768 JESSE E. HYDE 



sediments. are of deltal origin, then the outcrop belt in central Ohio 

 appears to be that portion of the floor of a marine interior sea which 

 lay just off the front of a delta and was invaded by lobes from it. 

 It appears, however, that no portion of the outcrop sediments have 

 been deposited subaerially. The shoreline perhaps lay at no great 

 distance to the southeastward, possibly only a few miles. The sea 

 must have been one of quiet waters compared with the open ocean, 

 otherwise the waves would have destroyed the fairly sharp lines 

 of the facial boundaries. 



It is, perhaps, unexpected to learn that these conglomeratic 

 sandstones had their origin in the Appalachians. The paragraph 

 quoted above from Stevenson's carefully considered work indicates 

 how far it was from the thought of one who knew the whole prob- 

 lem. Certainly the deep-well records so far published from south- 

 eastern Ohio lead one to believe that the corresponding portion of 

 the column under cover is largely shale. Well records, however, 

 are very unreliable except when samples are taken, and usually but 

 little attention is really paid by the driller to any except the few 

 horizons that are well known to him and are used by him as guides. 



It appears probable that, in certain places at least, the Cuyahoga 

 sediments under cover in southeastern Ohio may be coarser than 

 they have been described. However, it does not appear necessary 

 to assume that the Cuyahoga under cover to the southeastward 

 must be made up of similarly coarse sediments over wide areas. 

 A great deal of coarse material, such as is found in either of these 

 facies, might be transported through a relatively much smaller 

 channel in fine-grained deltal sediments of an earlier stage of accu- 

 mulation. To account for the conditions in this way would 

 probably necessitate the assumption that there was a change in 

 the nature of the material transported toward increasing coarse- 

 ness, aggradation in proportion, and a consequent building out 

 over the subaerial portion of the delta of a sandstone member of 

 some thickness, but this thickness, it appears, would be thin in 

 the lower courses of the delta. 



The Vanceburg sandstone facies. — The Vanceburg facies was 

 accumulated under conditions different from those of the Toboso 

 and Hocking Valley conglomerate facies. Nevertheless, it probably 



