• 168 [Assembly 



rocks the bounding line between them and the qnartzite beds on the 

 south-west and west follows a quite marked hollow in the surface first 

 in a north-west and then in a more northerl}^ direction to Miller pond. 

 This depression is, in places, a few rods only in width, bordered on the 

 one side by the gneiss, and on the other by the quartzite. Miller pond 

 occupies the dej^ression between the mountain and the blue limestone 

 and slate hills. North of it the quartzite was not observed, the ad- 

 jacent formation being blue limestone near the pond and slate to the 

 north. The outcrops of the limestone are comparatively small ; the 

 slate forms a bold and rocky ridge on the west and north-west of the 

 Little Stissing part of the range. From Miller pond to the north end 

 of the mountain the limit of the gneissic outcrop may be said to be 

 about three-quarters of a mile east of the main road from Old Attle- 

 bury to Mount Eoss. At the north there is a rather deep depression 

 between the two formations and it is traceable around to the north- 

 east end of the gneiss. A wood road folloAvs it for some distance north 

 from the gap, east of the Simmons farm-house. Excepting near Mil- 

 ler pond the newer formations of slate and limestone are not seen on 

 this western side of the mountain close enough to the gneisses to en- 

 able us to make out their relative position. South of the Simmons 

 place and north of Miller pond there is a narrow outcrop of the blue 

 limestone whose beds dip steepl}^ to the north-west and within sixty 

 feet of gneissic strata, having a steep dip also, but more to the west- 

 north-west. Nearer the pond and to the south of this locality the 

 blue limestone forms low ridges at the foot of the mountain and all 

 the strata stand nearly on edge, dipping in a general north-west direc- 

 tion . A more interesting locality, and where there is an approximation 

 to contact phenomena, is a half a mile south of Miller pond. At this 

 place the gneiss (a feldspathic variety) crops out within ten feet of the 

 grey quartzite and conglomerate. The dip of the former is 80° north 

 80° west (mag.) and that of the latter is the same, showing conforma- 

 bility. But one mile to the south and near the south end of the 

 mountain the quartzitic rocks and the siliceous conglomerate crop out 

 near the gneiss and their beds dip only about 10° westerly, whereas 

 the gneiss stands vertically and with a nearly due north strike. The 

 quartzite outcrop on the south-east and toward Stissing Junction is 

 marked by a more nearly horizontal position of its beds. The quart- 

 zite outcrops on the east, near J. A. Thompson's place, have a gentle 

 west-north-west dip, the strata passing under a blue limestone and a 

 red shaly rock lying between them and the gneiss of the mountain 

 slope. The observed phenomena of the closer outcrops of gneiss and 

 these limestones and quartzites appear to prove a want of conforma- 

 bility between them. 



From the observations made of dips near the foot of the mountain 

 and on three cross-section lines, the inference is drawn that there are 

 close folds whose axes have a general north-east and south-west direc- 

 tion, and are oblique to the trend of the mountain. The northern 

 point of one of these anticlinal folds was seen one-quarter of a mile 

 south-south-west of J. A. Thompson's residence, and at the eastern 

 base of the mountain. The pitch or angle of inclination was 40° to 

 the north-east, or a little north of north-east. The observed dips 

 ranged from 50° to the east-south-east to 80° north 80' west. In 

 Little Stissing the structure, as indicated by the dips observed, is 



