MAUYLAXD GEOLOGICAL SURVEY 53 



McGee, W J. Three Formations of the Middle Atlantic Slope. 



Amer. Jour. Sci., 3d ser., vol. xxxv, 1888, pp. 120-143, 328-331, 367-388, 448- 

 466, plate ii. 



The three formations discussed are the Potomac (now divided into four 

 formations), the Appomattox (Lafayette) and the Columbia (now divided 

 into three formations.) These are described in far greater detail than had 

 ever been done before and the conclusions reached vary but little from the 

 views held at the present time. 



McGee, W J. The Columbia Formation. 



Proc. Amer. Assoc. Adv. Sci., vol. xxxvi, 1888, pp. 221-222. 



The Columbia formation overlying unconformably the Cretaceous and 

 Tertiary deposits of the Atlantic Coastal Plain is said to consist of series of 

 deltas and terraced littoral deposits. It is said to pass under the terminal 

 .moraine to the northward. The Columbia materials are supposed to have 

 been laid down during a period of glaciation long preceding the glacial epoch 

 during which time the terminal moraine was formed. 



Maecou, Jules. American Geological Classification and Nomen- 

 clature. 75 pp. Cambridge, Mass., 1888. 



The writer mentions a specimen of Eycad found in association with pieces 

 of petrified wood and broken bones "on the farm of Dr. Jenkins, one mile 

 south of the Baltimore and Washington railroad, sixteen miles from Wash- 

 ington, Prince George's county, Maryland." He correlates the deposit in 

 which the specimens were found with the Purbeck formation of England. 



Uhlek, p. R. The Albirupean Formation and its nearest relatives 

 in Maryland. 

 Proc. Amer. Phil. Soc, vol. xxv, 1888, pp. 42-53. 

 Discussion by H. Carvill Lewis and A. Heilprin (pp. 53-54.) 

 In this article the writer proposed the name of "Baltimorean" for the basal 

 Potomac deposits and "Albirupean" for the sands that overlie the basal beds 

 and which are firmly indurated in several places in the State. One of the 

 places where the sandstone is described is in "the vicinity of the fork of the 

 Great Patuxent river, in Prince George's county." The pre-Tertiary deposits 

 of the Coastal Plain are said to consist of the two formations named above 

 and the marine greensands. In the discussion Professors Lewis and Heilprin 

 disagreed with Dr. Uhler as they claimed he had included some Paleozoic 

 quartzites with the mesozoic sandstones in the albirupean formation. 



TJhlek^ p. p. Observations on the Eocene Tertiary and its Cre- 

 taceous Associations in tlie State of Maryland. 



Trans. Md. Acad. Sci., vol. i, 1888, pp. 11-32. 



Many details concerning the distribution, lithologic characteristics, and 

 fossil content of the Eocene and Cretaceous deposits of this county are given. 



