TITLES AND ABSTRACTS OF PAPERS 



139 



Saliua aj:i» (Silurian*, and liincsntnos and irray and black shales, with thin 

 limestones near top and bottom, which are to be correlated with the Onondaga 

 limestone, the TuUy limestone, the Huron shale, and the I'ortage shale, of the 

 Devonian system of New York State. Thin sheets and narrow dikes of trap 

 cut the Onondajja and older sediments. 



Presented by title in the absence of tlie author. 



Ah'h'A\aFMi:yTS ron i/)/)/770\.4L ueoiahucai. surveys jy the 



W EST INDIES 

 BY THOMAS WAYLAM) VAVGHAN 



{ Abstract) 



The pajier gave a comprehensive statement regarding the arrangements now 

 in force for geological surveys of the Dominican and Haitian republics. 



I'ead from nianuscri]U. 



(lEOUKiKWL RECOXXAISSAyCE OF THE DOMINICAN REPUBLIC 

 BY CHARLES WYTHE COOKE 



l^resented by title in the absence of the author. 



At the second section formed for the afternoon — E. W. Shaw, chair- 

 man, and C. X. Fenner, secretary — the following program was offered : 



DIFFEREyTIATIOy BY DEFORMATION 

 BY N. L. BOWEN 



(Ahstrart) 



The problem was raised <»f the possible effects of deformation of an igneous 

 mass during crystallization. Suggestions were made as to how such action 

 may aid in the production of mono-mineralic masses of extreme purity with 

 [jarticular reference to anorthosites. The i)Ossibility was considered that some 

 IKTid<»tite dikes may be merely constricted i)arts of basaltic dikes, and that 

 c<»mposite dikes arc a likely comi>lementary manifestation. The origin of 

 [irimary banding, of border facies. and of the so-calknl Atlantic and Pacific 

 families of igneous rocks was <'onsidered in this connection. 



Presented without notes. 



Discussed by Messrs. K. A. Daly, A. i\ Lane. Whitman Cross, and 

 J. E. Spurr. 



