786 GEOLOGY OF OHIO. 
coal field lies so near the great lake market, that it has become the basis 
of anextensive commerce, and the mainspring of the most important 
iron industry of the west. Hence the land which holds the coal has 
acquired great value, and workable deposits have been sought with 
avidity through many years. From the fact that the basins which holds 
the coal are so narrow and few, much of the exploration made has 
resulted in disappointment ; but such explorations have borne this fruit, 
that they have made the details of the local geology of Mahoning Val- 
ley better known than that of any other district in the State, and they 
have enabled us to trace the outlines of the productive coal areas and 
the barren intervals, with a degree of accuracy which would otherwise 
have been impossible. Since most of the coal basins are completely 
buried, and show no lines of outcrop, the search for coal has for the 
most part been conducted by boring. By this means the northern part 
of the county has been, not thoroughly, but generally explored. Though 
much yet remains to be learned in regard to the connections between 
the different coal basins, they seem to lie somewhat in belts which have © 
a general direction a little east of north and west of south. For example, 
the Mineral Ridge belt of mines extends from Warner & Co’s. slope in 
Weathersfield, to the southern part of Austintown, and includes the 
mines of the Cambria Coal Co., Todd & Wells Coal Co., Baldwin Bros. 
Harris, Maury & Co., and the Harroff Coal Co. A similar belt of mines 
extends from Vienna through Liberty township, Trumbull county, and in 
Youngstown includes the Brier Hill mines and those of the Powers Coal 
Co., the Mahoning Coal Co., the Foster Coal-Co., the Kyle Coal Co., ete. 
There is another line of mines along the west side of Youngstown town- 
ship, reaching into Coitsville. This includes the slopes and shafts of 
Andrews & Hitchcock, Arms, Powers & Co, the Holland Coal Co., and 
the Andrews and Powers mines south of the Mahoning. Between these 
belts there is much territory, which, up to the present time, has seemed 
barren, but it is possible that future explorations will prove the exist- 
ence of valuable coal basins in the districts that are now regarded as 
unproductive; and will also show that the linear arrangement of the 
amines which has been referred ‘to is merely accidental. 
Within the limits of the productive territory the coal basins have been 
shown by the explorations and workings to form comparatively narrow, 
irreguiar and often branching channels, such as would be produced by 
the growth of peat in the excavated valleys of streams, if such streams 
were dammed up, and their waters made to form marshes. How far the 
basins now known are connected remains to be shown by future explora- 
tion, but there is ttle doubt that most of them form parts of continuous 
