GEOLOGY OF THE WHITE MOUNTAIN DISTRICT. 1 7/ 



In illustration of a change in the direction of the slate range near the 

 railroad, I will first call attention to the small heliotype of Mt. Willard, 

 colored to represent the several formations. It was taken from the Wihey 

 slide. The house in the foreground very nearly obscures from view the 

 original edifice occupied by the unfortunate family at the time of their 

 engulfment by the sliding granite debris. Its front barely appears un- 

 der the eaves of the addition. The blue color represents the area occu- 

 pied by the slate just described, bounded by the Conway granite on the 

 south, with an intervening belt of the spotted variety on the north. This 

 last will be seen to extend to the top of Mt. Willard, and also to appar- 

 ently cap the slate nearly over the house. That distant mountain, 

 however, is the north spur of Mt. Field, a remarkably conspicuous 

 eminence, as seen from the Crawford house. The spotted rock is con- 

 tinuous from near the railroad. While it may not exceed a score of feet 

 at the base of the precipice, it is two hundred feet wide on top of Wil- 

 lard, and as much as a mile on the spur of Field. Its course is the same 

 with that of the slate area, or N. ^jf W. The principal part of the steep 

 south side of Mt. Willard is the Conway granite, of which nearly 1200 

 feet altitude are visible. It constitutes only the south face of the moun- 

 tain, whose principal mass is composed of Montalban schists, which are 

 shown by color on the extreme right. The schists support the granite 

 behind, the line of junction being vertical and transversely across the 

 strata. The granite is supposed to follow the other variety north-west- 

 erly, to where it is extensively developed on Cascade brook and the east 

 flank of Mt. Tom. The strike of the slate does not agree entirely with 

 that of the area occupied by it. Very near the junction on top of Willard 

 we have the strike N. 22° W., and N. 12° W., a little beyond, while the 

 course of the area is N. ']'j° W. Following down the junction to the 

 railroad from the top, I found quite near the top the strike N. 8° E., and 

 a westerly dip. Lower down is an anticlinal, very near the border, but 

 it is only a few rods wide. About one or two feet thickness of the slaty 

 mass next the junction consists of a breccia not unlike that on Mt. Pe- 

 quawket, usually more compact. The granite close by the junction has 

 its orthoclase and quartz in distinct crystals, whose faces show distinctly 

 when the rock is broken, making beautiful specimens for the museum 

 shelves. A few feet away they lose their perfect character. About half 

 VOL. II. 23 



