BROAD GEOLOGIC FEATURES 483 



of its nature from point to point. Through the literature of the state 

 geological surveys of Pennsylvania, West Virginia, Kentucky, Illinois, 

 and of the United States Geological Survey there are numerous refer- 

 ences that bear on the subject. But the object of this paper is to point 

 out the connection between known segments and leave the matter of de- 

 tailed descriptions for a more complete report, which should be prepared 

 by some one who has the time at his command to assemble the known 

 data and to make additional observations in the field. It will be found 

 that the nature of the disturbance varies from a low anticline, with dips 

 of from 25 to 100 feet per mile in Pennsylvania, West Virginia, and 

 eastern Kentucky, to a fault zone showing displacements as much as 1,000 

 feet westward through Kentucky and across southern Illinois. 



