332 



GEOLOGY OF OHIO. 



The river here flows through a, broad valley of alluvium, containing 

 pebbles, and resting. upon a deep deposit of water-washed gravel. An 

 old deeply excavated channel opens southward at C, the mouth of Big 

 Run, now filled at the surface with sandy material. At A a narrow 

 channel is filled with the original Drift, which has been carried ,away at 

 the surface by recent erosion, but not down to the present water level. 

 The encroachment of the river at this point exposes a clean section of 

 this original deposit, as given below : 



Section of Old Valley DKiifT, Big Eun. 



^S^f^i^^^r^'^Ow^ Yellow clav. with Drift bowlders and pebbles, and many flat fragments of 

 ^M^^.^a^^ local r^ks .•-.. 



Ft. 



8 



Elne bowlder clay nnstratified. with rounded granitic bowlders, gravel, aid 

 angular fragments of glacial roclis 20 



Laminated blue clay 3 



Coarse stratitied gravel 4 



Coarse stratified Band 2 



Yellow laminated clayr. 2 



Blue laminated clay 2 



Unstratiiied bowlder clay 4 



stratified sand and gravel 8 



At Mt. Vernon, wells sunk in the alluvium pass only through sand 

 and gravel. Those on the sandy slopes strike — 



Ft. 



1. Yellowclay 10 to 15 



2. Blueclay 30 to 40 



3. Gravel, sand, and broken stone to bed rock. 



That part of the county east of the Baltimore and Ohio Railroad and 

 north of the Cleveland, Mt. Vernon and Columbus Railroad, consisted 

 originally of a high undulating table land, covered with glacial Drift. 

 Erosion has intersected it with harrow ravines, and filled it with small 

 streams, leaving a succession of well-rounded hills of very graceful out- 

 line, characteristic of the Waverly in this part of the State. This pecu- 

 1 iarity is only modified by outcrops of the Waverly Conglomerate. Where 

 this is wanting, or is below the bottoms of the valleys, the hills are en- 

 tirely without benches; the lines of the landscape are all graceful curves; 



