770 ABSTRACTS OF PAPERS 



structure of the northern Appalachians. The question of the origin of canoe- 

 shaped folds was discussed briefly. Finally, the relation of the drainage 

 system to the structure was referred to. 



Discussion 



Dr. Arthur Keith: In the Appalachian folding I have seen south of the 

 Potomac the character of the folding is directly due to the character of the 

 strata involved. Thin-bedded rocks make small folds and crumplings, and 

 massive rocks make large and smooth folds. According as the strata at the 

 surface are heavy or thin-bedded, the character of the folding which we see 

 varies. It varies also as the position of the massive beds changes in the sec- 

 tion. The pressure is transmitted mainly by the massive beds. Where they 

 occupy the lower part of the section the folds have a tendency to be upright, 

 and where they are in the upper part of the section there is a strong disposi- 

 tion toward overturning. The changes and interactions of these factors make 

 marked and general changes in the nature of the deformation from north to 

 south along the Appalachians. Folding, which is distinctive of Maryland and 

 Pennsylvania, with comparatively little overturn, passes into folding and fault- 

 ing with much overturning in lower Virginia, and into faulting with subordi- 

 nate folding in Tennessee, Georgia, and Alabama, the overturning at the same 

 time becoming more pronounced. 



80MB INSTANCES OF FLOWING WELLS ON ANTICLINES 

 BY F. G. CLAPP 



(Abstract) 



The paper described several unrecorded flowing artesian wells of a peculiar 

 type. The flows are from unproductive oil wells in the northern Appalachian 

 region. The first mentioned instance is on the Eureka-Volcano-Burning- 

 Springs anticline in Pleasants County, West Virginia. This anticline consists 

 of an alternating series of saddles and domes, and the flowing wells are situ- 

 ated on a saddle of the anticlinal crest midway between two domes. The 

 source of the water is one of the Carboniferous sandstones, which does not 

 rise high enough in the anticline to give the requisite head, the latter being 

 presumably due to pressure transmitted to the water in the sandstone from 

 overlying porous formations in the domes of the anticline. The second in- 

 stance is In Beaver County, Pennsylvania. The wells are situated high up on 

 the flank of the Frederickstown anticline. The water comes from depths of 

 less than 100 feet, and overflows between the drive pipe and the casing of the 

 wells, the head being due to pressure transmitted from more superficial for- 

 mations in near-by hills. Analogous instances of transmitted pressure were 

 cited from Niagara limestone wells in Indiana, 



