GEOLOGY OF THE WHITE MOUNTAIN DISTRICT. 1 59 



visited, exhibits planes dipping io° westerly. Though the rock is firmer 

 than ordinary, we have mapped all this region as connected with the 

 Conway division. 



If one takes the short cut to Tamarack pond, from where the old 

 bridle-path leaves the main road for Mt. Lafayette, on the town line be- 

 tween Franconia and Lincoln, on the west side of the valley where he 

 begins to climb, he will find an excellent granite for building purposes, 

 having a lively color, and not liable to crumble. It contains chlorite and 

 the two usual feldspars. A similar rock, but coarser, crops out near the 

 Fish house. At another location on the road-side, a mile or two below 

 the Profile house, there may be seen a crumbling ledge of Conway gran- 

 ite, with both vertical and horizontal joints, and it shows a tendency to 

 decompose along the seams, presenting slightly the aspect of a mass of 

 spherical bodies closely packed together. On the west side of the valley 

 one sees a precipice where the jointed planes are spheroidal, and rudely 

 parallel to the vertical wall of the cliff. At the base of the precipice 

 are large piles of debris. This is on the east wall of Profile mountain, 

 and the southern continuation of the famous Profile. A view of it ap- 

 pears on the same page with the heliotype of Eagle Cliff range from the 

 south. 



Walker's stair-case or falls exhibits finely the jointed planes slightly 

 inclined westerly. [See vol. i, p. 305.] Both the Conway and Albany 

 granites appear on this stream ; but the texture is finer than ordinary, so 

 that it is difificult to draw the line plainly between them. As ledges of 

 porphyritic gneiss occur considerably higher up, it would appear that 

 there existed here a deep valley, into which the granites flowed, not fill- 

 ing up the depression to the brim, unless there have been extensive ero- 

 sions since. 



We find quite near the top of the Lafayette range, close to the porphy- 

 ries, a considerable area of the Albany granite, resting upon porphyritic 

 gneiss or the Franconia breccia. This sheet seems to connect with that 

 already spoken of as underlying Mts. Liberty and Flume. We have not 

 yet found the Conway granite in contact with the Albany north of Mt. 

 Liberty, at the higher level, though there are immense tracts on the 

 western slope of such difficult interpenetration that their exploration has 

 been neglected. The resting of a hornblendic variety of granite upon 



