CONTENTS 3 



Page 



Session of Wednesday evening 112 



Presidential address and smoker 112 



After effects of igneous intrusion (title) ; Presidential address by 



James F. Kemp 113 



Session of Thursday, December 29 113 



Report of the Auditing Committee 113 



Symposium on isostasy 113 



Theory of isostasy — a geological problem [title] ; by William P>owie 113 

 Condition of the earth's crust and the earlier American gravity 



determinations [title] ; by George R. Putnam 113 



Some considerations touching on isostasy [title] ; by H. O. Wood. 114 

 Isostasy and earth movements [title] ; by Harry Fielding Reid. . . 114 



Isostasy and applied geology [title] ; by James F. Kemp 114 



Folding of mountain ranges — the argument from isostasy [title] ; 



by Sir Sidney Burrard 114 



Isostatic compensation considered as a cause of thrusting [title] ; 



by Andrew C. Lawson 114 



Isostasy and rock density [title] ; by Henry S. Washington 114 



Weight of sediments per unit volume [titl] ; by Alfred C. Lane. . . 114 



Role of isostatic stress [title] ; by Bailey Willis 114 



Session of Thursday afternoon 115 



Titles and abstracts of papers presented at the afternoon session and 



discussions thereon 115 



Comparative study of the Nebraskan and Kansan tills in Iowa 



[abstract] ; by George F. Kay 115 



Further data on the differentiation of the glacial drift sheets of 



northern Illinois [abstract and discussion] ; by M. M. Leighton . 116 

 Late Pleistocene history of the Lower Mohawk and Middle Hud- 

 son region [abstract]; by James H. Stoller 117 



Ablation of the eastern lobe of the Wisconsin ice-sheet [abstract] ; 



by John H. Cook 117 



Preliminary notes on the shorelines of glacial Lake Nashua, near 



Fitchburg, Massachusetts [abstract] ; by Thomas C. Brown.... 118 

 Map of the Pleistocene lakes of the Basin-and-Range province, 



and its significance [abstract and discussion] ; by O. E. Meinzer 118 

 Is the channel of the Missouri River through North Dakota of 



Tertiary origin? [abstract] ; by James E. Todd 120 



Former courses of the Androscoggin River [abstract] ; by Irving 



B. Crosby 121 



Peneplains and the geographic cycle ; by W. M. Davis 121 



Retrograding of offshore bars [abstract] ; by Douglas W. Johnson 121 

 Role of cross waves in the formation of tomboloes and points [ab- 

 stract and discussion] ; by Roswell H. Johnson 122 



Geology of the Colorado River in southeastern Utah [abstract] ; 



by C. R. Longwell, H. D. Miser, R. C. Moore, and Sidney Paige. 122 

 Cambrian succession of northwestern Vermont [abstract and dis- 

 cussion] ; by Arthur Keith 123 



