346 The Ohio Naturalist. [Vol. XIV, No. 8, 



Where was the land from which these pebbles came? One 

 would be inclined to answer at once, from the west and north 

 where older rocks now occur. But this leaves a structural feature 

 observed in both conglomerates rather hard to explain. At dif- 

 ferent points south-east of Wooster, the upper conglomerate is 

 found to be cross bedded with bedding planes dipping sharply 

 toward the north. In the northwestern part of the Massillon, 

 the southwestern part of the Akron, and the eastern part of the 

 Medina quadrangles, the lower conglomerate shows conspicuous 

 crossbedding, either toward the west or toward the north. It is 

 hard to see how this structure can occur in any other way than 

 dipping away from a shore, whether produced by stream current 

 or undertow from waves. If one would assign the structure in 

 this case to northward flowing currents along shore, another 

 difficulty is met. In the last named region where twenty to thirty 

 feet of the conglomerate is exposed in one outcrop, various levels 

 of crossbedding occur in different directions varying from west 

 to north. This would seem to be more like a delta deposit of a 

 stream flowing from the southeast. No case of crossbedding has 

 been found which would indicate that the shore was to the west 

 or north, but rather to the south and east. If the interpretation 

 of this structure be correct, it points to the presence of a land 

 mass where we have thought there was open sea. 



The existence of these unconformities in middle Mississippian 

 rock would seem to throw light on the time of the very numerous 

 small folds found in the Medina quadrangle and only less numerous 

 in a number of other quadrangles eastward to the Pennsylvania 

 state line. They rarely occur where the Pennsylvanian is exposed 

 above, hence the uncertainty of assigning them to that age or 

 later. Some of them very lilcely belong to post Mississippian 

 time, but it should be stated that so far as observed they are much 

 less numerous in the Pennsylvanian than in the Mississippian and 

 particularly in the Mississippian below the conglomerate horizons. 

 One very clear case occurs in an outcrop in the north-cast comer 

 of the Medina quadrangle in a ravine one-half niilc southwest 

 of Hinckley village, where the horizontal beds of the Sharon 

 conglomerate (base of Pennsylvanian) rest upon the upturned 

 edges of the Mississippian. The top of the latter here is about 430 

 feet above top of the Berea, or more than 150 feet below the hori- 

 zon of the lower conglomerate. The contact is sharp and the 

 layers of shale are inclined about twenty-fi\-c degrees. 



If these conglomerates described above are the same beds 

 found in the central part of the state and southward, which would 

 appear to be true, it implies the presence of associated uncon- 

 formities wherever they occur. 



