THE GEOLOGY OF MOUNT KEARSARGE 



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groundmass of the granite-porphyry consists of a fine granular 

 mixture of reddish feldspar, smoky quartz, and black mica, 

 together with, in some places, fine black hornblende and a little 

 magnetite. Iron pyrites is occasionally seen. 



The granite-porphyry does not weather and crumble so rapidly 

 as does the Conway granite; neither does it form any such 



Fig. I. — Just left of the center of the picture is shown an inclusion of finely- 

 grained gray granite in the coarse Conway granite. Inclusion 3-4 feet in diameter. 



gravelly debris. It is but a few feet, fifty or so, in thickness on 

 the south side of Kearsarge, and on some sides of the mountain 

 was not observed at all, either because entirely absent or because 

 covered. There is a like granite-porphyry in the bed of Cedar 

 brook on the north side of Moat mountain, where there is exposed 

 an excellent section. 



Above this granite-porphyry in Mount Kearsarge, or above 

 the Conway granite where the porphyry does not occur, the rock 

 is a quartz-porphyry. This latter rock varies in color from a 



