364 CHARLES S. PROSSER 



No. Feet [nches Feet Inches 



8. One layer of gray, massive, impure limestone. 



No fossils soon 4 o 20 9 



7. Layer similar to one above 2 2 16 9 



0. Massive, light-gray layer with dark-gray spots. 



No fossils noted 3 o 14 7 



5, Shale parting 1 11 7 



4. Grayish, somewhat crystalline, limestone which 



tends to split into thinner layers 9 ii 6 



3. Bluish shales alternating with gray, fossilifer- ■ 



OUS limestone 2 3 10 9 



:. Grayish, somewhat crystalline, limestone, hard 



and very fossiliferous 5 4 S 6 



1. Grayish to bluish shales which are not very 



fossiliferous. Foot of falls 3 2 3 



In the foregoing section Zones 11 and 12. with a thickness of 

 8 feet 10 inches, have been classed together and considered the 

 western continuation of the Hrasstield limestone of Ohio. Zones [3 

 and 14 oi light-gray limestone with a thickness of 6 feet 8 inches 

 are considered the western continuation of the Dayton limestone 

 of Ohio. Dr. Foerste has stated that "in Ohio Pentamerus oblongus 

 occurs in the Dayton limestone, equivalent to the base of the 

 Osgood bed.'' 1 The soft blue shale or clay of Zone 15 is believed 

 to correspond to the blue shale of Zone n in the Lewisburg Stone 

 Co. quarry and the shale at the same horizon in the various quarries 

 along the Stillwater River. As stated above in the description of 

 the section, the lithologic break occurs at the top of this shale. 

 which appears to the writer from the sections which he has studied 

 to be the horizon where he would draw the line of division between 

 the Osgood beds and Laurel limestone. If the 8-inch layer of 

 compact, buff limestone (No. 16) immediately above the soft blue 

 shale zone be classed with the Laurel limestone, then 10^ feet of 

 it are shown in the wall of the old quarry on the bank above and 

 south of the falls. It is believed to be the eastern continuation 

 of this limestone which makes Zones 1: and 13 with a thickness 

 of 10 feet j inches in the Lewisburg Stone Co. quarry and the 

 rican Jour. 5 nee, 4th Ser., XVH1 (1904), 341. 



