Prosper and Cumings-^Lower Silurian Sections. 657 



B 2 . Above the cut and through the fields to an old quarry, are i3 ^i et m 

 numerous exposures of massive arenaceous limestone having, especially in the 

 lower layers, fucoidal markings. Fucoidal member of the Calciferous. 



B :i . About one-half mile southwest of Pattersonville, and at the 7 F ^ m 

 head of a small run, is a small quarry to the south of an old limekiln. The 

 Calciferous is exposed in thin layers at the bottom of the quarry in the run, 

 and resting upon it is a layer about a foot in thickness, of bluish-drab tine 

 grained limestone which w eathers ash grey. The outlines of several fossils 

 are shown on the surface of this layer, and notably that of the cephalic shield 

 of a large trilobite (Asaphus platycq>halusf). Above this are exposed about 

 five feet of thin, bluish-black, fine grained, irregular, lumpy layers, weathering 

 light ash-grey and abounding in fine specimens of CoVwmnaria alveolata, 

 Goldfuss. In the east side of the quarry the rock is exposed in thicker 

 layers, the lower containing Columnaria. Just over the fence to the 

 east is a larger quarry in which the upper layers of the former quarry are 

 exposed and contain large masses of Cohtinnavia alveolata in the same strati- 

 graphic position. In this quarry the light- weathering layers are capped l>v 

 dark-weathering, crystalline layers. Black river limestone. 



B 4 . A short distance south of the exposures of No. 3 is an s v ^% 

 extensive quarry, the western end of which is known as the Walker quarry, 

 and the eastern end as the Moore quarry.* The lowest rock exposed in these 

 quarries is dark, bluish-grey, crystalline limestone, massive and weathers 

 bluish-grey. Highly fossiliferous. Heavy bedded member of the Trenton. 



B 5 . Resting on the massive layers are thin, irregular dark blue layers 

 of fine-grained limestone with intercalated black carbonaceous shale. Highly 

 fossiliferous ; especially rich in brachiopoda. 



B % . Covered from top of limestone in the quarry to lowest r/'Jl^ 

 exposure of shale in an open drain south of the quarry. 



B 7 . Black, argillaceous shale to the top of the hill. Utica slate. 327 F = e 5T5 



The above section is of interest on account of the excellent exposure of 

 the fossiliferous Trenton and Black river limestones, and from the fact that 

 it affords an opportunity for determining the south dip by comparison with 

 the exposures across the river exactly one mile to the north. The base of the 

 Trenton limestone on the north side of the river is approximately 590 feet 

 A. T., and on the south side 450 feet, giving a southerly dip of 140 feel 

 per mile. 



* Bulletin New York State Museum, No. 3, 1888, p. 105. 



42 



