JEFFERSON OOUNTY. 725 
- county or in the adjacent townships of Columbiana, have shown that the 
Waverly Group is reached within two hundred feet of the “Creek Vein,” 
and hence that the base of the Coal Measures is there passed, and that 
no more coal can be hoped for at a greater depth. Along the northern 
margin of the coal field the lowest coal seam in the series is in many 
localities of workable thickness and of superior quality. It is there 
known as the Briar Hill, or Massillon coal, and from its development in 
the Mahoning and Upper Tuscarawas Valleys, has proved to be one of 
the most important and valuable coals of the series. Much effort has 
been made to find it in the interior of the coal basin, but up to the pres- 
ent time it has been nowhere struck of workable thickness on the Ohio 
River. 
Associated with the coals of the Lower Group are numerous beds of 
limestone, fire-clay, and iron ore, which have more or less economic value, 
and some of them will be referred to more specifically further on. The 
limestones have been generally taken as guides in the identification of 
the coal seams, but it unfortunately happens that they are somewhat 
local, and that in one place or another beds of limestone are found in the 
intervals that separate each two of the coal seams, hence they have 
proved as great a hindrance as a help in the study of the geology of the 
county. At Salineville a limestone is seen between Coals 7 and 6, 
another between 6 and 5, and still another beneath No. 5. At Irondale 
no limestone has been discovered under No. 7, while that under No. 6 is 
two feet in thickness; that under No. 5 (the “Roger Vein”’) three to five 
feet thick. No limestone has been detected at Irondale between Coals 3 
and 4 (the “Strip” and “Creek”). At Collinwood limestones occur 
under Coals 7, 6, and 5, and none, so far as known, between 4 and 3. At 
Linton a limestone five feet thick is seen under Coal No. 7, on the west 
side of Block House Run; on the east side it has not been detected. No 
limestone has been found beneath the “Big Vein” at Linton, and Coal 
No. 5 and its limestone are either wanting or concealed, while a thin 
band of limestone occurs beneath the “Strip Vein”—Coal No. 4. Along 
the river a limestone is seen under Coal No. 5, at Elliotsville, Croxon’s 
Run, and Sloan’s Station, but no limestone has yet been discovered under 
the upper seams. In the vicinity of Brown’s Station the hills contain 
six limestones, viz: (1) that under the Pittsburgh coal; (2) the crinoidal 
limestone; (3) a thin bastard or earthy limestone about sixty feet above 
Coal No.7 (Fleming’s); (4) a limestone under Coal No. 7; (5) an impure 
limestone over Coal No. 6; (6) a limestone immediately beneath Coal . 
No. 6. At the mouth of Wills Creek, at Boreland’s Shaft, and at Rush 
Run, a limestone occurs beneath the fire-clay of Coal No. 6. 
