5'^ THE PHYSICAL FEATUKES OF TRIXCE GEORGE S COUNTY 



ScHARF, J. Thomas. The jSTatural Resources and Advantages of 

 ]\rai\vland, being a complete description of all the counties of the 

 State and the City of Baltimore. Annapolis, 1892. 



Contains a general geographic description of Prince George's county with 

 brief statements of the mineral products. 



Uhler, p. R. Albirupean Studies. 



Trans. Md. Acad. Sci., vol. i, 1890-92, pp. 185-202. 



The Albirupean and Potomac formations are described in detail and many 

 references made to localities in this county. Much of Uhler's Albirupean 

 formation is now referred to the Magothy, particularly the lignitic black 

 clays while parts are included in the Potomac group. 



AViLLiA^MS, G. H., and Clark, Wm. B. Report on short excursions 

 made by the Geological Department of the University during the 

 Autumn of 1891. 



Johns Hopkins Univ. Cir. No. 95, vol. xi, 1892, pp. 37-39. 



The section of Potomac, Marine Cretaceous, Eocene, and Pleistocene strata 

 exposed at Fort Washington is briefly described. 



189-3. 



Clark, W. B. Physical Features [of ^Maryland]. Maryland, its 

 Resources, Industries, and Institutions. Baltimore, 1893, pp. 11-5-1. 



Contains short descriptions of the topography, climate, water supply, and 

 water power of the different portions of the State. 



Dartox, X. II. The Magothy Formation of Northeastern Mar>'- 

 land. 



Amer. Jour. Sci., 3d ser., vol. xiv, 1893, pp. 407-419, map. 



The Magothy formation is differentiated from other Cretaceous strata with 

 which the deposits had previously been included. The distribution and 

 characteristics of the formation are discussed and many local details 

 described. A map showing the distribution of the formation is given. 



Hill. Robert T. Clay Materials of the United States. Mineral 

 Resources United States, 1891. Washington, 1893. 



Brief mention is made of the Columbian and Potomac clays of the county 

 and of the District of Columbia. 



Keysejj, W. Iron. Maryland, its Resources, Industries and Insfi- 

 tutions, pp. 100-112. Baltimore, 1893. 

 An historical discussion of the iron industry in Maryland. 



