April, 1909.] Conemaugh Formation in Southern Ohio. 485 



a formation be permissible, then the term Patriot would be very 

 appropriate for the limestone also, and is proposed. The coal is 

 persistent across entire counties with a thickness of about 18 

 inches. At several points along Leading Creek in Rutland 

 Township, Meigs County, a workable thickness is found. 



The "First Cow Run" sandstone is massive and coarse- 

 grained and contains conglomerate zones. At Burlington, in 

 southern Lawrence County, the river bluffs show an exposure of 

 over 60 feet. This is unusually thick, an average being about 

 25 feet. 



The Cambridge limestone lies from 240 to 300 feet below the 

 Pittsburg coal and from 90 to 145 feet below the Ames limestone. 

 In tvpical outcrops it is a gray rock forming a single bed about 

 28 inches thick. The stone is very hard and when struck gives a 

 metallic ring. In places there is a double structure consisting of 

 two beds of limestone interlain by several feet of shale containing 

 a thin coal. Toward the south both beds are often cherty. 



Below the Cambridge, a thin coal is often found. This is 

 especially true in the southern coimties. Here it sometimes 

 reaches a thickness of 3 feet. 



The Brush Creek or No. Vila coal is of little importance in 

 southern Ohio. It is usually represented by little more than a 

 blossom. 



The Mahoning sandstone is frequently shaly and does not 

 hhow the persistent characteristics of the same horizon in 

 Pennsylvania. 



Economic Features. 



The few coal seams of the Conemaugh are too thin to be 

 worked except in a very small way. Occasional^ a local thicken- 

 ing gives a deposit which is stripped by the farmers for home use. 

 Of these thin coal seams, the Patriot is probably the most 

 persistent. 



Limestone and iron ore deposits are very scant. Nowhere is 

 there a limestone thick enough to play any part in the cement 

 industry. The few thin outcrops are stripped by the farmers for 

 use on the roads. The Ames and Cambridge are well suited for 

 this purpose, being very hard and durable. The clays contain 

 numerous zones of hematite nodules, but the deposits are too 

 thin and scattered to be of any importance. 



Beautiful laminated sandstones are not unknown in the 

 formation but most of these are too friable for building purposes. 

 Some of the more resistant rock is used for bridge abutments and 

 foundations. 



Most of the Conemaugh belt is not well adapted to agricul- 

 tural pvirposes. The topography is very broken especially in the 

 counties bordering on the Ohio River. The more resistant sand- 

 stone layers form abrupt ledges, while the thick beds of soft shale 



