262 GEOLOGY OF OLD HAMPSHIRE COUNTY, MASS. 



into coarser quartzite, and conglomerate. The argillite is extremely corru- 

 gated and often cleaved, and observations of dip a rod from the contact are 

 of no value in settling a question like this. 



THE WILLIAMS FARM SECTION. THE FOSSILIFEROUS MMESTOKE. 

 PROOF THAT THE WHOLE SERIES IS DEVONIAN. 



The long band of the rocks of the Bernardston series along the lower 

 slope of West Mountain has been brought into its present position by 

 extensive dislocations, and is plainly cut off by two transverse faults which 

 run approximately in the bi'ook gorge north of the limestone and in the 

 larger gorge of Fox's brook half a mile south. The area between, contain- 

 ing the fossiliferous limestone, is the one here described. (See PI. IV and 



%■ 15.) _ 



Passing up the hillside back of Mr. Williams's barn, the first bed and 

 the upper one on the section (fig. 16, p. 264) is a dark muscovite-schist (1), 

 which is exposed in a single small quarry and separated by a depression 

 which runs with the strike, and which I have assumed in the section to be 

 occupied by the same schists and to have been formed by their erosion. 

 The outcrops are almost continuous across the quartzite (2) and the lime- 

 stone (4) which follows to the second outcrop of schist, where a similar 

 depression separates the latter from the second band of quartzite, which I 

 have in like manner supposed to be occupied by this schist. 



Section of the Williams farm rocks. 



Feet. 



1. Garnetiferous mica-schist 73 



2. Micaceous quartzite and coDglomerate 443 



3. Magnetite, maximum 3J 



4. Limestone 19^ 



Quartzite concealed beneath the limestone ( ?). 



Fault. 



1'. Mica-schist 115 



2'. Quartzite and conglomerate, if conformable with the mica- 

 schist 656 



Argillite. 



(The beds below the fault are a repetition of those above.) 



The argillite (fig. 16, west end). — Beginning nearly a mile northwest 

 of the Williams house, and just north of the point where the road over West 

 Mountain bends sharply west, a long ridge of the typical, excessively con- 



