564 F. G. CLAPP CLASSIFICATrON OF PETROLEUM AND GAS FIELDS 



EXPLANATIONS 



• Oil Well 



^ Gas Well 



4- Dry Hole 

 — - — ^900- — Structure Contour Lines, shewing Elevation 

 of Washington Coal -Bed above Tide 

 I H M H 1 2 3 4 



I I I I I M^^^— III • ^^^— ■ I I 



Scale of Miles 



Figure 3. — Geological Stnictiue of a Portion of the Volcano Anticline in Wood, Ritchie, 

 Wirt, and Pleasants Counties, West Virginia 



Showing type of fields of Subclass II (a), bounded on both sides by unproductive sub- 

 aclinal structure of Class I. Contour interval, 100 feet. (After I. C. White, G. P. 

 Grimsley, and Koy V. Hennen : County reports and maps of Pleasants, Wood, and Ritchie 

 counties, West Virginia Geological Survey, 1910.) 



