GEOLOGY OF TIIIC WHITE MOUNTAIN DISTRICT. 12$ 



Clouds, but passed down at tlic gap between Mts. L^ranklin and Pleasant. 

 The rock is the usual mixture of andalusitc mica schists and granitic 

 gneisses at the starting-point, dipping N. 88° W., also 54° N. 48° W. near 

 by. These two mountains send out spurs into the valley, the northern 

 being longer, and the southern the steeper one of the two. About a 

 mile and a half down the valley between them the dip is N. GT)° W. 

 Lower down the dip is small to the north. The rock contains fragments 

 of an older schist in it. Beyond, there may be a south-westerly inclina- 

 tion, though this has not been satisfactorily observed. At a lower point 

 the dip is distinctly 60° N. ^2^° W. On the east side of Mt. Clinton, high 

 up, one can perceive from the valley a large, bare ledge. Where the 

 tributary, down which we have come so far, joins the main Mt. Washing- 

 ton river the ledges dip 30° N. "jt," W. Then, for half a mile, the schists 

 generally dip in the same general north-westerly direction, but there are 

 a few contorted dips in the opposite direction. The last ledge seen 

 before reaching the labradorite outlier dips 85" N. ST)° W. 



The following represents the appearance of the ledges down the val- 

 ley between Mts. Clinton and Jackson, before reaching Mt. Washington 

 river. At the beginning of the slope the strata are about vertical, with 

 a strike of N. 12° E. Beyond, the dip is 80° westerly, with irregulari- 

 ties in the direction, and there is andalusite present. Continuing down 

 the mountain's side we come to a cascade twenty-five or thirty feet in 

 height, at whose base enters the first important tributary from the north. 

 The schists dip 70° S. 48° E. The rock below becomes more mica- 

 ceous ; and many ledges resemble the darker colored varieties seen at 

 Nancy's brook. At the next fall, of over one hundred feet, the rock 

 changes, and much resembles the porphyritic gneiss. Crystals of ortho- 

 clase are abundant, the dip being 70° N. 83° W. The iiner-grained part 

 of this rock presents a slightly talcose aspect ; and our conclusion is, that 

 if it requires removal from the Montalban group, it may represent the 

 porphyritic member of the Ikthlchem gneiss. The schists at the falls 

 dip both east and west, the latter being lowest down, and contain quite 

 large plates of mica, with a curved trap dyke. Below the falls the schists 

 vary in mineral composition, and I have noted the presence of a very 

 large trappean mass. Next, the strata are fine-grained and much jointed. 

 The feldspar bunches recur again just before reaching the junction of 



