 

 the more rapid cooling of the mineral constituents. At Groveton, on the 

 Grand Trunk Railway, there is a vein of hematic iron ore, which, with 

 the quartz, forms a kind of breccia. In Stark, in the wall of the Devil's 

 Slide, near the eastern extremity, there is a dyke of diorite which is un- 

 like any that we have seen elsewhere. It is porphyritic; and the feldspar 



