FIFTH REPORT OF THE DIRECTOR 1908 



17 



it. In two old, abandoned quarries on the farm of Mr Byer, near 

 Manchester Bridge, 3 miles east of Poughkeepsie, the Trenton 

 conglomerate, so well displayed at Pleasant Valley and Rockdale, 

 was found filled with Solenopora com pacta and crinoid 

 stems, and overlain by hard, blue, medium bedded limestones carry- 

 ing a rather full assemblage of brachiopods, with an occasional 

 trilobite, all of apparent Trenton affinities. Southeast of Pough- 

 keepsie on the Spackenkill road, on the farm of Mr Ruppert, in a 

 quarry being worked for lime, in a hard, thick-bedded limestone, 

 coils resembling gastropods and a Hyolithellus were discovered and 

 above these in the somewhat thinner beds in the upper part of the 

 quarry, Lingulepis pinniformis and a trilobite probably 

 Ptvchoparia, thus confirming the occurrence and abundance of the 

 Potsdam fauna as first discovered by Dwight nearer Poughkeepsie, 

 2 miles north of this quarry. The now known localities of Pots- 

 dam fossils within this quadrangle and the thickness of the strata 

 show it to be a prominently developed terrane. 



Numerous smaller patches of limestone, or limestone conglomer- 

 ate, occurring as inliers in the slates to the east of Wappinger creek 

 have been noted and mapped, but can not be discussed here and may 

 be left for the fuller report. 



Slates. The Paleozoic rocks of this quadrangle present a com- 

 plicated structural and straligraphic problem. The structural 

 feature^ and many details can not be more than alluded to in this 

 report. 



Recalling the faulted proximity which Lower Cambric rocks 

 have to those of Ordovicic age at the north, as at Bald mountain, 

 Washington co., the slates and schists in the eastern part of the 

 quadrangle were studied for such relationships. The small lime- 

 stone inliers were examined in this connection. The possibility 

 of the Xormanskill and the Utica occurring in the western slates 

 was considered; but no evidence of any of these was secured. 

 Fossils were hard to find. In the slates they were noted at many of 

 the localities where previously discovered, but were not seen at 

 others. The general relationships suggested nothing older than the 

 Trenton limestone of the region. Only one new fossil locality was 

 discovered in the slates. At Swartoutville, 2 miles north of 

 Brinckerhoff, between Fishkill Village and Hopewell Junction in 

 fissile, broken slates, along a fault between them and the barren 

 northwest margin of the Fishkill limestone, brachiopod fragments 

 were discovered. Their examination has only suggested a horizon 

 of Trenton or later age. 



