THE 



FAUNA OF THE MAXVILLE LIMESTONE. 



William Clifford Morse, 

 ■ Ohio State University. 



INTRODUCTION. 



The present paper represents the final results of a study of 

 the Maxville limestone begun in 1906, the historic, stratigraphic, 

 and economic portions of which are soon to appear as Bulletin 

 13 of the Geological Survey of Ohio. In that publication it 

 was shown that the region of outcrop of the limestone is nat- 

 urally divisible into three parts, a Northern Area, a Central 

 Area, and a Southern Area, and that in the stratum itself, in 

 many places, may be recognized three divisions, a lower zone, a 

 middle (shale-nodular) zone, and an upper zone. The North- 

 ern Area extends from a point near Zanesville on the north 

 to one near Logan on the south, and contains the best exposures 

 of the limestone. The Southern Area reaches from Hamden 

 on the north to the Kentucky side of the Ohio River on the 

 south, and has but a few widely separated exposures. The 

 Central Area lies between the other two and so far as known 

 contains no exposures. The limestone of the lower zone is 

 an impure one, nearly destitute of regular bedding planes, poor 

 in fossils, and about twenty-five feet in thickness. The middle 

 zone is about three feet thick, and consists of alternating nodular- 

 like layers of limestone and thin intervals of shale, both of 

 which are fossiliferous. In the upper zone, the maximum thick- 

 ness of- which is twent3^-two feet, the fossils are common, the 

 limestone purer, and the medium layers are separated by shaly 

 partings in such a manner that the stratification is the conspicu- 

 ous feature. 



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