332 



CEMENTS, LIMES, AND PLASTERS. 



TABLE 154. 

 PORTLAND-CEMENT PRODUCTION OF THE LEHIGH DISTRICT, 1890-1902. 



Northeast of Stewartsville, N. J., the cement-beds outcrop at fre- 

 quent intervals in the Kittatinny Valley all the way across New Jersey 

 and a few miles into Orange County, N. Y. The exact locations of 

 these deposits, with numerous analyses of the cement rocks, are given 

 in the Annual Report of the State Geologist of New Jersey for 1900, 

 pages 41-95. Many detailed maps in this report show the outcrops 

 very precisely. 



Southwestward from Reading the Trenton beds outcrop in a belt 

 crossing Lebanon, Cumberland, and Franklin counties, Pa., passing 

 near the tows of Lebanon, Harrisburg, Carlisle, and Chambersburg. 

 In Maryland the Trenton rocks occur in Washington County, while in 

 West Virginia and Virginia they are extensively developed. The dis- 

 tribution of these rocks in Virginia is discussed in the papers by Messrs. 

 Bassler and Catlett, cited in the list on page 333. 



Throughout this southern extension of the Lehigh rocks, the Tren- 

 ton is not everywhere an argillaceous limestone, but it is frequently 

 so, and it is always very low in magnesium carbonate. It is therefore 

 probably safe to say that in southern Pennsylvania, Maryland, West 

 Virginia, and Virginia the Trenton rocks are everywhere good Port- 

 land-cement materials, though in some cases they will require pure 

 limestone, and in other places clay, to bring them to proper composition. 



Cement Rocks in Other States. 



Limestones sufficiently clayey to be called " cement rocks" are not 

 bv any means confined to the Lehigh district, nor even to the imme- 



