STATE GEOLOGIST. ate, 93 
below the surface, around the village Berea, in Cuyahoga county, is un- 
distinguishable from that obtained at a depth of more than 2,000 feet in 
Washington county. Sometimes, though not usually, the formation 
divides, a bed of shale lying between two of sandstone; at other places 
the upper portion of the formation consists of sandstone and the lower 
of shales. In thickness the formation varies from 50 feet or more in 
the northern part of the state to a half dozen or less in the southeastern 
portion, and occasionally disappears entirely, its place being occupied by 
shales. The Berea grit is succeeded above by the Berea (Sunbury) and 
Cuyahoga shales, having usually an aggregate thickness of from 500 to 
600 feet, and below by the Ohio shales, having a great and rapidly in- 
creasing thickness eastward. The most remarkable character of the 
formation, however, remains to be mentioned, viz., its persistence. From 
its outcrop it has been followed by the drill from county to county, and 
often from section to section, until the eastern and southeastern limit 
of the state is reached. It is as easily recognized below drainage as 
above, and this character makes it a stratigraphical landmark of great 
value to both driller and geologist. In many counties in the eastern 
part of the state, especially those fronting on the river, numerous efforts 
have been made to find a productive sand below the Berea, but in every 
case this effort has been unsuccessful. It may now be taken as having 
been demonstrated by the drill that when the Berea sand has been passed 
in this territory the last hope of oil or gas has gone. 
While a trace of oil or gas has perhaps been found in every county 
where the formation exists, the production in commercial quantities is 
limited to Lorain, Medina, Trumbull, Columbiana, Stark, Jefferson 
Harrison, Belmont, Guernsey, Monroe, Noble, Vinton, Perry, Athens, 
Morgan and Washington counties. 
The Logan Group.—The relative position of this group and the 
Berea is shown by the following skeleton record of a well on the Mead 
farm, in the Elk Run Pool, Washington county. 
Feet. 
Salt sand top at ne 200 
: bottom at 1,280 
Pottsville conglomerate { 
bivtaetoneaanay oo. {top at eae 
L ( bottom at: —‘ 1,500 
Maxville limestone ....... Mountain limestone 
(“Big lime”) .... top at 1,510 
bottom at 1,545 
melcocaneeroup <0 4.5. en. <. Big Injun series.... top at 1,560 
bottom at 1,730 
Beene erita mene eer nna eae ee ES top at 2,124 
bottom at 2,138 
