CHAPTER LXXIITI. 
REPORT OF THE GEOLOGY OF MADISON COUNTY. 
BY EDWARD ORTON, ASSISFANET GEOLOGIST 
Madison county is bounded on the north by Union, on the east by 
Franklin and Pickaway, on the south by Fayette, and on the west by 
Greene, Clarke, and Champaign counties. 
Its surface is comparatively level. Its lowest land is found in the 
south-eastern corner, near Mount Sterling, in the valley of Deer Creek. 
its highest land lies to the west and north-west of London, and is about 
1,100 feet above the level of the sea. The range of the county does not 
probably exceed 300 feet. The altitudes of a few of the principal points 
in the county are subjoined :. 
London, 1,010 feet above tide- water. 
West Jefferson, 880 feet above tide- water. 
Mount Sterling, 865 ‘ ny 
Midway, 950 re ie 
South Solon, Wo eg 
County Infirmary 1,100 feet above tide-water. 
County line on Xenia pike, west of London, 1,100 feet above tide-water- 
Ohlinger’s Hill, west of Summerford, 1,100 oe s 
Of these altitudes, all but the first were obtained by the barometer, ang 
must be taken as approximations only. They suffice to show, however, 
the very great degree of uniformity that prevails in the surface of the 
county. <A. very large part of its area lies at altitudes varying between 
950 feet and 1,050 feet above the sea. Nothwithstanding this uniformity 
of level, there is but very Httle swamp-land in Madison county. The 
slopes, though very gradual, are so distributed that the water always 
knows which way to go. Between those sources of Little Darby Creek 
that lies within the county, and the point where the creek crosses the 
county-line, there is a fall of scarcely less than 200feet. The distance is 
about 15 miles and the average descent is between 13 feet and 14 feet to 
the mile. 
Deer Creek descends, from its head-springs near Summerford, 300 feet, 
in its diagonal course of 20 miles across the county—-an average fall of 
15 feet to the mile. 
