138 STRATIGRAPIIICAL GEOLOGY. 



hornblende, and other siHceous rocks are cemented together by a hght- 

 colored feldspathic paste. The Conway granite Mes upon it, the lower 

 formation dipping south-westerly. The line of junction is uncommonly 

 distinct, not being so much as a rod away from the Basin itself, which is 

 so much visited by tourists. Hence it is a locality easily reached by all 

 who are interested in determining the relations of the New Hampshire 

 formations to one another. As the breccia is the material which fur- 

 nishes information respecting the age of the formation, this will be a 

 favorable place to commence our inquiry. Although mountains surround 

 this valley upon every side, only a few of their ledges arc represented in 

 the recomposed rock. Neither the Conway nor Albany granite, the por- 

 phyries nor the labradorites of Mts. Lafayette and Profile, appear in the 

 breccia. The Montalban group is not certainly known in the neighbor- 

 hood, so that we should not expect to see its fragments abundant in the 

 mixture, even if it had a prior existence. It is my impression, however, 

 that I have seen genuine Montalban fragments in this rock, and for that 

 reason I placed the Franconia group later in the chronological scale ; but 

 I can now find no specimens among our collections to justify this conclu- 

 sion. The absence of the Pemigewasset series of granites and porphy- 

 ries is of much significance, indicating their appearance upon the surface 

 at a later period. 



This formation ranges from Mt. Haystack in Franconia to Georgianna 

 falls in Lincoln, a distance of over nine miles. Besides the fragmentary 

 character already noticed, it is composed of an indurated schist very 

 similar to the porphyritic gneiss of this neighborhood. Quartz, feldspar, 

 and black mica are usually present, while every exposed ledge has a 

 slightly rusty appearance from the oxidation of iron. Associated with 

 these gneisses are finer-grained granitic layers, which are not of much 

 importance. The ledges at Haystack pond and on the first eminence 

 between Mts. Lafayette and Haystack, as we proceed northerly from the 

 first-named peak, show the common gneissic variety of this formation. 

 Nothing is known of their position in these two localities, but we sup- 

 pose both are united together and to the Eagle Cliff range, which over- 

 looks from the north-east the celebrated Profile of Franconia. 



Travellers from ]3ethlehem and Littleton always notice the irregular 

 ragged cliffs filling up the notch between Mts. Lafayette and Profile, as 



