CHAPTER LXX. 



REPORT ON THE GEOLOGY OF WARREN COUNTY. 



BY EDWARD ORTON, ASSISTANT GEOLOGIST. 



Warren county is bounded on the north by Montgomery and Greene, 

 on the east by Clermont, on the south by Clermont and Hamilton, and 

 on the west by Butler. The Little Miami River, which crosses it diag- 

 onally in a south-westerly direction, divides it into two nearly equal di- 

 visions. Its western side slopes towards the valley of the Great Miami, 

 and reaches this valley in its north-western corner. 



Prom these statements, it can be readily understood that the surface 

 of the county consists of two main divisions of the table-land that con- 

 stitutes south-western Ohio — one of them lying between the two rivers, 

 and forming a water-shed — the other making the beginning of the flat- 

 lying tract that stretches away to the east and south, which has been 

 noticed in previous reports. 



The northern range of townships is traversed by the deep and com- 

 paratively narrow gorge of Clear Creek, the east and west direction of 

 which is unusual in the tributaries of the Miami. 



Turtle Creek and Union townships furnish striking examples of the 

 waste that the country has suffered from erosion of an earlier day. A 

 broad channel, at present occupied by Muddy Creek and Dick's Creek, 

 connects the valleys of the two Miamis through this district. The old 

 branch of the Miami Valley Canal, from Lebanon to Middletown, followed 

 this ancient channel, connecting the two points named above, without 

 intermediate lockage. It is certain that by means of this channel the 

 two rivers were formerly united, at least there are no rocky barriers to 

 divide them, T&ither the Little Miami holding the westerly direction, 

 which it now has, from Morrow to Deerfield, or, as is more probable, the 

 valley of the Great Miami being opened out by glacial erosion to the 

 south-east, the direction, indeed, in which glacial action has been most 

 conspicuously exerted in south-western Ohio. 



The main valley of Turtle Creek furnishes another example of erosion 

 which the present conditions do not fully account for. The stream no 

 where runs upon a rocky bed, and to the north-eastward it furnishes an 

 almost, if not quite, uninterrupted channel from the valley of the Little 



