TITTLES AND A13Sa^RACTS OF PAPERS 149 



number of other valleys in the driftless area reveals the same rock terraces, 

 the lower ones occasionally preserving chert gravels which do not seem to 

 necessitate earlier cycles of erosion. 



Presented by title in the absence of the author. 



PLEISTOCENE DEPOSITS IN THE SUN RIVER REGION, MONTANA 

 BY EUGENE STEBINGEK AND MARCUS I. GOLDMAN 



(Ahstract) 



This paper describes the southward extension to and beyond Sun River of 

 phenomena observed by W. C. Alden and others in the vicinity of the Glacier 

 National Park in 1911 and 1912. Deposits of the later (Wisconsin) stage of 

 mountain glaciation in this region and the variations in the plainsward exten- 

 sion of the different glaciers of this epoch are first described. The high level 

 gravels on flat-topped ridges, remnants of the Blackfoot peneplain in this re- 

 gion, are then discussed. The absence of definite evidence of pre-Wisconsin 

 glaciation in these gravels is probably due to one or both of two causes: (1) 

 A relatively slight extension of the glaciers on the plains, similar to that dur- 

 ing the Wisconsin stage, so that the glacial deposits were not laid down be- 

 yond the area of erosion of the active mountain streams; (2) the absence in 

 the mountains glaciated of the compact, fine-grained argillites of the Glacier 

 Park section, so well suited to the preservation of glacial markings. On ac- 

 count of these facts the absence of high level glacial deposits is not believed 

 to indicate the absence of the older glaciation in this region. Map of the area 

 described will be placed on exhibition. 



Presented by title in the absence of the authors. 



LARGE ROCK SLIDE IN THE WIND RIVER MOUNTAINS OF WYOMING 

 BY E. B. BRANSON 



(Abstract) 



A large rock slide, four to five miles long by one-fourth to one-half mile 

 wide, occurs in Bull Lake Creek Canyon, in the Wind River Mountains, 50 

 miles northwest of Lander, Wyoming. It owes its glacier-like motion to the 

 slumping of great masses of Cambrian and Ordovician limestone on slippery 

 Cambrian shales that dip eastward about 10 degrees. 



Presented in abstract extemporaneously. 



Brief remarks were made by Prof. G. F. Wright. 



SAVING THE SILTS OF THE MISSISSIPPI RIVER 

 BY WALLACE W. ATWOOD AND RODERICK PEATTIE 



(Abstract) 



Much of that portion of the plain of the lower Mississippi Valley which is 

 not actually swamp is in danger of flood, and is surrounded by wide stretches 



