24 GEOLOGY OF OHIO. V 



SECTION OF EKIE CLAY. 



1. Delta sand, clay, and gravel 2E > ft- 



2. Laminated clay above lake level 75 ft. 



3. Blue clay below lake level 75 ft - 



4. Coarse sand 1 & - 6 in - 



5. Blue clay 27 ft - 



6. Quicksand 10 in - 



7. Blue clay 29 ft - 2 j n - 



8. Quicksand lit 6 in - 



9. Blue clay 2 ft - 6 in - 



10. Quicksand 1 ft. 6 in. 



11. Blue clay 30 ft- 



12. Fine gravel 5 ft. 



13. Blue clay .'. 29 ft. 



14. Coarse gravel, with much gas 3 ft. 



15. Fine quicksand 1 ft- 



16. Blueclay 5 ft - 



17. Coarse gravel 2 ft. 6 in. 



18. Clay to shale rock 8 ft- 6 in. 



On the lake-shore, a mile distant from this locality, a carbonaceous 

 stratum, with many logs of coniferous trees, lies on the surface of the 

 Erie clay, and separates this from the Delta sand deposit above. 



An analysis made by Prof. Wormley of an air-dried specimen of the 

 laminated portion of the Erie clay from this locality gave the following 

 results : 



Water 4.00 



Silicic acid 59.70 



Alumina 14.80 



Iron, sesquioxide 4.60 



Lime, carbonate 8.90 



Magnesia 5.14 



Fixed alkalies 3.40 



100.54 

 Along the summit of the watershed the Erie clay is less distinctly 

 shown than in most other parts of the State. Many patches of it 

 remain, however, and it would seem to have been once much more 

 widely spread than now. From this region it has unquestionably been 

 generally washed away by the drainage from the glacier when it filled 

 the lake-basin and terminated at its southern rim; and subsequently, 

 when this rim was a chain of islands, washed — and in some instances 

 swept over — by the waves of our great inland sea, the clay was still 

 further removed, and kames and sand banks left in its place. In the 

 southern portion of the glaciated area, the Erie clay is pretty con- 



