ABSTRACTS OF PAPERS 113 



HAMILTON aUOUP OF WESTERN NEW YORK 

 BY AMADEUS W. GRABAU 



(Abstract) 



The various subdivisions originally made by the author for the Hamilton 

 of Eighteen Mile Creek have been correlated with a similar number of sub- 

 divisions in central New York by the New York Survey. The validity of this 

 correlation will be considered and the facts suggesting that an error has been 

 made will be given. A new series of names for these subdivisions will be 

 prepared. A brief comparison with the Traverse group of Michigan will be 

 made. 



Presented in abstract extemporaneously. 



Discussion 



A general and extended discnssion of the black sliale prol)lem then 

 followed, which was participated in by IMessrs. David White, Edward M. 

 Kindle, I. C. White, Charles S. Prosser, A. W. Grabau, E. 0. Ulrich, 

 H. P. Gushing, M. Y. Williams, and A. F. Foerste. 



EXTENSION OF MORRISON FORMATION INTO NEW MEXICO 



BY N. H. DARTON 



(Abstract) 



During the past few years the author has examined nearly the entire out- 

 crop zone of the Red Beds and their contact with overlying rock,s. It has 

 been found that in the northern half of the State the Red Beds are overlain 

 by deposits having all the characteristics of the Morrison formation in Colo- 

 rado, and in part of the area the outcrop is continuous from one State into 

 the other. 



Presented by title in the absence of the author. 



GEOLOGICAL RECONNAISSANCE OF PORTO RICO 

 BY CHARLES P. BERKEY 



(Abstract) 



This pai)er was l)asod on work of exploration continued for a month during 

 the season of 1914 under the joint support of the New York Academy of 

 Sciences and the insular government of Porto Rico. The primary purpose of 

 the reconnaissance was to determine the character and structural relations of 

 the princijial geologic formations of the island and to carry forward investi- 

 gations far enough to indicate some of the problems that should be made the 

 objects of special study in work which is to follow. Systematic observations 

 were made on two lines entirely acro.ss the island in sufficient detail to furnish 

 data for general geologic cross sections. These sections b.ive been drawn and 

 illustrate the fundamental structure of the island, as well as the geologic 

 basis of Its relief. 



