330 PALAEOZOIC TIME — CARBONIFEROUS AGE. 



the different coal basins, because the beds of rock as well as of coal — even those 

 that are the thickest — vary much at comparatively short distances over the 

 country. Moreover, as the basins are wholly disconnected, there is no chance 

 to trace even a single stratum from one to another. It is often assumed that 

 the Appalachian and Illinois beds were once united, and were afterwards 

 divided by the uplift of the Silurian about Cincinnati and extensive denudation 

 accompanying it. But it has been shown (p. 317) that this uplift probably 

 antedates long the Carboniferous Age; and, if this were so, the connection in 

 those latitudes is impossible. It is evident, therefore, that only the most general 

 conclusions on the subject of equivalency can be accepted as established facts. 

 The principal investigations on this subject are those of Lesquereux, who has 

 brought to it a thorough knowledge of the coal plants. 



The Coal measures of Pennsylvania and the States west include twelve to 

 eighteen distinct workable coal beds, besides thinner seams, the number vary- 

 ing in different regions from certain beds being comparatively local. In this 

 series there are two beds that have special prominence on account of their 

 thickness and the wide range they are believed to have. 



There are, first, the Mammoth Anthracite vein of Pennsylvania, which is the 

 second or third from the bottom, not far from the Millstone grit. 



Second, the Great Pittsburg bed, the seventh or eighth above the Mammoth vein. 



The following are the equivalents of these beds, according to Lesquereux : — 



(1.) Mammoth bed (Second workable Pennsylvania bed). — The bed at Leo- 

 nards, above Kittaning, Pa. (3J feet thick), etc.; Mahoning Valley, Cuyahoga 

 Falls, Chippewa, etc., Ohio ; the Kanawha Salines ; the Breckenridge Cannel 

 Coal and other mines in Kentucky, the first (or second) Kentucky bed; the 

 lower coal on the Wabash, Ind. ; Morriss, etc., 111. 



(2.) Pittsburg bed (Eighth Pennsylvania bed). — Bed at Wheeling; at Athens, 

 Ohio; the Well Coal, at Mulford's, in western Kentucky, the eleventh Ken- 

 tucky bed. 



The Gate and Salem beds correspond to the Upper Frecport (or fifth bed, west- 

 ern Pennsylvania) ; Pomeroy coal, Ohio, situated below the Mahoning sandstone; 

 the Curlew coal, of Curlew Hill, Kentucky, or the fourth Kentucky bed. 



In Kentucky, fifteen or twenty distinct coal beds exist. The eleventh is sup- 

 posed to correspond to the Pittsburg bed, and the others are above it. Above 

 the twelfth, there is the massive sandstone, 40 to 50 feet thick, called the Anvil 

 Rock, from the form of two masses of it in southwestern Kentucky. Six or 

 seven coal beds occur above the Anvil Rock, in about 500 feet of rock; but they 

 are very thin ; the whole amount of coal in this thickness is about 5 feet. 

 (D.D.Owen.) The thickness of rock in the Coal measures below the top of 

 the Anvil Rock is about 1000 feet, and of the included coal beds about 40 feet; 

 making, in all, for the western Coal measures of Kentucky, a thickness of 1500 

 feet, in which are 45 feet of coal. 



6. Sections of the Coal Ifeasures. — In western Pennsylvania, the western Coal 

 measures, to the top of the Upper Freeport Coal inclusive, consist, according to 

 Lesley,* of the following beds. The numbering of Lesley by the letters of the 



* Manual of Coal and its Topography, by J. P. Lesley, 12mo, 1856, Phila- 

 delphia. Lippincott & Co. 



