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NEW YORK STATE MUSEUM 



along Delaware creek a mile west of Angola and in the escarp- 

 ments on the lake shore, north of the mouth of Mud (or Farn- 

 ham) creek. 



Between the 4 inch sandstone in the escarpment at Angola 

 previously referred to, and the top of the rock exposure at 

 Pontiac there are exposed in the ravine of Big Sister creek 

 about 100 feet of soft, light colored shales in which there are 

 a few black layers, but no flags or sandstones. 



Altogether the beds are much like the Cashaqua beds, except 

 that concretions are much less frequent, and most of them 

 are quite small, but there are many concretionary layers from 

 2 inches to 4 inches thick. 



These beds are also abundantly exposed in the quarries of 

 the Buffalo Sewer Pipe Co., y 2 mile south of Angola, and along 

 the Lake Shore Railroad in the rock cut between the Delaware 

 creek culvert and Farnham. 



A few low escarpments along the lake shore between the 

 mouths of Mud creek and Cattaraugus creek are in the hori- 

 zon of the upper part of the section on Big Sister creek. 



At Pontiac there are two thin beds of light shale in which 

 there are embedded great numbers of small calcareous nodules 

 or concretions that give the beds a pebbly structure. They are 

 separated by 4 feet of light shales, in which the pebbles do not 

 appear. A layer of black slate 2 feet thick is 4 feet above the 

 upper pebbly layer. 



This horizon is exposed in the cliffs on the south side of 

 Cattaraugus creek and a few feet above the water on the south 

 side of the mouth of Silver creek. 



The black layer appears in the bottom and sides of Walnut 

 creek, near the Emke flouring mill in the south part of the 

 village of Silver Creek. 



There is an almost continuous exposure of upper Portage 

 and lower Chemung strata along the channel of Walnut creek 

 for more than 10 miles south from Silver Creek, the first 3 miles 

 in a deep gorge. 



In this ravine next above the 2 foot black layer near the 

 mill, there are 112 feet of shales, nearly all light colored except 

 two dark beds each 11 feet thick. The bottom of the first is 15 



