JEFFERSON COUNTY. 723 
THE LOWER BARREN MEASURES. 
The Lower Barren Measures of western Pennsylvania have a typical 
representation in Jefferson county. The series is about 450 feet in thick- 
ness, and consists here chiefly of olive and red shales, with intercalated 
bands of red and yellow sandstone, two or more strata of limestone and 
two or three small seams of coal. About the middle of the Barren Meas- 
ures occurs a limestone which is remarkably persistent in place and 
uniform in character. It varies somewhat in thickness, but is usually 
from three to five feet, is gray in color, and contains numerous and char- 
acteristic fossils; these are largely portions of crinoids, and hence we 
have called it the Crinoidal limestone. Perhaps the most abundant fossils 
contained in it are the spinous plates of Zeacrinus macrospondylus. It also 
contains many mollusks, such as Spirifer cameratus, 8. Kentuckensis, Retzia 
punctulifera, Productus longispinus, P. semireticulatus, P. Nebracensis, Hemipro- 
nites erassus, and Chonetes Smithit, and numerous fish teeth of the genera 
Cladodus, Petalodus, and Ctenoptychius. In the northern part of the county 
the crinoidal limestone caps the hills bordering Yellow Creek, and the 
red and green shales which underlie it are conspicuously shown on the 
hillsides above Salineville and Irondale. 
Passing southward from the valley of Yellow Creek, the first oppor- 
tunity of measuring the distance between the Pittsburgh coal and the 
first of the lower group—the ‘Groff Vein,” Coal No. 7—occurs near Knox- 
ville. Here the distance between the Pittsburgh Coal and the crinoidal 
limestone, as measured by barometer, is about 165 feet. In the section 
taken from Richmond to Brown’s Station, the interval between the Pitts- 
burgh seam and the crinoidal limestone: is 207 feet, and the distance 
from the Pittsburgh seam to Coal No. 7 at Fleming’s mine is 423 feet. 
In the section from the highlands down to the mouth of Wills’ Creek, . 
the distance from the Pittsburgh seam to the coal beneath the crinoidal 
limestone—the limestone itself not being seen—is 230 feet, and to Coal 
No. 7 is 488 feet, to Coal No. 6 552 feet. At Steubenville Coal No. 7 is 
apparently wanting, and the interval between the Pittsburgh ccal and 
Coal No. 6, the “Shaft coal,” is at the rolling-mill shaft 506 feet. At 
Boreland’s shaft it is 198 feet from the Pittsburgh coal to the crinoidal 
limestone, and 511 feet to the shaft coal.* At Mingo Station the dis- 
“I am told by Mr. John Lowe that measurements carefully made by the county 
surveyor show that at Averick’s shaft, which is 204 feet deep, the Pittsburgh coal lies 
365 feet above the shaft mouth, making the distance between the two coals 569 fect. 
The same authority reports the distance between the Pittsburgh and shaft coals at 
Spaulding, Woodward & Co’s shaft, to be 534 feet. The measurements given above and 
on our charts were from observations taken with the aneroid barometer, by several 
