GEOLOGY OF THE POUGHKEEPSIE QUADRANGLE 53 



a strike of n. 23° e. and a dip of 70° s. e. This may belong with the 

 slate formation and may therefore be on the downthrow side (let- 

 tered F, %. 18). 



Ledges of rock similar to that in Riippert's quarry occur to the 

 southeast along the western margin of the belt, to the north and 

 south of the first road leading to the river, and west of the road 

 leading from this toward Camelot station. East of Camelot sta- 

 tion, about 100 feet up the hill, on the south side of the New 

 Hamburg road, ledges of rock identical with that in Ruppert's 

 quarry strike approximately east and west and dip about 12° to 

 the south. 



The first road leading to the river, south of the Spackenkill road, 

 leaves the Poughkeepsie road (old Albany turnpike) one-fourth 

 mile south of the schoolhouse. The river road gives off two 

 branches, the shorter, lower one going to the dock of the White- 

 head Sand Company and the other to Camelot station. 



On the east side of the lower road, just north of the red house, 

 coarse conglomerate, familiar in Trenton localities within this quad- 

 rangle, outcrops in one or two large ledges. This rock, in a brec- 

 ciated condition, was also noted farther south along 'the upper road 

 where this runs parallel with the railway track, about one-fourth 

 mile north of Camelot station. 



Along the middle portion of this western strip the topography 

 generally indicates a very gently sloping almost flat substratum of 

 rock, and the extraordinary width of the belt is plainly due to the 

 nearly horizontal position of the underlying strata for long distances. 



The varieties of rock described by Professor Dwight would 

 seem to be accounted for mainly as outcrops across the dip of several 

 beds showing variations of texture and composition, and partly to 

 the different effects of weathering on these, as well as to possible 

 frictional brecciation. 



The portion of the section 

 which may be seen at Stoneco 

 in the quarry of the Clinton 

 Point Stone Company is be- 

 tween one-fourth and one- 

 third of the breadth of the 

 strip from its eastern margin 

 and displays a thick mass of dolomitic limestone dipping gently to 

 the west (see plate 8). For the most part it is thick-bedded. There 

 are some thinner layers near the top and in the middle. Some beds 

 carry numerous chertlike masses and in this particular, as well as in 



Fig. 19 Section at Stoneco quarry 



