LOWER SILURIAN SYSTEM OF EASTERN MONTGOMERY CO. 443 



on arenaceous rock (Calciferous) which forms the floor of the 

 quarry at that point. Apparently the Birdseye limestone has thinned 

 out entirely in a distance of two rods. In the western part of the 

 quarry the Calciferous is not reached and the lowest layers exposed 

 have, the characters of Birdseye though there is here no sharp line 

 between the Birdseye and Black river limestones. In the central 

 part of the quarry there are apparently from 7 to 9 feet 

 through which the Columnaria alveolata ranges. The 

 rock at this point is compact and thick bedded. In the western part 

 of the quarry the same layers are coarser grained and even more 

 massive. In fact they resemble the lower massive member of the 

 Trenton substage in lithologic characters, but their fauna as will be 

 seen from the above list is characteristically Black river. No. 8 as 

 seen in the western part of the quarry presents most peculiar 

 characters. Portions of it are almost entirely made up of fragments 

 and pebbles of brownish arenaceous rock quite similar to the Cal- 

 ciferous sandrock. The matrix is somewhat crystalHne and contains 

 a few small specimens of Columnaria alveolata which 

 from their general appearance and association may be regarded as 

 derived from the subjacent Black river beds in a manner similar to 

 that in which the arenaceous pebbles were derived from the Cal- 

 ciferous sandrock. In some parts of the quarry, specially the 

 southern part^ the Black river limestone contains an abundance of 

 iron pyrites and in some cases pockets lined with crystals of calcite. 

 The upper surface of the rock at this point is striated, the striae 

 running N 85° W. The dip of the strata in this quarry is about 

 2j° S, 20° W. Vanuxem mentions pebbles similar to the ones 

 occurring in this quarry, at Tribeshill and about Amsterdam.^ 



The Trenton limestones are exposed at several points between 

 Quarry hill and Mannys Corners, and both north and south of the 

 highway one half mile east of Mannys Comers are small quarries in 

 the Black river and Birdseye beds. In the exposure south of the 

 highway are 8 feet of dark lumpy limestone and i foot of 

 compact fine grained Hmestone at the base. North of the highway 

 the Birdseye Hmestone is exposed and contains excellent examples 

 of Phytopsis tubulosa Hall, with the surface reticula- 

 tion mentioned by Emmons (pt 2, p. no). 



Between Quarry hill and Van Epp's hill (the high hill just north- 



^Geology of New York, pt 3, p. 44. 



