122 STRATIGRAPHICAL GEOLOGV. 



by its dome-shaped summit. [See heliotype, Vol. I, p. 220.] The top is 

 well covered by drift, not of great thickness, nor sufficient to prevent the 

 acquisition of information about the rocks, which are granitic and coarse 

 mica schists, with ferruginous admixtures. Dykes of trap occasionally 

 occur all along the range, one in which numerous jointed seams divide 

 the rock into small pieces. On the south side of iVIt. Pleasant, as well as 

 upon Mt. Franklin, there are numerous large concretion-like bunches, two 

 or three feet across, in the common schists. The layers in these bunches 

 usually have a different position from that of the adjoining strata; and 

 the material between is charged with ferruginous compounds. The dip 

 changes at the valley between Mts. Pleasant and Clinton to 68° S. 47° E., 

 and ferruginous strata are to be noted here. Half a mile before coming 

 to Clinton the dip is 80° N. 73° W. Mt. Clinton shows granitic and de- 

 composing gneisses. The dip is N. 73° W. at variable angles, and the 

 direction is also irregular. Between Mts. Clinton and Jackson the rocks 

 stand about 80° N. 62° W., and are coarse feldspathic mica schists. After 

 passing Clinton the following successions of strata occur on the bridle- 

 path : At three and a half miles, near the summit, micaceous rocks, with 

 acicular hornblende crystals; at three and one twelfth miles, granitic 

 gneiss ; at three and one sixteenth, granitic gneiss ; at two and a half, 

 coarse mica schists ; at one and a half, granitic gneiss coarser than the 

 "Concord;" the same at half a mile, with the dip 56° W. and S. 80° W. 

 On the east side of the Crawford house is Gibbs's brook, which falls over 

 ledges of coarse granitic gneiss and grayish mica schists, half a mile or so 

 from the hotel, and the place is known as Gibbs's falls. This location is 

 just below the half-mile station on the bridle-path mentioned previously. 

 At the Gate of the Notch the rock is the feldspathic mica schist of the 

 Montalban series. The railroad excavations are making the character 

 and position of the rocks much better known here than formerly. The 

 proper dip seems to be 65° S. 80° W. The Elephant's Head is composed 

 at its northern base of a granitic gneiss, which has been extensively 

 utilized for the building of railroad culverts. Other rocks of different 

 ages crowd themselves into the Notch, which must be noticed further 

 on. A trip up Mt. Webster, starting from the road at the Silver cascade, 

 revealed the following facts : Upon the road there are Montalban schists. 

 At the base of the cascade there is a granitic rock, with scams dipping 



