62 J.J.STEVENSON — J.OWER CAEBONIFEROUS, APPALACHIAN BASIN 



last; the shales are absent and the limestones cannot be differentiated. 

 Four miles west the record gives 69 feet of limestone, but says nothing 

 of the overlying rocks. In northern Ritchie, at about 15 miles north 

 from the last and about 10 miles west from the Doddridge line, the in- 

 terval varies within a few feet from 20 to 75 feet, the limestone being 20 

 and 67 feet. There can be no doubt respecting these records, as they 

 are given on the authoritj' of Mr J. F. Carll. It is sufficiently clear that 

 in this portion of Ritchie onl}^ the silicious limestone remains. At 

 Harrisville, in the center of the county, shale, 8 feet, and limestone, 91 

 feet, are reported, while at Cairo one finds in the 90 foot interval 16 feet 

 of " Pencil " resting on the limestone, which at 50 feet from the top shows 

 a 12-foot sandstone; but the shale is absent from a well near b^^ Four 

 miles northeast from Cairo no shale is present and a 10-foot sandstone is 

 at 5 feet from the top of the limestone ; but 8 miles south from Cairo the 

 interval is 67 feet, filled with limestone. Doctor White states that the 

 upper shales are wanting throughout Ritchie, Tyler, Pleasants, Wirt, 

 Wood, and counties along the Ohio. In western Ritchie the interval 

 is from 16 to 44 feet and is filled with limestone. In the Hendershot 

 field, within central Wood county, the thickness of Mauch Chunk varies 

 from to 90 feet, the last being in the southerly part and 5 miles from 

 the other. Near the last the record gives the interval as 48 feet, with 

 limestones 15 and 18 feet, separated by 15 feet of shale ; but at Parkers- 

 burg, on the Ohio, at 5 miles southwest, the limestone has disappeared, 

 and between the Logan and the Pottsville one finds 65 feet of less massive 

 rocks, which may belong to either one or the other. The limestone is 

 absent from central and southern Washington count}^ of Ohio, adjoining 

 Pleasants and Wood of West Virginia.* 



The western limit of the silicious limestone is along the Ohio river 

 from north Washington county of Ohio to a little below Waverl}" in 

 Wood county. It passes east from Parkersburg. 



The next tier of counties consists of Lewis and Braxton at the east, 

 then Gilmer, Calhoun, Wirt and Roane adjoining Calhoun, Jackson, 

 and Mason along the Ohio river. 



Lewis adjoins Harrison at the south. Here one finds a record of 

 great value for the proper interpretation of the Harrison Count}' records, 

 for the boring was made at the extreme eastern border of the county 

 and barely 25 miles from the exposures in Rich mountain of Randolph 

 count3^ The succession is 



* The reference? for this tier of counties are Geol. of West Virginia, vol.i, pp. 250, 253, 285, 2S7, 

 294, 296, 297, 300, 301, 30:5, 306, 309, 314, 315, 318, 320, 322, 325, 329, 330, 



