198 



GREEN MOUNTAINS IN MASSACHUSETTS. 



bill. Sec sections Q and R'). These relations at the south end of the hill, together 

 with tlic structure of Buxton hill and the northerly pitch observed by Mr. Hobbs al 

 locality 2005, a little west of Buxton hill, lead to the supposition that the quartzite 



of the top of the hill, at the th end. pitches under the limestone at Williamstown. 



The correctness of this conclusion is also rendered probable by the petrographic 

 character of the Stone hill beds, which is similar to that of the Oak hill beds. On 

 the east of Stone hill strata of micaceous feldspathic quartzite occur between those 

 of massive quartzite (locality (IL'Tj. In three localities a flue schist or phyllite of 



footof TaconipRanae roaa 



Observed 15-2030 5S60Wesl 50' 50°North part of 45' Probable Green 



St-ralif? dips E.E E.fjrookE E . StoneMill E Fault, R. 



. lOOOFt 

 700 



500 



1288 



Observed 

 StratifO dips 



EioooFt, 

 700 

 500 

 300 



45°5d3Z42°65 c Probable 

 road EX E E Fault. 



Observed 

 St,racif_ dips 



i 



500 



5ea level 



FIG. 76.— Crns.s-s.-cti.nis s. T, U, Stone Hill. 



inconsiderable thickness appears. Towards the north end of the east side of the 

 hill a blue quartz conglomerate, and a quartzite containing blue quartz ami detrital 

 feldspar occur. 1 .Air. Wolff's descriptions of these rocks are given beyond. 



1 Dewey: "Granitel] of Kirwan, quartz, and feldspar. This aggregate forms extensive strata at 

 tin- cust. base of Stone hill, the feldspar is diffused in grains through the quartz, and sometimes crys- 

 talline, forming porphyritie quartz. This aggregate is often compact and very hard, hut frequently 

 u is porous and hard, forming good millstones. Sometimes the quartz appears in such fragments 

 that the stone resembles breccia." Am. Journal of Science, ser. i. vol. i, 1819, p. 343. 



Sec also Emmons, American Geology, p. 16, on the conglomerate of the granular quartz at Oak hill. 



