86 NEW YORK STATE MUSEUM 



Associations of the red slates. Along- both the north and 

 south roads from Pleasant Valley to Moores A-Iill the red slates 

 occur just to the west of small conglomeratic limestone patches that 

 have plainly been brought up by faulting. There is no way of de- 

 termining the amount of displacement, but it is reasonably clear 

 that the red slates lie above the limestone and are younger and 

 probably are not far from the base of the slate formation. 



Along the New York Central tracks near Fishkill Landing sta- 

 tion are heavy-bedded members of the slate formation, such as 

 make up most of it northwest of the Wappinger creek limestone 

 belt. Assuming that the slates west of the Glenham gneiss belt 

 have synclinal structure, these heavy members can not be far from 

 the axis of the fold and lie several hundred feet above the red 

 slates in stratigraphic position. The reason for the gneiss being in 

 contact with, or in proximity to, the red slates along the Glenham 

 belt, while the limestone conglomerate has that position at the north, 

 is clearly due to greater vertical movement of the older rocks at 

 the south and west. 



The red slates have not been noted within this quadrangle north- 

 west of the Wappinger creek belt. According to the writer's ob- 

 servations, the companion members of the red slates southwest of 

 that belt, although sometimes showing heavy beds and even fine con- 

 glomerates like those seen at the northwest, are prevailingly mere 

 fissile and splintery mud rocks of blackish-gray color. These also 

 occur along the northwestern margin of the Wappinger belt, but 

 farther northwest give way to beds of coarser sediments. 



Quartzite near Rochdale. Along the road from Manchester 

 Bridge to Pleasant A'alley, east of M^appinger creek, between the 

 farm of A. W. Sleight and that of George E. Smith at Rochdale, 

 are prominent ledges of compact quartzite which rather strongly 

 resembles some varieties of the basal quartzite. These ledges are 

 portions of a continuous strip which can be traced from a ledge on 

 the farm of A. W. Sleight just north of the Overlook road north- 

 ward, roughly parallel with the Pleasant Valley road, to George 

 E. Smith's house. Just south of here it crosses the road and ends 

 at the bank of the creek west of the house. East of the road it 

 ends just beyond the barn south of the brook shown on the map, 

 which apparently occupies a fault between the quartzite and the 

 slates to the north of it. This quartzite is bounded entirely by the 

 slates, except where it disappears in the creek. Here it is only a 

 short distance from the Trenton limestone at Rochdale. Along the 



