THE NIAGARAN FORMATIONS OF WESTERN OHIO 359 



No. 



Thickness 

 Feet Inches 



Total 



Thickness 



Feet Inches 



of Brassfield limestone was measured; but it 

 extends on down the creek and a quarryman 

 stated that about 8 feet is shown along the 

 creek 8 ± o 8 o 



A view of the southern wall of the Lewisburg Stone Co. quarry 

 is shown in Fig. 2. The lower part of the wall is the Laurel even- 

 bedded limestone, the top of which Mr. Cottingham is indicating 

 by the hammer, above which is the conspicuous "mottled zone," 

 and above this zone is the Springfield dolomite: 



In the foregoing section the Laurel limestone is called the "blue 

 building stone" by the quarrymen and comprises Zones 12 and 13 

 with a thickness of about 10 feet 2 inches. A section at a different 

 part of the southern quarry wall gave a thickness of 9 feet 10 

 inches. It is well shown in the picture of the southern wall of this 

 quarry (Fig. 2) where Mr. Cottingham is marking its top with the 

 hammer. Samples of the Laurel limestone from the southern wall 

 of this quarry were analyzed by Professor Demorest with the 

 following result: 



The massive "mottled zone," with a thickness of 4 feet 1 inch, 

 immediately above the Laurel limestone, is also well shown in 

 Fig. 2. Samples from this zone in the southern wall of the quarry 

 were also analyzed by Professor Demorest with the following 

 result : 



The following analysis by Professor Demorest of samples of 

 the West Union limestone from Sproull Ravine, about if miles 



