THE RELATIONSHIPS OF THE OLENTANGY SHALE 

 AND ASSOCIATED DEVONIAN DEPOSITS 

 OK NORTHERN OHIO 1 



C. R. STAUFFER 



The University of Minnesota 



In the flat glaciated region to the south and east of Sandusky 

 there are few outcrops of the older rocks. The drainage is mostly 

 by small, weak streams which have not yet had time to erode exten- 

 sive valleys, and railroads have not been compelled to cut deeply 

 in order to establish their grades. About seven miles south of 

 Sandusky, however, whore the land is a little higher than in the 

 city and the mantle rock is exceedingly thin, some of the creeks 

 have exposed small sections of bedrock which are somewhat 

 exaggerated by a considerable local dip. Two of the more impor- 

 tant of these are to be found along Plum and Pipe creeks. These 

 sections have been discussed elsewhere,-' but a recent study of the 

 region has added some valuable facts to those formerly given and 

 has made it possible to correlate this Ohio Hamilton with the 

 Devonian deposits of the same age to the north of Lake Erie. 



Plum Creek heads about nine miles southeast of Sandusky and 

 flows, in a general northerly direction, to the lake. At a point 

 about two miles east-northeast of Prout station, on the Baltimore 

 & Ohio Railroad, it cuts into Huron shale, and a little farther north 

 into the Hamilton beds, exposing the following section: 



Section of the Hamilton rocks and Huron shale along Plum Creek 



Thickness 

 Huron Shale Ft. In. 



12. Shale, bituminous, black 4 o 



Widder Beds 



11. Prout or Encrinal limestone. A very hard siliceous blue lime- 

 stone containing a little chert and much pyrite. Silicitied corals 

 and crinoid stems are abundant, the latter especially in the 

 middle layers S 10 



1 Published with the permission of the Deputy Minister of Mines, Ottawa, 

 Canada. 



2 Geological Survey of Ohio, Bulletin No. 10, 4th Scries, 1909, pp. ng-22, Pis. YIII 

 and IX. 



470 



