CONTENTS V 



Page 



Recent remarkable gold "strike" at the Cresson Mine, Cripple 

 Creek, Colorado [abstract and discussion] ; by Horace B. 



Patton 84 



Platinum-gold lode deposit in southern Nevada [abstract] ; 



by AuoLPH Knopf 85 



(Organic origin of some minei'al deposits in unaltered Paleo- 

 zoic sediments [abstract and discussion] ; by Gilbert van 



Ingen 85 



Isostasy and radioactivity ; I'resideutial address by George F. 



Becker 86 



Session of Wednesday, December 30 87 



Report of Auditing Committee 87 



Titles and abstracts of papers presented in general session and 



discussions thereon 87 



Revision of pre-Cambriau classification in Ontario [abstract 

 and discussion] ; by Willet G. Miller and Cyril W. 



Knight 87 



North American continent in Upper Devonic time [abstract 



and discussion] by Amadeus W. Grabau 88 



Symposium on the passage from the Jurassic to the Cretaceous. . 90 

 Titles and abstracts of papers presented before the First Section 



and discussions thereon 90 



Type of rifted relict mountain, or rift mountain [abstract 



and discussion] ; by John M. Clarke 90 



Evidence of recent subsidence on the coast of Maine [abstract 



and discussion] ; by Charles A. Davis 91 



Basic rocks of Rhode Island : their correlation and relation- 

 ships [abstract and discussion] ; by A. C. HawkIxXS and 



C. W. Bkowx 92 



Acadian Triassic fal)stract and discussion] ; by Sidney 



Powers 93 



(Geological history of the Bay of Fundy [abstract] ; by Sidney 



Powers 94 



Titles and al)stracts of papers presented before the Second Sec- 

 tion 95 



Alexandrian rocks of northeastern Illinois and eastern Wis- 

 consin [al)stract] ; by T. E. Savage 95 



Olentangy shale and associated deposits of northern Ohio 



[abstract] ; by Clinton R. Stauffer 95 



Diastrophic importance of the unconformity at the base of 



the Berea sandstone in Ohio [abstract] ; by H. P. Cushing. 96 

 Kinderhookian age of the Chattanoogan series [abstract] ; by 



E. O. Ulrich 96 



Titles and abstracts of papers presented before the Third Section 



and discussions thereon 99 



Origin of the iron ores at Kiruna, Sweden [abstract] ; by 



Reginald K. 1 » at.y 99 



Origin of the Rocky MouiitMiii jihosphate deposits [abstract] : 

 by Eliot Black welder 100 



