THE UNCONFORMITY BETWEEN THE BEDFORD AND 

 BEREA FORMATIONS OF NORTHERN OHIO 1 



WILBUR GREELEY BURROUGHS 

 Oberlin, Ohio 



In Lorain County of northern Ohio, 30 to 40 miles west of 

 Cleveland, occurs a striking unconformity between the Bedford 

 and Berea formations. In Ohio the Bedford formation is the low- 

 est member of the Waverly group, Mississippian system. It is an 

 argillaceous shale, the lower portion being a dark bluish gray, the 

 upper portion a chocolate or dark red color. The Berea formation 

 above is a bluish-gray, fine-grained sandstone. 



STRUCTURE OF THE BEDFORD AND BEREA FORMATIONS 



Dynamic movements of the region have taken place since the 

 laying-down of the Berea sandstone, both formations being uni- 

 formly folded. The general structure is that of a syncline whose 

 axis runs northeast and southwest. The red Bedford shale comes 

 to the surface on either side of this trough, which averages about 

 two miles in width. A great deal of the sandstone in the syncline 

 itself has been eroded away, exposing the red Bedford shale beneath. 

 The large rock trough contains minor anticlines and synclines, with 

 axes parallel to that of the large syncline. A compressional force 

 from the east and west has folded the axis of the northeast- 

 southwest syncline into a series of anticlines and synclines. At 

 South Amherst, in the region under discussion, the axis of the large 

 syncline is plunging toward the east. 



LENSES OF BEREA SANDSTONE IN THE HORIZON OF THE BEDFORD 



SHALE 



The Bedford forms steep banks where the streams cut against 

 it. As one goes along Beaver Creek, which flows just east of the 



1 The writer wishes to thank Professor G. D. Hubbard, of Oberlin College, for 

 criticism of the manuscript. The work was done in the Department of Geology at 

 Oberlin College. 



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