e 4 PHYSICAL GEOGRAPHY. 



tables from Mt. Washington and Hanover ; and a sketch of the geology 

 of southern New Hampshire. The map illustrating it shows the follow 

 ing formations between the Exeter sicnites and the Coos group, along 

 Connecticut river, given in the supposed order of their age: 



1. Porphyritic gneiss and granite. 



2. Granitic gneiss. 



3. White Mountain series, including andalusite gneiss, ordinary and 

 imperfect gneiss, the so-called granite of Concord and Fitzwilliam, beds 

 of soapstone and limestone. 



4. Bands of quartzite. 



5. Mica schist. 



6. Andalusite slates or outliers of the Coos group. Of these the map 

 distinguishes the porphyritic group, the quartzite bands, the mica schist, 

 and the Coos outlier. The other gneiss, being yet known imperfectly, I 

 will not attempt to divide. 



The following remarks concerning the second group may be quoted, 

 as this had not been distinguished from the adjacent groups before. 



There is decided evidence of a range of very ancient gneiss from Mason to Deerfield. 

 It abounds in feldspar; the strata are very highly inclined and remarkably plicated. 

 It is very granitic, so much so that but a slight additional metamorphic action would 

 be needed to obliterate all the planes of stratification. This formation is probably 

 repeated west of the quartzite ranges, and also in Cheshire and Sullivan counties. 

 The character of the strata, and the superabundance of feldspar, readily distinguishes 

 it from everything else. 



Also, a few words about the &quot;Concord granite,&quot; and the &quot;mica schist&quot; 

 of Rockingham county. 



The &quot;Concord granite&quot; has been traced irregularly from Concord to Fitzwilliam. 

 It will require more detailed examinations to enable us to say positively where this 

 valuable band may be found. It seems to lie near the quartzite, say from a quarter to 

 half a mile above it. Hence, if it exists as a range, it should be adjacent to all the 

 quartzite bands, and its distribution can be determined readily in the manner suggested 

 above. A section across these ranges near Manchester shows a similar granite inside 

 both of them, while a protracted examination has failed to show the quartzite beyond 

 the west part of Concord. This rock is not a proper granite. There is an arrangement 

 of the particles of mica along parallel planes, which allows the rock to split readily. 

 These we regard as strata. They are seen plainly in the inferior qualities of the stone, 

 and farther south the celebrated &quot;granite&quot; of Pelham and Monson, Mass., shows the 



