320 



Report of the State Geologist. 



rods from the road. Between here and rhe county line, I was unable to 

 find any further exposure of this limestone. 



Just south of the Erie railroad tracks, a mile east of Alden, is a good 

 exposure of the Moscow shale with a fauna like that found near the Encrinal 

 limestone at all points west ; and in the absence of evidence to the contrary it 

 is assumed that this limestone crosses the county line near the New York, 

 Lake Erie and Western railroad. If so, the Hamilton must be thinner here 

 than it is east or west of Alden. The Genesee slates in Erie county belong 

 mainly to the part lying above the Styliola band, as already shown. 



The Portage Group. 



The Portage rocks crop out south of the foregoing, to the county line, no 

 area of distinctly characterized Chemung strata having been observed by me 

 within the county. The lower part consists of alternations of olive-green 

 with bituminous black shales, including, rarely, a thin layer of argillaceous 

 sandstone. Above these, the rocks become more arenaceous, passing somewhat 

 abruptly into a series of shales alternating with argillaceous sandstones of 

 varying thickness which furnish stone of considerable economic importance. 

 The boundary between the upper and lower beds is therefore indistinct. North 

 of a line connecting Wales Centre, East Aurora, North Boston and North 

 Collins, no sandstone of consequence has been noticed, and none has been 

 seen west of the Buffalo and Southwestern railroad, between the latter place 

 and Gowanda. The streams flowing across the lower Portage outcrop have 

 cut deep gorges with precipitous sides, but are almost destitute of waterfalls. 

 The black shales contain many calcareous septaria, usually lenticular and of 

 enormous size. Specimens six feet in diameter are comparatively common, 

 and one measured nine feet in diameter by five feet in thickness. 



The gorge of Eighteen Mile creek above North Evans, and of Cazenovia 

 creek below East Aurora, show good lower Portage sections and furnish 

 excellent specimens of septaria. The southern part of the county is covered 

 with drift, which in some places is 500 feet or more in thickness. This has 

 hidden the rock and broken the continuity of observations, so that complete 

 sections of the Portage rocks like those made in Livingston and Wyoming 

 counties have not been achieved. The valley of Buffalo creek, above Wales 

 ( Vntre, shows heavy sandstones and Hags as far south as the town line between 

 Wales and Holland. 



Stone is quarried on the Joseph Myers farm, two miles east of Wales 

 Centre, and also on the Ulrich farm on the Centre Line road, about one ami 



