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Cincinnati Society of Natural History. 



tioned constitutes the lower part of the Dayton stone of Ohio, or the 

 Laurel bed of Indiana. Above this are found the cherty layers of the 

 Laurel bed, beginning below with 2 inches of chert, followed by 15 

 inches of good flagging stone, 3 inches of chert, 13 inches of rock, 

 1 inch of chert, 1 foot of rock, and 1 foot of chert, evidently once 

 belonging to different layers, but now all heaped together in con- 

 sequence of the weathering away of the -limestone layers which once 

 separated them. 



b. 1 1 ashanfs quarry occurs about a mile south of Ball's quarry. 

 The flinty beds of the Laurel bed (Dayton stone) are worked here. 

 The rock seems to pass gradually downwards into the Clinton. At 

 least no very satisfactory line of demarkation lithologically could be 

 discovered. The Clinton here, where undoubtedly recognized, is a 

 blue hard siliceous rock, like that at Ball's quarry. Only 4^ feet of 

 Clinton could be identified with certainty. It contained Syringopora 

 (Drymopora) fascicularis, Haly sites catenulatus and Favo sites niagarensis. 



Under the Clinton occured a blue clay layer. Lower down the 

 creek blue siliceous rocks, weathering to red, and similar to the sili- 

 ceous Clinton above, are found. Being below a blue clay bed, they 

 are considered Lower Silurian rocks, but no fossils indicating this 

 horizon were found. The sections between this place and Laurel 

 should be carefully studied. At Laurel the most northern exposures 

 show the Clinton reduced to a thickness of 8 inches. There 

 must be an interesting problem involved here to account for this 

 sudden thinning out of the Clinton in going southwards about 10 

 miles. Moreover the Clinton in this distance has changed lithologic- 

 ally from a hard siliceous fine grained rock at Washam's quarry to a 

 softer, pure limestone, more fossiliferous at the Laurel quarry. The 

 siliceous form of the Clinton is also absent at the Middle Fork 

 exposure north-east of Richmond, at the Elkhorn Falls, and at Fair 

 Haven. The distribution of this siliceous phase of the Clinton is 

 therefore worthy of study. It is evidently a local phase of the Clinton. 



38. Laurel— a. Dry Branch or Geyer's quarry. This quarry is 

 found along the road about two miles north-west' of Laurel. The 

 Clinton here is only 8 inches thick. It is a softer, and less blue rock 

 than the uppermost layer of the Cincinnati group beneath. It has a 

 granular texture and contains a small form of OrtJiis calligramma i of 

 the type found at Hanover, Indiana, also Pachydutya bifurcata, Pachy- 



