COAL-FIELDS OF OHIO. 
319 
tombed beneath thick strata of shale and sandstone, 
until the whole series had accumulated to a depth 
of more than a thousand feet ; while beneath the 
whole lay the bed of an ancient ocean, floored with 
fossil salt. Indications of coal are found at inter- 
vals across the great valley from the Alleghany to 
the Rocky Mountains. It is found near the surface 
in Kentucky, Ohio, Indiana, Illinois, and Missouri, 
and, without doubt, may be found beneath the ex- 
tensive tertiary deposites which form the substra- 
tum of the great prairies in the central and northern 
parts of the Western states. As low down as New- 
Madrid, on the Mississippi, coal was thrown up from 
beneath the bed of the river by the great earthquakes 
of I8I2 ; a sufficient proof of its continuation in the 
most depressed part of the great valley." " Where 
not removed by degradation or buried under other 
strata, there seem to have been eight distinct de- 
posites of coal throughout the main coal-region of 
Ohio, some of which were covered with marine de- 
posites ; in others the deposite was made in fresh 
water, as is demonstrated by the character of the 
fossil shells found in the rocks, both over and under 
the coal." 
Coal-field of the Muskingum. — The Muskingum 
River empties into the Ohio on the west, after trav- 
ersing Muskingum, Morgan, and Washington coun- 
ties, through a beautiful valley nearly 200 miles in 
length, by from 50 to 100 or more in breadth. All 
the northeast part of the valley, and the hilly sand- 
stone region south and east between the Muskin- 
gum and the Ohio, belong to the carboniferous group 
.and the coal measures ; and nearly all the streams 
that flow into the Ohio, in some part of their course, 
pass over deposites of bituminous coal ; while the 
streams which run north into Lake Erie pass over 
calcareous rocks, and lie without the margin of that 
great coal-basin, through the most depending part 
oi which the Ohio takes its course. 
