APPENDIX A. 



STONE HILL, NEAR WILLIAMSTOWN. 



This oft-studied and problematic locality lias not yielded anything' very remark- 

 able. 1 Observations of strike and dip were made, typical rock specimens were col- 

 lected and submitted to Mr. Wolff for microscopic examination. Three cross sections 

 have been constructed, S, T, I t (Pig. 76), and one longitudinal oue, R' (PL xxin). The 

 difficulties at Stone hill arise from the small number of outcrops and their entire 

 absence at critical points. 



The areal geology of the hill is indicated on the geologic map. The first question 

 which arises is whether the mass of quartzite along the east side of West brook val- 

 ley, apparently overlying the limestone, forms a part of the quartzite at the top of 

 the hill. There is a gentle slope of arable land between the two, and ;i small lime- 

 stone outcrop on the east side, at the north end of the westerly mass, has a foliation 

 which strikes with the trend of this strip of cultivated laud. It has therefore been 

 conjectured that the two masses are separated by limestone, but the other supposition 

 would be tenable. 



The dips in the main mass of quartzite, on both sides and in the center, are 

 easterly; but at the south end the dip (pitch ?) is south, and a well marked southerly 

 pitch occurs in the quartzose limestone at the southwest end of the hill (localities 

 1103-1105). A very high southerly pitch occurs also in the limestone a little, farther 

 south (locality 62) on the north side of the Green river bridge crossed by the road from 

 Sweefs corners to South Williamstown. Here there is a small, sharp anticline with 

 an almost vertical pitch. A southerly pitch occurs again in the schists at the 

 north end of Deer hill. High upon the southeast side of Stone hill (locality 1106) 

 an outcrop of quartzite with limestone north of it shows a southeast pitch. This, 

 however, has been regarded as a quartzose part of the limesti me, Formation €Ss. From 

 all these facts the quartzite at the top of the south end of Stone hill appears to pitch 

 under the limestone farther south and down the hill, and that limestone to pitch 

 under the Berkshire schist of Deer hill. We thus have here in their normal succes- 

 sion, the Vermont formation, the Stockbridge limestone, and the Berkshire schist, 

 and the relations which seem to exist between Clarksburg mountain (Oak hill) and 

 the north end of the Greylock mass are repeated here between Stone hill and Deer 



1 See Emmons: Geology of the Second District of New York, pp. 1 r>. 156, L59; Report on agricul- 

 ture pp. 83-86. James D. Dana: Taconic rocks and stratigraphy, p. 106; Geology of Vermont and 

 Berkshire, p. 206. 



