388 Frank Carney 



unlike in principle. The rock material of the Atlantic coastal 

 plain area was deposited by the streams flowing to the east and 

 southeast, streams which carried sediment into the bordering 

 ocean, whose currents distributed it; when this epi-continental 

 tract was added to the land, the consequent streams also took a 

 south and southeast direction, to which they still hold. The 

 sediment that formed the rocks of much of Ohio was spread by 

 streams, coming probably from a northern source, into a sea that 

 grew deeper to the east and south ; therefore, the natural dip of 

 the rocks resulting from these deposits is towards the south and 

 east. 



Adjustments aynong consequent streams. Not long, geologically, 

 after the region of Ohio was uplifted finally from the sea, or the 

 sea withdrawn from it, the whole area, because of the mountain- 

 making disturbance to the east, was warped. In the east this 

 disturbance continued till the formerly horizontal rock beds 

 were folded into the parallel ridges of the Appalachian mountains ; 

 in Ohio the disturbance is represented by the Allegheny plateau. 

 This dynamic movement progressed very slowly; the rivers 

 underwent adjustments, probably leading much of the original 

 consequent drainage westward into the Mississippi basin, via 

 northern Indiana. 



The drainage pattern that develops in a shift from the conse- 

 quent stream courses depends very largely on the relationship of 

 the rock horizons in which the valleys are being cut. When the 

 formations, which are not horizontal, alternate in hardness, and 

 are transverse to the direction of the stream flow, ridges of resist- 

 ant rock will appear across the area between the rivers, and 

 subsequent streams will develop valleys laterally through the 

 intervening belt of softer rocks; thus, the valley of the major 

 consequent river has a gorge-like form alternating with wide 

 mature reaches, because of the contrasts of hardness in the for- 

 mations. With the lapse of time, and the succession of several 

 incomplete drainage cycles, the ridges will be more and more 

 obliterated. It is probable that the drainage pattern, developed 

 in Ohio after the slow disturbances incident to the folding of 

 the Appalachians, endured for a long time. 



One can only offer suggestions as to the various steps between 

 the original consequent rivers and the establishment of present 

 drainage. Many investigators have studied this problem. Some 



