GEOLOGY OF THE WHITE MOUNTAIN DISTRICT. 1/5 



at the Notch at the junction. Half a mile to the north they hold essen- 

 tially the same position, all of them dipping 50° N. 38° E., but are very 

 evenly bedded with the mica in layers, and are not permeated with the 

 intense hardness that prevails below. 



The character of the rocks upon the top and west side of Mt. Webster 

 may be seen to good advantage from the summit of Mt. Willey, across 

 the valley, because they are of different colors. The upper part is a 

 reddish-brown color, corresponding to the ferruginous Montalban schists. 

 These extend plainly from above the large cliff just described to a point 

 opposite the Willey house, where the gray color, indicating the occur- 

 rence of the Conway granite, takes its place. The upper rock is trav- 

 ersed by thirteen large granite veins, broadest at the lower edge of the 

 reddish rock, and ramifying into numerous branches above. Some of 

 them are tortuous, with an average direction parallel to the junction be- 

 tween the red and gray ledges. I have not been able to traverse exten- 

 sively the granitic slope beneath, but have thus far seen there only the 

 coarser Conway granite, occupying fully seven eighths of the surface. 

 In several places patches of the reddish color flow down into the gray, 

 sometimes irregularly. This is the result of aqueous action, and there is 

 no reason to believe the rocks have been much dislocated by faulting. 

 There are fourteen slides on the west side of Mt. Webster. From Willey 

 one sees also the pyramidal shape of Mt. Webster, as expressed on our 

 contour map. Visitors travelling along the valley beneath are led to 

 believe that the top is nearly horizontal. The highest point is at its 

 northern extremity. 



We conclude that the line of union between the Montalban schists and 

 Conway granite is in general straight, but when minutely investigated, 

 jagged like a comb wanting occasional teeth. From this frayed edge 

 innumerable large segregated granite veins spread off into the schists 

 like a long row of immense branches of trees, mostly in their natural 

 vertical position. 



Mt. Willey range of Slate. Our researches lead us to believe that this 

 rock has its southern termination near the summit of Mt. Willey, being 

 as wide as the peak at the depth of a thousand feet, say a mile and a half. 

 The dip on the summit is 80° W., and perhaps on the south side, near 

 their base, the slates may dip easterly at a somewhat smaller angle. On 



