340 GEOLOOT OF OHIO. 



evident that the latter, which is a conspicuous and well marked deposit 

 in all the northeastern counties of the State, thins out in this direction, 

 and like the Carboniferous Conglomerate, it was a shore deposit, the 

 coarse materials being carried no great distance into the deep waters 

 which then lay to the south. At the depth of about six hundred and 

 seventy feet below the Sub-carboniferous conglomerate is the red or choco- 

 late shale, the lowest member of the Waverly, and the first in this 

 county which can be identified fully with any of the subdivisions that 

 are so clearly defined in the valley of the Cuyahoga. This is apj)arently 

 the equivalent of the Bedford shale, which in many places at the north 

 is all or in part red shale. In Erie county this red shale reaches a thick- 

 ness of some forty feet. The well-borings here show that it is very homo- 

 geneous in structure, except that near the bottom there are interstrati- 

 fied bands of argillaceous shale. 



Below this chocolate shale are the Erie shales, which so far as their 

 character can be determined by an inspection of the borings, present 

 precisely the same characteristics as in the northwestern counties, where 

 they are fully exposed. They consist of a mass of soft, blue argillaceous 

 shale, with hard calcareo-silicious bands. 



Below this Erie lies the Huron or " Black shale," the thickness of 

 which cannot be determined. It seems evident that along the western 

 margin of the Sub-carboniferous rocks the lower members of this series 

 and the upper member of the Devonian are thinning out, and that their 

 advance further west is not altogether the result of erosion, but that 

 their extent in that direction was limited by the presence of dry land 

 at the time of their deposit. 



Petroleum and Gas. — The report upon this county would be incomplete 

 without an acknowledgment of the very important aid derived from the 

 borings for oil on Owl Creek, and a brief account of this interesting 

 work. Some ten years ago the attention of enterprising parties was 

 called to the "oil signs" of the eastern part of Knox county. On the 

 western margin of the coal field were indications of dislocation in the 

 rock strata; gas springs were abundant, and from several places it is 

 reported that oil in small quantities was obtained. A company was or- 

 ganized, territory leased, and since that time something like $85,000 has 

 been expended in explorations, mainly under the superintendence of 

 Peter Neflf, Esq., of Gambler. The registers of the wells, which have 

 been kept with commendable care by Mr. Neff, show that there is a 

 marked disturbance in the strata extending to the lower rocks reached, 

 its apparent extent, however, being exaggerated by the causes mentioned 

 on a preceding page. 



