DUNKARD FORMATION 105 



terval, in Smith township of Washington, the beds are 110 feet apart. 

 Along tlie west side of the county this increases to 140, 150, and 160 at 

 the Greene county line; but thence the increase is more rapid, so that 

 in southeastern Eichhill township of- Greene it is 240, and at a little 

 southwest in Aleppo it is 308 feet; the same interval is found in Marshall 

 county of West Virginia, 7 or 8 miles farther southwest. One finds the 

 increase in a southeasterly direction, 110, 135, 140, and as one approaches 

 the Greene county line, in Amwell of Washington, 180 to 190 feet. 

 Where the beds are reached again, in Franklin of Greene, the measure- 

 ment is 270, and in Perry, near the West A^irginia line at the south, it is 

 about 300 feet. Westwardly, in Ohio county of West Virginia, the inter- 

 val is 140, and in the adjacent part of Washington county it increases 

 south of west in 15 miles to 244 feet at Moundsville, and in 23 miles 

 southward to 308 feet at Belton. What the conditions are beyond one 

 may not assert positively, but if one may decide from the relations of the 

 JoUytown coal bed, the interval decreases notably toward the southwest. 



The variations in character of the rocks in this interval is important. 

 The limestones are the chief features of the section in Washington 

 county, especially in the central portion of the county; in all directions 

 they become thin, so that in Marshall of West Virginia at the west all 

 have disappeared except the Upper Washington; in Fayette, all are thin; 

 southward, in West Virginia,, all disappear quickly except the Lower 

 Washington. Massive sandstone is rare in Washington and Greene, 

 though occasionally one finds in those counties as well as in Fayette a 

 massive rock underneath the Upper Washington. Other sandstones be- 

 come noteworthy farther south until in Washington county of Ohio and 

 the adjacent counties of West Virginia one finds the great sandstones 

 quarried for grindstones and termed by I. C. White the Marietta sand- 

 stones (1903). He has found these beds more or less prominent in the 

 southern part of the Dunkard area within West Virginia. 



The nest characteristic interval, that between the Upper Washington 

 and Nineveh limestones, is followed with great ease within Pennsylvania. 

 The Mneveh limestone, at the top, is 25 to 35 feet below the Nineveh 

 coal bed, which underlies the massive Nineveh sandstone. The massive 

 rock above has protected the underlying beds in the most important 

 localities, so that there is little danger of error in identification of the 

 Mneveh limestone. The lower limiting bed, the Upper Washington 

 limestone, is equally well defined, not only by its associated beds, but also 

 by its peculiar features. 



The Ten-mile limestone, VII of volume K, is a persistent bed about 

 14 feet above the Upper Washington in central Washington county; but 



