VI BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Page 



Evidence in the Helena- Yellowstone Park region, Montana, of 

 the great Jurassic erosion surface [abstract] ; by D. Dale 

 ' CONDIT IGI 



"Giant ripples" as indicators of paleogeography [abstract] ; by 



Walter II. Bucher 161 



Symposium on the Interpretation of Sedimentary Rocks 1G2 



The problems stated ; by A. W. Grabau 162 



Significance of sedimentary rhythm ; by Joseph Baerell. . . . 162 



Diagnostic characteristics of marine elastics ; by E. M. Kindle 162 



Characteristics of continental elastics and chemical deposits ; 

 by Eliot Blackwelder 162 



Significance of sorting in sedimentary rocks ; by E. W. Shaw . 163 



Chemical and organic deposits of the sea ; by T. W. Vaughan 163 



Deformation of unconsolidated beds in Nova Scotia and south- 

 ern Ontario [abstract] ; by E. M. Kindle 163 



Illustrations of the deformation of limestone under regional 

 compression [abstract] ; by David H. Newland 163 



Silver City quartzites, a Kansas metamorphic area [ab- 

 stract] ; by W. H. Twenhofel 164 



Orographic origin of ancient Lake Bonneville [abstract] ; by 

 Charles R. Keyes 164 



Persistence of vents at Stromboli and its bearing on volcanic 

 mechanism [abstract] ; by H. S. Washington 165 



Pleistocene deformation near Rutland, Viermont [abstract] ; 

 by Arthur Keith 165 



Geology of the Lau Islands, Fiji [abstract] ; by Wilbur Gar- 

 land Foye 166 



Titles and abstracts of papers presented before the afternoon ses- 

 sion and discussions thereon 166 



Intraformational structure in the Ordovician limestone of cen- 

 tral Pennsylvania [abstract] ; by Richard Montgomery 

 Field 166 



Pleistocene and post-Pleistocene geology of Waterville, Maine 

 [abstract] ; by Homer P, Little 167 



Age and origin of the red beds of southeastern Wyoming [ab- 

 stract] ; by S. H. Knight 168 



General stratigraphic break between Pennsylvanian and Per- 

 mian in western America [abstract] ; by Willis T. Lee. . . . 169 



Amsden formation of Wyoming and its fauna [abstract] ; by 

 E. B. Branson and D. K. Greger 170 



Remarkable geologic section near Columbia, Missouri [ab- 

 stract] ; by E. B. Branson 170 



Satsop formation of Washington and Oregon [abstract] ; by 

 J. Harlen Bretz 170 



Geology of the area of Paleozoic rocks in the vicinity of Hud- 

 son and James Bays, Canada [abstract] ; by T. E. Savage 

 aiwi F. M. Van Tuyl 171 



Lower Paleozoic rocks of the southern New Mexico region [ab- 

 stract] ; by N. H. Darton 172 



