736 ABSTRACTS OF PAPERS 



GEOGRAPHICAL DESCRIPTIONS IN THE FOLIOS OF THE GEOLOGIC ATLAS OF 



THE UNITED STATES 



BY W. M. DAVIS 



(Abstract) 



The Folios of the Geologic Atlas of the United States usually open with an 

 empirical geographical description of the district concerned, and on a later 

 page give, under the appropriate heading, Historical Geology, an explanatory 

 account of the evolution of the same features. Under the second heading we 

 find some of the best examples of modern treatment of physiographic evolu- 

 tion ; but under the first heading we find an undue conservatism in the reten- 

 tion of old-fashioned empirical terms in place of more recently introduced 

 genetic terms. In the treatment of the geological problems, which naturally 

 occupy the greater part of the text, explanatory treatment phrased in modern 

 technical terms is entered upon at once, as it should be. A similar explana- 

 tory treatment of geographical features in technical terms would be consistent 

 with the recent progress of geographical research. 



QUANTITATIVE CLASSIFICATION OF METEORITES 

 BY OLIVER C. FAEEINGTON 



{Abstract) 



Earlier systems of classification of meteorites are reviewed, and the results 

 of classifying meteorites according to the quantitative system are given. The 

 number of meteorites classified reaches about one hundred and twenty-five. 

 The meteorites are all, except one, in the classes of dofemanes and perfemanes. 

 The dofemanes are persilicic, dosilicic, and silico metallic ; the perfemanes 

 range from persilicic to permetallic. Nearly all are perpolic. From perpyric 

 all gradations occur to perolic. All are permirlic. Most are permiric and 

 domagnesic. While the majority fall outside of the groups in which terrestrial 

 rocks occur, the groups of wehrlose, argeinose, maricose, and websterose are 

 represented. 



MOLDAVITE QUESTION 

 BY GEORGE P. MERRILL 



{Al)stract) 



The paper discusses the supposed meteoric origin of the peculiar glass bodies 

 known under the names moldavite, billitonite, australite, obsidian bombs, 

 etcetera, and shows that the peculiar surface markings are closely comparable 

 to etchings produced by solfataric emanations or natural weathering, and not 

 at all like those on known meteorites. A new form from South America is 

 described. 



CLINTON SAND AS A SOURCE OF OIL IN OHIO 

 BY J. A. BOWNOCKER 



(Abstract) 



The stratigraphical position of the Clinton sand, its thickness, texture, and 

 other physical properties. Geographical area where found. Areas producing 



