670 JESSE E. HYDE 



margin it has a length of 45 or 50 miles, its maximum width is about 

 20 miles. In the southeastern and eastern portions only the upper 

 beds are exposed; in the western and northwestern portions only 

 the lower part remains. The entire thickness is not exhibited in 

 any one section. However, well-records have been easily obtained 

 from the Sugar Grove gas field which extends across it, and have 

 been of much service in unraveling the structure, although little 

 more than generalized impressions can be obtained from the reports 

 coming from the heavy drills there used. 



The sandstones of this province are developed along a very 

 distinct axis which trends north-northwest, south-southeast. 

 Along this line of maximum sandstone development, the thickness 

 is 625 feet, decidedly greater than in the Granville shale province 

 to the eastward, and more than twice as thick as it is some miles 

 to the southwestward in the Scioto Valley shale facies where it is 

 about 295 feet. This increased thickness is due to the increased 

 amount of coarse material. 



Four members are recognized in the Cuyahoga of this area. 



The Lithopolis member is best exposed in the northwestern part 

 of Fairfield County in the vicinity of Lithopolis. The name is 

 newly proposed. It is a series of thin, horizontal, interbedded 

 sandstones and shales. The fact that they are horizontal is to 

 be emphasized. The sandstones are usually light gray or bluish 

 in color, moderately fine grained, and evenly bedded. The beds 

 are usually several inches and sometimes two or three feet thick. 

 The shales are argillaceous, and usually, but not always, somewhat 

 sandy; they are commonly gray in color. Carbonaceous material 

 may be present at times sufficient to darken the gray. The sand- 

 stones and shales, on the whole, are about equal in amount, although 

 at various horizons one may dominate the other and the sandstones 

 appear to be considerably in excess in the upper part. 



The thickness varies from 118 feet to at least 140 feet and 

 possibly 180 or 200 feet between Lithopolis and Chestnut Ridge 

 two miles to the eastward. It is overlain at these localities by a 

 massive coarse, yellow sandstone which is wholly different from 

 those of the Lithopolis member. To the southward, beneath the 

 central portion of the Hocking Valley province, the Lithopolis 



