2/2 SURFACE GEOLOGY. 



the quartzites a less distance. The origin of the Bethlehem gneiss is 

 not clear; — if from west of north, it may have come from the north part 

 of Haverhill, very near. If the current west of south brought any ma- 

 terial to the summit, the boulders would naturally have come from Beth- 

 lehem, less than twenty miles away. Upon Mt. Lafayette are many 

 boulders of the darker variety of Bethlehem gneiss, derivable either from 

 the east or west of north. A fine-grained granite, Huronian hornblende, 

 and gneiss occur about fifty rods below the top. Forty feet below the 

 top, on the south side, is a boulder of porphyritic gneiss. None of them 

 are necessarily great travellers, say twelve or fifteen miles from the 

 north or north-west. The Sugar Hill staurolite is found at the Eagle 

 lakes, indicating six miles travel to the south-east. This is different 

 from the striae on the mountain, which runs west of south. Both forces 

 must have operated here. At the first tank on the Mt. Washington Rail- 

 way, say 3,000 feet altitude, are stones of Essex county, Vt., pargasite 

 and delicate staurolite; at least, no other localities of these minerals are 

 known, a distance of twenty-eight miles north-west. At the third tank, 

 5,800 feet, are pebbles of Lancaster or Huronian rocks, that have come 

 nearly twenty miles. Near the top of Mt. Madison are handsome gran- 

 ite boulders, of such material as occurs a few miles northerly. On Red 

 hill, Moultonborough, are fine-grained granite, probably from Waterville, 

 black mica schist like that of the Coos group, trap, hornblende, Montal- 

 ban and Lake gneisses, all in place near by, except the second, which is 

 unknown short of forty-five miles to the north-west. Mt. Mote shows 

 slate from the upper Saco valley. From Mt. Chocorua I obtained a spark- 

 ling mica schist, which may have come either from the north-west or 

 the north-east. Lovcll's mountain in Washington shows mica schist and 

 gneiss boulders, which cannot be definitely located. On top of Mt. Ascut- 

 ney are argillaceous schist and Huronian diorite pebbles, the first from 

 the north, the second probably, not necessarily, from the same quarter. 

 On the top of the north Twin mountain are boulders of Bethlehem 

 gneiss from the north-west, ten to fifteen miles. The slide on the north 

 side has many Huronian fragments, that have come about twenty miles. 

 Cherry mountain summit shows Bethlehem gneisses from Jefferson, the 

 next town. There are boulders of porphyritic gneiss on top of Mt. 

 Gunstock. 



