52 The A))rcrican Geologist. January, 1 898 
Area. Before the drill of the petroleum-seeker had pene- 
trated every region of the great Appalachian basin, it was 
supposed that the Pittsburg coal spread in a continuous 
sheet under every portion of that area where its outcrop was 
buried from view. This conclusion was based upon the un- 
failing continuity of the bed southward for 200 miles from 
Pittsburg to the head waters of the Monongahela, and also 
westward into Ohio, and its reappearance on the river of that 
name at Pomeroy, as also on the Great Kanawha at Ray- 
mond City, Pocatallico, and Charleston. But the studies of 
professor Orton and others in Ohio and my own in West 
Virginia, aided by the petroleimi drilling there, have shown 
that the coal is absent, or but poorly developed over large 
areas where it had formerly been considered present. Hence 
to the list of counties of West Virginia named in Bulletin 
65, United States Geological Survey, page 64, where this 
coal is absent, or in poor development, must now be added 
Doddridge, Tyler, and probably half of Wetzel, since two 
tests with the diamond drill near the centre of the latter 
county found only two feet of coal at a depth of 425 feet 
below the valley of Fishing creek. This area, together with 
that previously known to be barren, or to have only a patchy 
development in West Virginia and Ohio, will aggregate be- 
tween 4,000 and 5,000 square miles, a rather startling figure 
when subtracted from the supposed area of a coal-bed so 
valuable as the Pittsburg in its developed regions. 
There has been much speculation as to the area which 
this coal may once have covered. The isolated patches of 
the bed in the Georges creek and North Potomac region; 
the few knobs of it in Preston, Barbour and Upshur counties 
of West Virginia, together with its presence in the solitary 
peak of Round Top in Bedford county, Pennsylvania,. 45 
miles from any other outcrop of the bed, and far east of the 
Allegheny mountains, have led many geologists to believe 
that the Appalachian Coal Measures may once have ex- 
tended northwestward to the Lake region, and eastward pos- 
sibly to the North mountains, or even to the Blue ridge, 
having been removed from all this wide expanse by the enor- 
mous erosion to which it has been subjected since Carbon- 
iferous time. Whether the limits thus assigned were ever 
