MARYLAND GEOLOGICAL SURVEY 65 



Darton^ jST. II., and Arthur Keith. Washington Folio, Dis- 

 trict of Columbia, Maryland and Virginia. 



U. S. G. S., Geol. Atlas, folio 70, Washington, 1901, 4to, 7 pp., 5 maps. 



A complete description of the geology of the Washington region including 

 the greater portion of Prince George's county. 



Shattuck, George Burbank. The Pleistocene Problem of the 

 JSTorth Atlantic Coastal Plain. 



Johns Hopltins Univ. Circ, vol. xx, 1901, pp. 69-75. 



Amer. Geologist, vol. — , 1901, pp. — . 



The views of McGee, Darton, and Salisbury concerning the Pleistocene 

 deposits are summarized and compared with the writer's views. The wave- 

 built terrace deposits are referred to four different formations, the Talbot, 

 Wicomico, Sunderland, and Lafayette, the first three of which constitute the 

 Columbia group. These formations are said to be separated by erosional 

 unconformities. 



1902. 



Bon STEEL, Jay A., and Party. Soil Survey of Prince George's 

 County, Maryland. 



Field Operations of the Bur. of Soils, 1901, pp. 173-210, fig. 6, pis. 21-25, 

 Washington, 1902. 



Contains a brief resume of the geology of the county and a description of 

 each of the types of soil recognized in the county. 



Clark, W. B. and Bibbins, A. Geology of the Potomac Group 

 in the Middle Atlantic Slope. 



Bull. Geol. Soc. Amer., vol. xiii, 1902, pp. 187-214, pis. xxii-xxviii. 



Contains a full discussion of the Potomac deposits with a map showing the 

 distribution of the four formations in Maryland. 



Darton, Nelson Horatio. Preliminary List of Deep Borings 

 in the United States. 



Part I, Alabama-Montana. 



U. S. Geol. Surv., Water-Supply and Irrigation Paper No. 57, 60 pp., Wash- 

 ington, 1902. 



Contains data in regard to some deep wells in the District of Columbia. 



RiES, Heinricii. Report on the Clays of Maryland. 



Md. Geol. Surv., vol. iv, 1902, pp. 203-505, pis. xix-lxix. 



Contains a complete description of the clay deposits and clay industries of 

 the State with many detailed descriptions of the clays of Prince George's 

 county. 



