656 WILBUR GREELEY BURROUGHS 



Berea sandstone quarries at South Amherst, or Chance Creek on 

 the west, he will occasionally find the high banks covered by a 

 mass of Berea sandstone talus. This debris came from a lens of 

 sandstone in situ at the top of the bank, extending for 50 to 100 

 feet on the horizontal, and flanked on either side by red Bedford 

 shale. In places the sandstone is in thin beds 2 to 3 inches thick, 

 at other places in massive beds 3 to 4 feet thick. The lenses range 

 from 10 to 50 feet in total thickness. Their long axes run in a 

 general westward direction. No evidence of slumping is found in 

 connection with the banks at and in the vicinity of these lenses. 

 Neither can they be the bottom of synclinal troughs, for the dips 

 of their minor axes are not great enough to bring the sandstone to 

 the top of the bank of Bedford shale. The only answer to the 

 question of their origin is that there were once channels and depres- 

 sions in the Bedford shale which, on being filled with sand, ulti- 

 mately formed (in cross-section) the lenses as they now exist. 



So far as the writer is aware, nothing has ever been published 

 regarding this unconformity between the Bedford and Berea forma- 

 tions of northern Ohio, save in the Ohio Geological Survey Report, 

 Vol. II, published in 1874. This report mentions lenses in the 

 horizon of the Bedford shale north of Elyria, which is to the east- 

 ward of the region under discussion in this article. On p. 91 we 

 read, referring to the erosion of the Bedford prior to the deposition 

 of the Berea: "It is probably due to this fact that the red shale is 

 so frequently found to be wanting in the section." 



Mr. H. E. Adams, superintendent of the Ohio quarry at South 

 Amherst, Ohio, states that in the extreme southeast corner of 

 Lorain County, Berea grit occurs in lenses in the horizon of the 

 red Bedford shale exactly in the same manner as at South Amherst. 



The Bedford-Berea unconformity is not confined to Lorain 

 County, Ohio. Dr. Hubbard is authority for the statements that 

 "an unconformity occurs at the same horizon in- northwestern 

 Fairfield County near Lithopolis; and Professor Prosser believes 

 a similar break exists at the same horizon near Cleveland, Ohio, 

 but further work is there necessary." 



The sand-filled troughs in the erosion plane of the Bedford 

 formation which are visible along the streams are small and insig- 



