WAMSUTTA GROUP. 153 



spur of the railroad into the trap locality would necessitate building a 

 bridge or trestle across Abbots Run From a point half a mile north of 

 the station, it would require about 4,000 feet of track to reach the ledge. 



Quartz-porphyries, felsxtes, and granophyres Intimately aSSOCiated witll tllC red 



rocks of the Wamsutta group is a series of acid igneous rocks of felsitic and 

 granophyric structure, the distribution of which is parallel with that of the 

 diabase dikes just described, and, like the former, these rocks occur in knobs, 

 whether true bosses or faulted and disjointed dike-like masses being not 

 easily determined. In general they are limited to the horseshoe fold, and 

 do not accompany the Wamsutta group eastward along the northern 







Fig 14 —Section through felsite knob in Attleboro Massachasetta (See table below ) 



margin of the basin nor in the Norfolk County Basin beyond the narrows 

 in Wrenthara. The felsites are usually of a reddish colon 



A ci'oss section (fig. 14) of one of these knobs south of Reservoir Pond 

 illustrates the general character of the association with the Wamsutta group. 



The succession, beginning on the east, is: 



Section south of Reservoir Fond. 



Peet 



Sandstone (red, pebbly) and shale (red) 40 



Diabase ' 40 



Felsite 10 



Conglomerate, red 8 



Felsite, in large knob 50 



(Western contact not seen.) 



