30 ANNUAL REPORT 
The Mitchell Sand.—This‘is the source of a small oil field a few miles 
east of Marietta. The sand is comparable in thickness with the First 
Cow Run, but in texture is less conglomeritic. As has been shown, it 
lies about 90 feet below the Pittsburg coal, or 200 feet above the First Cow 
Run sand. Its place is near the summit of the Conemaugh formation. 
Wells in this sand commonly begin with a relatively large production, but 
decrease very rapidly. 
The Goose Run Sand.—The formation known by this name has sup- 
plied a score or more small wells near Marietta. The sand is patchy, and 
the life of the wells very short. In fact, the rock is of little value, and is 
recognized here simply to make the record complete stratigraphically. 
Lying nearly 200 feet above the Mitchell, the sand belongs 100 feet above 
the Pittsburg coal, or, in other words, near the middle of the Monogahela 
formation. 
The following table shows the great divisions of the Coal-measures 
proper in Ohio, and also the approximate positions, at least, in these of the 
several sands just discussed: 
Dunkard Formation, or Upper ‘ 
No oil or gas rocks. 
Barren Coal-measures, 500 feet. 
Monongahela Formation, or Goose Run sand. 
Upper Productive Coal-measures, 100 feet (interval). 
200 feet. Pittsburg or No. 8 coal. 
90 feet (interval). 
Mitchell sand. 
200 feet (interval). 
First Cow Run sand. 
Cambridge limestone. 
Mahoning sandstone. 
Conemaugh formation, or 
Lower Barren Coal-measures, 500 
feet. 
Upper Freeport or No. 7 coal. 
Dunkard or 3800-foot sand—:? 
Freeport sandstone. 
50 feet (interval). 
Allegheny Formation, or Lower 
Productive Coal-measures, 250 
feet. 
Macksburg 500-foot sand—? 
Tionesta sandstone. 
70 feet (interval). 
Second Cow Run sand=? Mas: 
sillon sandstone. 
Sharon or No. 1 coal. 
Conglomerate Coal-measures, 
250 feet. 
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