JEFFERSON oou:^TY. 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, eo 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 EUiotsville, 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. 



