THE LOWER COAL MEASURES. 187 
centers of the county, Salineville and Palestine, depend upon this seam 
as the basis of their operations, though other seams are also worked. 
The above named seam completes the Lower Coal Measures, but 
this division might well have been enlarged to take in the next seam 
above, viz., the Brush Creek coal of Pennsylvania, or the Salineville 
Strip Vein, a seam which, though never attuining great thickness, is so 
excellent in quality and so steady in character that it has been worked 
in a small way in many counties of Ohio, but in no other section of the 
State does it attain the importance that it possesses in’ Columbiana and 
Jefferson counties. 
The frame-work of the series has now been given, and a few state- 
ments will be added as to the special fields. We can advance with 
most profit along the line of the Niles and New Lisbon Railroad, which 
we have already followed through Mahoning county. 
The sections at Leetonia and New Lisbon have already been given 
(see Figs. XI and XII), and they fairly represent the geology of the 
ten northern townships of the county. In the northwestern corner of 
the county, however, the deposits of the glacial drift cover the surface, 
so as to obscure the bedded rocks to a considerable degree. The sec- 
tion at Linton in the Yellow Creek Valley is shown in Fig. XIII, and 
this applies to all the lower portion of the county, except that 300 to 
500 feet of the Barren Measures come in above the summit of the 
Lower Coal Measures in that district. 
THe LEETONIA FIELD. 
The Leetonia coal field is an important one. It covers, not the 
heaviest, but, all things considered, the most valuable deposit of the 
Lower Kittanning coal in the State. The boundaries of the field, so 
far as it has been fully tested, are not wide. On the northward, as we 
have already seen, it does not extend beyond Green Station, being cut 
out beyond that, apparently, by the descent of the Lower Freeport 
sandstone. To the west it is found in fair volume and quality, as far at 
least as Salem, within the limits of which a shaft has been sunk to the 
coal and below. It thins out rapidly to the southward, and is scarcely 
found of workable volume again until it is followed beyond New Lisbon. 
To the eastward it has not been fully proved, but there are several facts 
that point toward a valuable extension of the field in that direction, 
