THE N I AG ARAN FORMATIONS OF WESTERN OHIO 363 



Thickness 



Total 

 Thickness 

 No. Feet Inches Feet Inches 



17. Thicker layers of compact limestone, light gray 



to buff, when weathered, with shaly partings. 



The majority of the layers are perhaps 3 to 5 



inches in thickness; but there are thicker ones 



which apparently range from 8 to 14 inches. 



No chert was noticed in this zone 5 3 47 5 



16. ?Top of Osgood beds. — Buff, compact, 8-inch 



layer at top of ledge on south side of falls, which 



is apparently the one across the quarry road in 



the base of the old quarry at the spring. The 



top of this layer is apparently the horizon where 



Dr. Foerste has drawn the line of separation be- 

 tween the Osgood beds and Laurel limestone. 



Lithologic characters, however, in the vicinity 



of Laurel would apparently favor classing it 



with the Laurel limestone 8 42 2 



15. Blue, argillaceous, soft shale or clay. This is 



the blue-clay stratum of Dr. Foerste. 1 6 41 6 



14. Shaly, light-gray limestone 4 40 o 



13. Light-gray, compact, even-bedded limestone; 



some of the bedding planes rather rough. The 



layers vary in thickness from 5 to 9 inches, and 



perhaps the majority of them average about 8 



inches. This is the Lower Quarry or Osgood 



rock of Dr. Foerste, and is apparently the con- 

 tinuation of the Dayton limestone in Indiana 64 39 8 

 12. Brassfield limestone. — Light-gray, crystalline 



limestone. Apparently the upper foot and 3 



inches of this zone was regarded by Dr. Foerste 



as a "doubtful horizon: White Clinton or base 



of Niagara rock " 2 3 33 4 



11. Crystalline gray to pinkish limestone. It is 



very irregularly bedded and contains pyrite, so 



that it is frequently rusty colored on the 



weathered surface. Dr. Foerste's section re- 

 ports "Clinton; 7 feet 6 inches; reddish".... 67 31 1 

 10. Richmond formation. — Light-gray, impure lime- 

 stone with portions that are darker colored. ..16 24 6 

 9. Gray, impure limestone, the upper layer a foot 



thick separated by a shaly parting from a lower 



layer of similar limestone, 1 foot 3 inches thick 23 23 o 



