62 GEOLOGY OF ERIE COUNTY 



lower beds and their contact with the Dunkirk shale are shown 

 in Big Indian creek. A small gully opening into Cazenovia 

 creek from the west at Glenwood shows about two hundred feet 

 of Gardeau. The upper beds are seen in the numerous gullies 

 opening into the east branch of Cazenovia creek from the east, 

 between Blakely and Holland, and in the gullies opening into 

 Buffalo creek between Wales and Java. Johnson's Falls just 

 outside of Erie county, north of Strykersville, is in upper Gardeau 

 and Laona sandstone. The fall, which is about 45 feet high, is 

 capped by a layer of hard, compact, blue sandstone five feet thick, 

 below which are gray shales showing cleavage planes, thin layers 

 of black shale with cleavage planes, gray shale with nodules, and 

 thin sandstone layers. In the face of the fall there are five of 

 these sandstone ledges from a foot to three feet thick: 



The Gardeau shales are moderately fossiliferous. Some of 

 the sandstone layers near the top contain sponges. Luther 

 reported finding "the common Portage fossils in small numbers" 

 at Johnson's Falls, and further says that crinoids and aulopora 

 also occur. He further reports that at Brocton cephalopods and 

 large lamellibranchs occur in concretions. 



Laona Sandstone. 



In the Genesee valley the Gardeau formation is terminated 

 by a thick mass of sandstone which is quarried under the name 

 of "bluestone" at Portageville. It is a finegrained, compact, 

 blue-gray sandstone lying in beds often fifteen feet thick which 

 are separated by thin seams of shale. This has been designated 

 the Nunda sandstone. In western New York this heavy bedded 

 sandstone is absent and the top of the Portage is of consequence 

 indefinite. A layer of sandstone twenty-two feet thick at 

 Forestville is considered to be in the horizon of the bottom layers 

 of this Nunda sandstone. This has been designated the Laona 

 sandstone from its exposure at Laona, Chautauqua county. 



All the upper beds of the Gardeau exposed in Erie county 

 show an ever increasing sandiness. The layers of sandstone 

 grow more frequent and thicker as the upper beds are reached 

 until they culminate in a series of beds from two to five feet 

 thick scattered through a vertical distance of a hundred feet. 

 Luther has ascribed some of these to the Laona sandstone. It is, 



