SUPPLEMENTAL REPORT HANGIJSTG ROCK DISTRICT. 897 



blue. It occasionally resembles certain phases of the Putnam Hill Lime- 

 stone very much, but its distance from this in the scale renders any con- 

 fusion from this cause unnecessary. The only limestone with which it 

 is really likely to be confounded is the Ames Limestone that lies about 

 one hundred feet above it. 



6. The Ames Limestone. — The last of the series is the stratum called 

 the Ames Limestone by Prof. Andrews, from the township of this name 

 in Athens county. It is a light gray, crystalline, highly fossiliferons 

 limestone, often crinoidal, that is found in all of the Coal Measure coun- 

 ties of the State in which it is due. In the district under consideration, 

 however, it is but seldom reached. Its altitude above the Cambridge 

 Limestone, in the Hocking Valley, varies in the few sections measured, 

 between eighty-five and one hundred and twenty-one feet. The interval 

 in two sections in Gallia county was found to be one hundred and forty 

 feet. It is often called the " fossil limestone," or the " crinoidal lime- 

 stone." It will answer an excellent purpose for furnace flux. In this 

 district, at least, it does not pass into flint. 



The Ames Limestone forms the summit of the series to be considered 

 here. 



ACCESSORY SEAMS. 



Between the Ames and the Cambridge Limestones, one of the accessory 

 seams named on a preceding page is due, viz., the Ewing Limestone. It 

 has not been seen where the interval between the limestones named 

 above is shortest, but in the Sunday Creek Valley it is found at about 

 eighty feet above the Cambridge. It does not vary ten feet from this 

 interval throughout the field. It is quite heavily charged with iron, is 

 non-fossiliferous, and weathers easily. It is often found in isolated 

 bowlders in a seam of red earth along the line of outcrop. It is con- 

 cealed by the products of its own decomposition, much more than any 

 other limestone of the series. 



Between the Hanging Rock and Shawnee Limestones, two seams of 

 buff limestone are often found. Neither is steady in occurrence, but the 

 ,' pper one, named the Norris Limestone, marks an important horizon. 

 A valuable ore seam is found at this level in the southern part of the 

 district. The Norris Limestone, in the Hocking Valley, seldom reaches 

 a thickness of two feet. 



The lower of these two seams, called the Snow Fork Limi^stone, is 

 found at comparatively few points. On the Snow Fork of Monday Creek, 

 Hocking county, however, it is shown in numerous outcrops, and has 

 been counted available in that region for possible furnace use. It lies 

 only twenty or thirty feet above the great coal seam of the valley. 



57 



