Geology of Long Island. 349 



have decomposed by oxidation, and the resulting ferric oxide 

 lias cemented the sand about them into a hard crust, while the 

 nodules in the clay beds which were protected from oxidation 

 have remained unaltered. 



North of Glen Cove, clays of various kinds occur at East and 

 West Islands, Dosoris', and at Matinnecock Village. At the 

 East Williston brickyard, near Mineola, there is a local deposit 

 of grey micaceous clay. The depth, of this, where excavated, 

 varies from 7 to 18 feet. The clay overlies white laminated 

 sands, stained with limonite, the upper surface of the sand being 

 cemented together for the depth of an inch by the yellow oxide. 

 Over the clay is about six inches of black alluvial earth. 



At the brick-yard on Centre Island, in Oyster Bay, there is a 

 deposit of brown sandy clay over a bed of more homogeneous and 

 tougher clay. These beds undulate in an east and v^est direction 

 or away from the shore, and the lower stratum contains shaly 

 concretions or claystones. About a mile north of the brick-yard, 

 it is said that a bed of white fire clay has been found at a depth 

 of 25 feet under the drift and sand. "A little west from the U. 

 S. Fish Hatchery, at the head of Cold Spring Harbor, is a bank 

 of stratified gravel 70 feet high. About 40 feet below the top 

 of this bank is an exposure of laminated sand and sandy clay 

 stained red, brown and yellow with oxide of iron, and a short 

 distance below, a chalybeate spring issues from the bank. The 

 clay deposit at Stewart's brick-yard, at Bethpage, is about 60 

 feet in depth. The surface stratum is a yellowish micaceous 

 clay, the lower part being mottled blue and yellow. It probably 

 was originally a gray or blue clay, its present yellow color being 

 due to the peroxidation and hydration of the iron contained. 

 Of this stratum there is about 35 feet ; below is about five feet 

 of reddish sandy clay, and beneath this a blue-black sandy clay 

 containing nodules of white pyrites. This stratum is about 25 

 feet deep and is underlaid by white sand. The beds are some- 

 what disturbed and folded, the uppermost being slightly undu- 

 lating, while the two lower appear to be raised in a fold trending 

 nearly E. and W. 



I am indebted to Mr. Lewis for the following section obtained 

 in digging a well at Jericho in 1878, on the premises of Mr. Jules 

 Kunz : 



