TYPICAL FOSSILIFEROUS AREA 465 



the sandstone (ss) and the addition of a synclinal of slates at the eastern 

 base of the hill. 



The Blueberry Mountain range extends from Fitch hill southerly 

 through Littleton, Lisbon, Lyman, and Bath and is a mass of argillite 

 with a synclinal structure throughout. A typical section, figure 4, 

 plate 42, is that from the slate quarry across to the Ammonoosuc, about 

 2 miles southerly from the fossils in the Fitch pasture. It shows the 

 fossiliferous limestones at the base on both sides (LL) overlain by sand- 

 stone and conglomerate (CO) and two kinds of slate, the lowermost (/)) 

 being very black and the other (E) drab, with a total thickness esti- 

 mated to be 1,500 feet. Layers of grit alternate with some of the slates. 

 The basal parts of the argillite carry a coarse conglomerate to be de- 

 scribed later. 



Taking the Blueberry Mountain range as a whole, it may be said to 

 commence in Bath, has been cut deeply in Lyman by Smith brook and 

 Mill brook, and shows a more decided gap just north of Fitch hill, having 

 been eroded by a branch of Parker brook, which has removed nearly all 

 the slate. Considered as a continuous elevation, the range should con- 

 nect with the Dalton mountain, but deep erosions on both sides of Manns 

 hill exhibit other rocks than slate. The topography of the northeastern 

 part of the range is shown on the Whitefield quadrangle of the United 

 States Geological Survey. 



The fossils characterize only the basal limestones, which are middle 

 Upper Silurian. There is certainly enough thickness of strata in the 

 sandstone, slates, and conglomerate superposed on the limestones to 

 suggest at least the residue of the Upper Silurian, and perhaps the 

 Devonian. Rocks of similar petrographic character may be followed 

 down the Connecticut valley into Massachusetts (including Bernards- 

 ton), a distance of 150 miles, where Devonian fossils have been recog- 

 nized. Fossils of this age adjoining lake Memphremagog have been 

 mentioned above, 60 miles distant, but in a parallel basin. That hori- 

 zon is higher than anything known in northern New Hampshire or 

 Vermont. 



Igneous Ejections 



Omitting for the present the description of a complex series of schists 

 adjoining the Blueberry synclinal, reference must be made to a different 

 class of rocks. It may be truthfully said that this synclinal in Littleton 

 rests on igneous materials. Below and in contact with the fossils on 

 Fitch hill the rock is a chloritic foliated granite (protogene of Hawes). 

 Above the fossils it is a coarse diorite which has converted the slate into 

 hornfels. Along the east base of Blueberry mountain are lenses of horn- 



