486 The Ohio Naturalist. [Vol. IX, No. 6, 



are easily cut through by the streams. As a result there are 

 numerous gorge-like valleys with narrow flood plains. The steep 

 shale hills are much given to landslides. This unstable state of 

 affairs makes much of the country of little use except for grazing 

 purposes. 



Although the preceding statements would seem to indicate 

 that the Conemaugh is "barren" as its old name suggests, still 

 there are certain redeeming features. The area was once covered 

 with valuable forests and could be reforested. In addition it 

 contains an inexhaustible supply of clay shale and is also an oil 

 producer. 



Formerly the region was clothed with unbroken forests of 

 oak, tulip, walnut and other valuable timber. Very little of 

 this former growth remains. In its place one finds large tracts 

 of land overgrown with sumach, sassafras and blackberry 

 bushes. It is a question whether it would not be well to convert 

 such land into a forest reserve. 



There is an unending supply of shale suitable for the manu- 

 facture of the rougher wares. At Athens, the shale of the Ames 

 horizon is utilized in the making of an excellent grade of paving 

 brick. At a few points, the clay below the Pittsburg coal 

 becomes of economic importance, but at present it is not devel- 

 oped in the southern part of the state. 



Two sandstone horizons have been demonstrated to be oil 

 reservoirs, namely the massive sandstone with a base 90 feet 

 below the Pittsburg coal and the "First Cow Run" sandstone 

 lying above the Cambridge limestone. The former is not of 

 great importance. A few pay wells in it have been put down 

 near Marietta. The "First Cow Run" sand serves as a reservoir 

 for the Chesterhill field^^ located in the adjoining corners of 

 Athens, Morgan and Washington Counties. This field is ranked 

 among the important oil territories of the state. It has been a 

 producer since 1860. A narrow oil belt extends eastward from 

 the Chesterhill field to the Ohio River in the vicinity of Marietta. 



The Cambridge and Ames Limestones. 



The Cambridge and Ames limestones are valuable guides to 

 the geologist, lying as they do in a section made up of a feature- 

 less monotony of shales and sandstone. There are certain 

 lithological peculiarities about the two limestones by which one 

 may be distinguished from the other by a person familiar with 

 the two. 



In addition to the lithological peculiarities it is probable that 

 a study of the fauna of each horizon will reveal more striking dif- 

 ferences. Although the writer has collected material from only a 

 few places, yet a study of these fossils seems to warrant this 

 inference. 



Collecting was done in the Cambridge at Northup, Gallia 

 County and at Langsville, Meigs County, twenty miles to the 



11. Geol. Suiv. Ohio, 4tli Ser., Bull. I, pp. 126-i;j9. 



