"SLIDES" IN THE CONEMAUGH FORMATION 341 



must, however, express his indebtedness to the reports of the 

 West Virginia Geological Survey; also to Professor S. B. Brown, 

 his colleague and chief, who has spent much time in acquainting 

 him with the area. He is especially obligated to Dr. I. C. White, 

 state geologist, and to Mr. David B. Reger, assistant state geologist, 

 for their thoroughgoing review of the paper and constructive criti- 

 cisms which have been freely used in its revision. 



The slides studied occur in the Conemaugh Formation, of the 

 Pennsylvanian epoch. This is a series of alternating beds with 

 shales predominating, in this locality approximately horizontal. 

 The total thickness outcropping averages about six hundred feet. 

 All shale members when exposed a short time to weathering agencies 

 break down, if sufficient water is present, into a slippery, claylike 

 mud. This creeps, slides, or even flows until the angle of repose 

 is attained. 



SKdes, in the aggregate, constitute one of the big factors in the 

 base-leveling of the area. Where numerous they produce a 

 typical topography with features resembling those produced by 

 glaciation and drainage. Less prominent forms frequently asso- 

 ciated with slides are the "hoodoos" and ice pinnacles. 



The Conemaugh is in a measure representative of several later 

 formations of the Carboniferous, which show closely corresponding 

 topography over much of the northern part of the state where such 

 shaly sediments prevail. 



While a single shde is rarely responsible for any great damage, 

 in the aggregate sHdes become very effective. The total direct and 

 indirect loss amounts to a heavy toll yearly. Some of the damage 

 may be prevented by proper precautions, but the problem is too 

 big for the adoption of absolute preventive measures. 



GEOGRAPHY 



The area studied with reference to slides is in Monongalia 

 County, West Virginia, about five miles south of the Pennsylvania 

 boundary. Morgantown may be considered the center. Through 

 the area winds the Monongahela River. The Indians recognized 

 the unstable character of the lands adjacent to the Monongahela by 

 this name, which translated means "River of the Caving Banks." 



