330 



GEOLOGY OF OHIO. 



side of the railroad from Mt. Vernon to the south line of the county, 

 marked by successive terrraces, and from one to three miles wide. It is 

 bordered by hills of modified Drift, and forms an extension northward 

 of the valley in which Owl Creek flows, until deflected to the east by 

 Mt. Vernon. 



The following profile, reaching from Mt. Vernon to Martinsburg, 

 omitting many of the less important hills and valleys, will show the 

 character of the Drift deposits in this part of the county : 



Profhb Section feom Mt. Vernon to Maetinsbdbg. 



The slope of the first hill, which rises to one hundred and seventy 

 feet above Mt. Vernon, exhibits the olive shales of the Waverly covered 

 by Waverly debris, with no evidences of Drift except occasional granite 

 bowlders. On the top of this hill are found thin bowlder clay and granitic 

 pebbles. Ascending the next slope to the height of three hundred and 

 ten feet, the outcrop and debris of the Waverly continues, with no Drift 

 material until passing about twenty feet downward on the south-east 

 side. There granite bowlders are found, and the slope below is covered 

 with Drift mingled with angular fragments of the local rocks. The 

 Drift continues to the top of the next hill, two hundred and eighty-five 

 feet, but is thin, and the soil is composed mainly of local debris. One 

 mile north of the last are broad expanses of gently undulating sandy 

 fields, exhibiting no evidence of Drift except large scattered bowlders of 

 granite, the soil like the banks of sandy streams. Rising above these 

 sandy billows are irregular ridges of clay composed largely of foreign 

 Drift. At the highest elevation — three hundred and five feet — the hill 

 is capped with a heavy deposit of clay Drift. On the descending slope, 

 at twenty feet from the top, a sandy water-washed surface is reached 

 with granitic boulders scattered over it. Descending toward the eastern 

 valley, the Drift on the slopes is deeper. On the last slope, at an eleva- 

 tion of two hundred and seventy-five feet, the Drift disappears, and the 

 crushed layers of the Waverly are covered only with their own debris. 

 At two hundred and fifteen feet the river Drift of washed sand, gravel, 

 and granitic boulders is reached, which passes into the alluvium of the 

 valley, cut by Big Run at an elevation of one hundred and sixty-five feet 

 above Mt. Vernon. Ascending the divide on the opposite side of the 

 stream, the same series of materials is found in reverse order, viz. : 



