54 



STRATIGRAPinCAL GEOLOGY. 



rock in Errol is entirely mica schist, often containing garnets, and the 

 strata everywhere are nearly vertical. The mica schist extends into 

 Millsfield, but east of Millsfield ponds there is a band of schist that prob- 

 ably belongs to a newer group. This is perhaps half a mile in width. 

 West of the ponds the mica schist again outcrops ; and the dip varies 

 greatly as we approach the granite in the west part 

 i! of the township. The mica schist of the character 

 % just mentioned does not extend south of Millsfield in 

 I this section of the state. 



J HuRONiAN IN Vermont. 



I Directly south of North Stratford, on the west of 



•3 ^ the Connecticut, the rocks consist of dark siliceous 

 J ^ schist, that sometimes contains crystals of a rare va- 

 I ■; riety of andalusite. Through Maidstone, along the 

 ^ 2 Connecticut and southward to Waterford, we find the 

 "c § same rock as that described as occurring in North- 



'■s umbcrland and Lancaster. West of this rock, in 



.'i a Guildhall, we find the gray siliceous schists that 

 i; -5 



1 jS extend southward through Lunenburg, and they ter- 



"S g minate in Concord. 



M 3 



I ^ Atlantic Series. 



I -^ We give here the outline of the Atlantic series. 

 f The rocks belong chiefly to the Montalban group, 

 I While these rocks are developed very extensively in 

 I New Hampshire, they occupy a very large area in 

 = Maine and a small but important area in Vermont. 

 i For the area in Maine, the reader is referred to the 

 "5 preceding chapter. In New Hampshire its most 

 ^ northern outcrop is at the southern extremity of 

 Umbagog lake, where the rock is a gray micaceous gneiss and horn- 

 blende schist. It extends southward through the east part of Cam- 

 bridge. In Success the Montalban group gradually extends eastward. 

 Southward, the rocks in the whole area of the towns of Shelburne and 

 Gorham, except in the north-west corner of the latter, arc Montalban. 



