468 



Report <>f the State Geologist. 



Gneiss. A mile southeast of Soiithfield and along the Erie railroad is a 

 large quarry in the quartzose gneiss. It is operated solely for road-paving 

 purposes. The rock is crushed and screened at the quarry. 



Mr. Josiah Mead is the owner. The material is all shipped to Colfax Ar 

 Steele, of Paterson, N. J. 



Brick-Clays. These are the only grades of clay found in the county. 

 The important and most extensive development of this material is along the 

 Hudson river, in whose valley there exists the greatest brick manufacturing 

 industry of the United States. The clay beds extend almost continuously 

 from Roseton on the north to Cornwall on the south. The linns engaged in 

 the manufacture of brick in this area together with the location and the 

 capacity of their brickyards, are enumerated in the following list : 



Locality. 



Workers. 



Owner. 



Capacity 

 in millions. 



Roseton, . . 



. Jova Brick Works, 



Jova Brick Works, 



22 





J. Hose &, Co., 



Rose Brick Co., 



40 



New Windsor, E. Lang, 



E. Walsh, 



8 





J. Gillis, 



J. Gillis, 



4 





H. Davidson's Sons, 



H. Davidson's Sons, 



4 





W. Lahey, 



W. Lahey, 



10 





David Carson, 



David Carson, 



4 



Cornwall, . 



. . C. A. <fc A. P. Hedges, 



C. A. & A. P. Hedges, 



10 



Goshen, , , , 



T van Lengen, 





2 



The chief market for all, except the last on the list, is New York city 

 and Brooklyn. 



A detailed account of these clay beds has been given by the writer 

 in the Tenth Annual Report of the New York State Geologist, and only a 

 general mention of them need be made here. The greatest known thickness 

 of the Hudson river clay is at Roseton, where there are 108 feet of clay above 

 the river level and 1 7< > feet below it, as determined by a drive-well, giving a 

 total thickness of 278 feet. Between Newburgh and Cornwall the clay is 

 generally tough, with more or less boulders scattered through it, and there is 

 a varying cover of delta material. The clay at Roseton and Cornwall-on- 

 Hudson is, on the contrary, well stratified and very soft, but it is likew ise 

 overlaid by delta deposits. The soft mud process of manufacture is the one 

 used at all the yards, and only common brick is made. 



The following is an analysis of the clay used by the Jova Brick Works 

 and furnished by them : 



