184 Agricultural Geology of Onondaga County. [April, 



by a cut of the road about half a mile from the house of Mr. 

 Geddes of Fairmount. It resembles a pulverulent gypsum or a 

 gypseous clay, and it is not improbable that it was gypsum, but 

 has been changed to a marl {^carbonate of lime), by the decompo- 

 sition of the sulphate of lime into a carbonate. This marl bed 

 underlies several acres, and is exposed for 20 or 30 feet in depth. 

 Two hundred grains infused in water gave 



Sulphate of lime, - - - 2.98 

 Sulphate of magnesia,- - 0.44 



Organic matter, _ - _ ].50 



By far the greater part of the mass is a fine brownish carbon- 

 ate of lime, and in many places would be extremely valuable as 

 a manure. 



A concreted marl in the same vicinity, gave, in two hundred 

 grains. 



Soluble matter, - - - .62 

 Saline, - - - - .24 



Vegetable, - - - - .54 



Some of the small streams which flow over peat and marl 

 beds, transfer those materials to some lodging place where they 

 accumulate in a very fine state of subdivision. This matter is 

 worthy of attention. It consists of 



99.74 



The mechanical state in which this debris is makes it extreme- 

 ly valuable for a compost. The largest accumulation was near 

 the house of Mr. Geddes, and was brought down the stream 

 running through his estate. Peat is also extremely common, and 

 will in time become valuable for many purposes; for agriculture 

 and fuel. 



