THE ALLEGHANY COAL-FIELD IN KENTUCKY.
We shall briefly present a few of the leading features of this portion of the great coal-field, since it is but little developed, and presents but few points of special interest, where the coal is intersected by navigable rivers, since it lies near the head of the streams. Its margin, of course, on the north lies along the Ohio ; but we think the Big Sandy and the Cum berland are the only navigable waters which intersect it. The Big Sandy runs its full length over or among coal-beds, but only the upper waters of the Cumberland, which are seldom navigable, reach this coal-field. None of the Kentucky railroads penetrate its almost unbroken area, except a short branch at Ironton on the Ohio. The coal-area occupies all or part of twenty counties in Eastern Kentucky, and embraces an extent of 10,000 square miles. The western margin of the field enters Kentucky near Portsmouth on the Ohio, and leaves it near Monticello, a short distance below and east of which it crosses into Tennessee, the general course being southwest.
The Big Sandy is navigable through Eastern Kentucky a distance of 100 miles when the streams are high, and the coal is found either below or above water-level the whole distance. Below and in the vicinity of Louisa, at the confluence of the Tug Fork of Big Sandy, most of the coal lies below the bed of the river, but farther up it commences to rise above the river, and the seams of coal which may lie one hundred feet deep at Louisa are five hundred feet above the river at the Russell Fork. The dip is therefore general and gradual from the east to the west until the Ohio is reached, and from thence it is reversed and from the west to the east. Some distance above Prestonburg considerable coal was mined before the war, the coal being floated down in barges during high water. The localities
of the mines in this section are about half-way up the sides of the moun tains, and, we should judge, below the Mahoning sandstone.
From a hasty and necessarily brief examination during the year 1864, when this region of country lay between the lines of the Rebel and Union armies, and when guerrillas had full sway, we concluded the large seam worked on the Louisa Fork of Big Sandy to be identical with the cannel coal over E, since the Mahoning sandstone seemed to lie above. The coal produced was excellent, and contained about 60 per cent. of bitumen.
The above corresponds very nearly with the Kanawha section, and is almost identical with a section taken on the Tug Fork of Big Sandy in the Kentucky Geological Survey. Coal E is there wanting; but the space evidently admits of its existence, and we must conclude the error to be with the survey and not in the measures. The evidence of regularity and uniformity in the coal-seanis of this field is too great to be doubted.
Our exploration of this portion is too limited to enable us to locate the iron ores and limestones which accompany the principal seams ; but the short investigation we were able to make left no doubt on our mind that they existed in "place" and in order on the same geological horizon with the measures of Virginia and Pennsylvania.
The amount of coal mined in Eastern Kentucky may have amounted to 300,000 tons per annum before the war. We may safely put it, however, as low as 250,000; though since and during the war but a very small por tion of that amount has been mined. Nothing has been done on Big Sandy, and but little if any mining has been done on the Cumberland in Eastern Kentucky during the war.