774 JESSE E. HYDE 



the Scioto shale facies and which have been considered the upper 

 part of the Portsmouth member of the Cuyahoga. This tendency 

 on the part of the Byer sediments suggests strongly that its material 

 was also derived from the eastward and southward, in spite of the 

 thinning of the formation to the eastward. 



It is not possible to say to what extent the member continues 

 to thicken westward because of the disappearance of the Allensville 

 member in that direction just where the Byer passes into shales 

 and sandstones which are lithologically so similar to those of the 

 Vinton member as to be indistinguishable from them. 



The Byer member was formed during a period of quiet sedimen- 

 tation. The shoreline lay far enough to the eastward so that the 

 outcrop belt of central and southern Ohio was wholly outside the 

 zone of continual shifting of sands by currents and waves, and 

 beyond the reach of delta or sand-spit accumulations such as are 

 seen in the Cuyahoga. Sharp contacts between beds are seldom 

 observed where shaly sandstones make up a considerable part of 

 the succession, the change from sandstone beds through shaly 

 sandstones to shale beds being almost always a gradational one. 

 Well-defined bedding-planes are more likely to be found in those 

 portions made up almost entirely of sandstones and where the 

 material is slightly coarser, as in central Ohio. Although the con- 

 ditions of sedimentation are best described as quiet, the abundant 

 sediment making up the member was probably swept to its present 

 position and distributed largely by gentle current-action and not 

 by subsidence from mechanical suspension in the water. The 

 material is too coarse to be carried any distance in that way. 

 The presence of such gentle current-action is shown, for example, 

 (i) by frequent cross-bedding in the finest material with long, 

 gently sweeping stratification planes, and (2) by the local sweeping 

 together into a heap of such an odd aggregation of species and 

 abundance of individuals as was found in three cubic feet in a cer- 

 tain bed at Sciotoville, which is otherwise practically barren of 

 fossils, although excellently shown for half a mile and 30 feet thick. 



If the correlations made by Cooper in sections to the northward 

 be accepted, the Byer member continues little changed and from 

 25 to 40 feet thick for at least 55 or 60 miles to the northward of 



