50 STRATIGRAPIIICAL GEOLOGV. 



large basin from which flow so many streams that form the Magalloway. 

 It is of a greenish black color, mottled with olive green. It is asbesti- 

 form where joints occur, and weathers to a reddish brown. It is un- 

 doubtedly a metamorphic rock, and probably formed from preexisting 

 silicates. There is also in this basin a green schist ; but going south-east, 

 the ridge that forms the water-shed between the Magalloway and Con- 

 necticut is composed of gneiss. Following this ridge southward, we 

 come to Mt. Carmel, which is a stratified diorite ; the flanks of the ridge, 

 running north-east toward the Magalloway, are gray siliceous schists. 

 Going south-west from the water-shed just mentioned, we pass over 

 Stubb hill, the ridge of Bosebuck mountain. Diamond ridge, and Magal- 

 loway mountain. All of these are composed of siliceous schists. Some 

 of these schists have the appearance of a dark quartzite, but particularly 

 on the west, in the joints, they contain lime as an incrustation. 



Lyman Group. 



On the line of Maine and New Hampshire, between the heights of 

 Mt. Carmel and Mt. Prospect, there is an axis. The rock is a gray sili- 

 ceous schist, which in places approaches novaculite. Though the strata 

 are nearly vertical, yet on Mt. Carmel the dip is northward, and on Mt. 

 Prospect it is southward. The distance between these points is 920 rods. 

 In consequence of the southerly dip on Mt. Prospect, we have a mountain 

 with a precipice almost perpendicular on the north side, something ex- 

 ceedingly rare in New Hampshire. On Mt. Bosebuck, about the same 

 distance south of Mt. Prospect that Mt. Carmel is north, the dip is north- 

 erly ; so that Mt. Prospect, with Mt. Bosebuck, forms a syncinal axis, or 

 there is a series of folds, and there has been an immense downthrow 

 north of Mt. Prospect. These rocks correspond to the Lyman group, 

 which is the upper member of the Huronian. Between Mt. Carmel and 

 Mt. Prospect there is a deep valley, and on the Little Magalloway, that 

 flows through it, there is a band of clay slate ; while near Mt, Carmel, 

 and forming the east end of the mountain, there is a greenish, indurated 

 rock, probably diorite. While the strike is only a little south of east on 

 the state line, as these rocks extend west and south, the strike becomes 

 more southerly. On the old "tote "-road, from Connecticut lake to the 

 Magalloway, it attains a great width ; and the general strike is N. 20° E. 



