in the Cayuga Lake Region. 



245 



oblique pressure when it could hardly have done so in the 

 face of direct compression. 



The occurrence of the three above faults in such close 

 association with a large sized stream of extensive cutting 

 power brings up a question which may be raised by some. 

 Along the banks of many of the streams in the vicinity of 

 Cincinnati, Ohio, there occur in the Eden shale small over- 

 turned folds, sometimes advanced to the stage of thrust 

 faulting. (Fig. 10.) These are usually found on the 



Fig. 10. — Fold in Eden shale, West Fork Cr., Cincinnati, O. Supposed 

 to be due to relaxation resulting from stream erosion. 



under-cut side of terraces and are beginning to be recog- 

 nized as produced by relaxation due to rock removal by 

 stream erosion, rather than by direct pressure. These 

 streams are all post-glacial whereas Salmon Cr., N. Y., 

 runs in a valley recognized as pre-glacial. The horizom 

 tal fault at the Falls has certainly no connection with a 

 terrace though the one by the bridge has some such rela- 

 tion and to a post-glacial terrace at that. However, they 

 appear to be so in accord with the rest of the evidence 

 concerning the diastrophic history of the region that it 

 hardly seems necessary to call in outside evidence for 

 their explanation. 



A second type of faulting as shown in the shale mem- 



Am. Jour. Sci.— Fifth Series, Vol. Ill, No. 16. — Apbil, 1922. 

 18 



