GEOLOGY OF THE WHITE MOUNTAIN DISTRICT. lOQ 



of Haystack on the ridge towards Mt. Lafayette. Other locaUties to the 

 south, whence specimens have been brought by our student assistants, 

 who did not determine the position, are, — first, a problematical spot be- 

 tween Mts. Pemigewasset and Kinsman (50); second, on the south-west 

 side of the Mt. Flume ridge, near its foot and just across the valley from 

 Little Coolidge mountain (51); third, on Big Coolidge mountain, three 

 miles north-easterly from Pollard's, or the last house up the East Branch 

 valley in Lincoln (52); fourth, south of Mr. Pollard's, at the south-east 

 extremity of the ridge south-east of Black mountain. Such of these 

 locations as seem certain will be found represented upon the general 

 geological map. 



Nos. 87-95 of Section IX represent what we call the upper member 

 of the Bethlehem group, consisting of dark mica schists, with some 

 gneiss. Its occurrence in other terranes besides that of Bethlehem in- 

 dicates its importance as a stratigraphical member of the gneissic series. 

 I associate it with the Bethlehem rather than with the Lake group for 

 the present, because it is so closely connected with the Bethlehem and 

 Hanover islands of gneiss, but it is very difficult to separate it from the 

 gneiss of Littleton. In Bethlehem and Lisbon this dark schist envelops 

 the south-west extremity of the range, as if it were another protecting 

 envelope. In certain railroad cuts east of Littleton this member is dis- 

 tinctly gneissic, some of the layers being identical with fragments of rock 

 found in Franconia by Prof. J. D. Dana, and thought by him to be very 

 like certain Laurentian rocks in eastern New York (No. IX — 95). In 

 the Ammonoosuc collection this member is represented by Nos. 8, 9, 

 17-22. No. 58 comes from a locality not far south of the Lisbon-Little- 

 ton road-crossing of the Ammonoosuc river, near J. Little's house, and it 

 agrees perfectly with this band of rock, and may be a small island of this 

 schist surrounded by the Lisbon group of the Huronian. 



At the east foot of Eustis hill, and on the Ammonoosuc river at the 

 south line of Littleton, the gneiss is spotted. The same is true of speci- 

 mens in the west part of Bethlehem, upon Section IX. The inversion of 

 the strata at North Lisbon, so as to bring the Helderberg rocks upon 

 both sides, causing newer beds to dip beneath older ones, is illustrated in 

 one of the figures elucidating the structure of the Silurian rocks, in the 

 next chapter. At W. Wallace's in Franconia the gneiss abounds in red 



