Report on the Mines and Mining Exhibit. 343 



The clays of the mainland are all Quaternary, so far as is known. 

 The problems of the Quaternary formations in New York are by no 

 means solved, and it is not always possible to decide on the causes lead- 

 ing to the deposition of any particular body of clay by a single visit to 

 the locality. A great number of the deposits- are local and basin-shaped, 

 lying in the bottom of the valleys, which are often Ijroad and fertile. 

 They vary in depth from four to twenty or even fifty feet; as a 

 rule they are underlain by drift or by bedrock. The clay is generally 

 of a blue or bluish gray color, the upper few feet being weathered 

 mostly to a red or yellow. Stratification is rare, but streaks of marl 

 are common. In some of the beds small pebbles are found, usually of 

 limestone, and these have to be eliminated by special processes in the 

 manufacture. In many cases the clay is covered by a foot or more of 

 peat. The basin-shaped deposits are no doubt the sites of former 

 ponds or lakes, formed in many instances by the damming up of the 

 valleys, and which have been filled later with sediment of the streams 

 from the retreating ice sheet. The valleys in which these deposits lie 

 are usually broad and shallow. The broad valley of the Genesee river 

 between Mt. Morris and Rochester is an instance. The waters of the 

 river were backed up by the receding glacier for a time, during which 

 the valley was converted into a lake in which a large amount of 

 aluminous sediment was deposited. The material has been employed 

 for common brick. 



An idea of the depth of the clay and alluvium in the Genesee valley 

 may be had from the following table. The figures have been taken 

 from records of salt wells : 



PifEard, Genesee Salt Co., clay and gravel 64 feet. 



York, York Salt Co., clay ' 52 " 



PifEard, Livingston Salt Co., soil 158 " 



Cuylerville, soil 154 " 



Mt. Morris, Royal Salt Co., soil 184 " 



For other localities the following data are given : 



Aurora, blue clay 15 " 



Wyoming, Pioneer well, soil and clay 40 " 



There are a number of the clay deposits which are of sufficient 

 interest geologically, as well as commercially, to be mentioned in some 

 detail. Around Buffalo is an extensive series of flats underlain by red 

 clay. A thin layer of sand overlies the clay, and is of suitable 

 quality for tempering and molding. Similar deposits occur at several 

 localities to the north of the well-known ridge road and around Niagara 

 Falls, Tonawanda and La Salle, to the north of Buffalo, as well as south 

 of the city, along the lake shore. 



Prof. Hall mentions deposits of clay at the following localities : 

 At Linden, one mile south of Yates Centre ; along the shore of Lake 

 Ontario, east of Lewiston ; on Cashaqua creek deposits of tenacious 

 clay occur from the crumbling of tenacious green shales ; in Niagara 

 county beds of clay are said to occur in every town, but they often con- 

 tain considerable quantities of lime. 



