98 PROCEEDINGS OF THE AMHERST MEETING 



reflects the configuration of the granite surface. To the formation of these 

 folds, controlled by relations to the granite, is largely due the existence of the 

 central Kansas oil and gas fields. 



Presented extemporaneously, with lantern-slide illustration. 



Discussion 



Discussed by William Bowie, who said that pendulum stations were to be 

 established in the region discussed by Dr. Moore for the determination of 

 gravity. These may lead to ability to predict presence of crystalline rock 

 ridges. 



INTRAFORMATIONAL CORRUGATED ROCKS 

 BY WILLIAM J. MILLER 



(Abstract) 



It is the purpose of this paper to enter rather fully into a consideration of 

 intraformational corrugated rocks. Examples are discussed from formations 

 ranging in age from Archeozoic to Postglacial. Assigned causes for the corru- 

 gations include the following : differential movements accompanying regional 

 folding, thrust and normal faulting, and pressure of intruding magmas, com- 

 pression of weaker layers between more resistant layers, differential sliding 

 due to gravity, subaqueous gliding, differential weighting, crowding action of 

 ice, swelling due to crystallization, magmatic flowage, and magmatic injection. 



Read from manuscript and illustrated by lantern slides. 



Discussion 



Discussed by James H. Lees, as follows : Along Bayer Valley, in Crawford 

 County. Iowa, is an exposure showing valley gravels, as described in abstract 

 in Bulletin of the Geological Society of America, 1921. Above the gravels are 

 intercalated bands of sand and loess which are very much contorted, while 

 the underlying gravels are horizontal. These intercalated bands have a total 

 thickness, as exposed, of about 3 feet. The individual bands are only a few 

 inches thick. The cause of the contortion is in doubt, but it may be slumping 

 down the valley walls. 



STRUCTURE OF THE PRE-PENNSYLVANIAN ROCKS OF THE BIG STONE GAP 



AREA, WISE COUNTY. VIRGINIA 



BY GEORGE W. STOSE 



(Abstract) 



The area is an anticlinal valley between Stone Mountain and Powell Moun- 

 tain, monoclinal ridges capped by Lee conglomerate. The anticlinal rises 

 toward the southwest and exposes Clinch sandstone, which forms Walden 

 Ridge at the county line, and underlying rocks down to Knox dolomite to the 

 southwest. The anticline is sharply overturned and overthrust at the center 



