CHAPTER V. 



THE GNEISSIC AREA FROM LANDAFF TO THE SOUTHERN BOUNDARY OF 



THE STATE. 



BY J. H. HUNTINGTON. 



IJOiHIS area embraces the entire western part of the Merrimack Valley 

 J% district, and its western limit corresponds with that of the dry land 

 in the Labrador period, as marked on a map in Volume I, opposite page 

 528. The rocks that bound it on the west are the quartzites and mica 

 schists of the Coos group. On the east the limit is generally the por- 

 phyritic gneiss, except towards the south, where it embraces the whole 

 of Cheshire county. The line that bounds the area on the west runs 

 nearly parallel with the Connecticut river ; that on the east is not so 

 direct, yet it has the same general direction as that on the west. 



Along the western border, at intervals where the newer rocks are 

 included in this district, there are mountains of considerable elevations, 

 as in Orford, Dorchester, and Grantham. Elsewhere the country is high 

 above the sea-level, and rises in hills of varying height. East of this 

 the common gneiss forms the central part of the area, and in places 

 extends to the western border, the country nowhere rising into hills of 

 very great height ; but in parts of Warren, Wentworth, and Dorchester 

 the country is generally high, while in the eastern part of Unity and in 

 Lempster, it forms an elevated plateau-like area. East of the common 

 gneiss, a fine-grained gneiss, — forming a transition state into mica schist. 



