DELAWAKE COUNTY. 289 



No. 22. Limestone in thin or slaty beds, so contorted and yet ag- 

 glomerated by chert (which forms nearly one-half of the 

 mass) that the whole seems massive ; the chert is dark.. 3 ft. 6 in. 



" 23. Beds of blue limestone of four to ten inches, alternating 

 with chert beds of one to four inches ; these limestone 

 layers weather into beds of one to two inches 4 " 



" 24. Thin slaty beds, with alternating chert beds, the latter 

 about an inch thick; where this number forms the bed 

 of. the creek it does not appear slaty, but massive and 

 smooth, like a very promising building stone ; the .creek, 

 where it enters the river bottoms, is on this number, 

 and nothing more is seen 6 " 



Total. 



These limestone beds have been quarried for the building of Mr. 

 Bartholomew's residence. They are none of them conspicuously fossil- 

 iferous. 



Hamilton and Upper Coniferous. — These names are here associated, be- 

 cause whatever Hamilton fossils have been found in the county have 

 been detected in that formation that has been described in reports on 

 other counties as Upper Corniferous, and because it seems impossible to 

 set any limit to the downward extension of the Hamilton, unless the 

 whole of the blue limestone be Hamilton. The shale which has been 

 described as Olentangy shale was at one time regarded as the only equiv- 

 alent of the Hamilton, from the occurrence of Hiiiiilton fossils in a shaly 

 outcrop at Prout's Station, in Erie county. But after the survey'of the 

 county revealed no fossils in that shale, it became evident that it could 

 not be the equivalent of the very fossiliferous outcrop at Prout's Station, 

 and should not bear the name of Hamilton. That shale partakes much 

 more largely of the nature of the Huron than cf the Hamilton. The 

 name Corniferous is made by Dr. Newberry to cover the whole interval 

 between the Oriskany and that shale, the Hamilton being regarded as 

 running out into the Corniferous, its fossils mingling with typical Corn- 

 iferous fossils. In the State of Michigan, however, the term Hamilton 

 has been freely applied to these beds, the Corniferous, if either, being 

 regarded as reduced. The lithological characters of the Michigan Ham- 

 ilton are the same as those of the Upper Corniferous in Ohio, and it is 

 hardly susceptible of doubt that they are stratigraphically identical. In 

 Ohio there is a very noticeable lower horizon that should limit the Ham- 

 ilton, if that name be applicable to these beds, and if palseontological 

 evidence will not limit it.* 



* A few words of explanation are necessary in connection with the remarks of 

 Prof. Winchell, which follow : 

 1st. The shale bed, which is described above u:..ler the name of Olentangy shale, 

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