Somerset. -Area, 1100 square miles; population in 1880, 33,110. This
county is sub-divided into three regions. The first and smallest consists
of Southampton township in the south-eastern corner of the county; a
semi-bituminous coal basin (the northern end of the Cumberland basin
in Maryland) 10 miles long and 2 ½ wide, of the lower coal beds surrounded
by a mountain of Conglomerate XII, Red Shale XI and Pocono Sandstone
X (Little Savage Mountain) cut through at the north end of the basin
by Brush Creek, which shows the general synclinal structure of the trough
very finely. The second region lies between the Little Savage Mountain
and the Great Savage or Allegheny Mountain, the crest of which is Conglomerate
No. XII faced with a terrace of Pocono. The space between the two mountains
is occupied by a belt of wild and broken country, 6 miles wide, of Catskill
rocks No. IX, elevated by a gentle anticlinal sinking southward, and
rising northward so as to bring up Chemung strata along its central
line, as explained in the description of Bedford County. The third region
of Somerset County embraces all the townships lying between the Allegheny
mountain and the Fayette and Westmoreland line; a region of bituminous
coal measures, divided into two great basins by the anticlinal of Negro
Mountain, through which Castleman’s river makes a fine gorge of five
miles between Garrett and Mineral Point, showing the arch of the conglomerate,
the red shale underneath it, and the first coal bed over it. The Lower
Productive coal measures occupy more than one half of the surface of
the region, and coal beds from 3` to 5` thick are mined for local use
at a multitude of points. The middle belt of each of the two great basins
is occupied by hills of the Barren Measures 600` thick, where they are
all preserved, on Castleman’s river on the first basin. In these Barren
Measures are several coal beds too small to work, except where they
become locally of exceptional thickness, especially around Berlin in
Brothers’ Valley township where one of the beds was for many years mistaken
for the Pittsburgh bed.
South of Castleman’s River, and rising from its west bank at Salisbury,
the center of the first basin is occupied by a long ridge in which
has been preserved a little coal field of the Upper Productive coal
measures, 5 miles long by 1 ½ miles wide, much broken into by side
ravines, but offering 3600 acres of the Pittsburgh coal bed, averaging
8` thick, and of excellent quality: Carbon (in four analyses) 68.7
to 70.2; vol. Matter 19.6 to 22.3; ash 6 to 8.3; water 1 to 1.7; sulphur
0.7 to 1.2 per cent. The section from the hill top down may be generalized
thus: Sandstone 40`; Uniontown coal; limestone 10`; shale 45`;
Sewickley coal; limestone 10`; shale and sandstone 44`; Redstone
coal; limestone 10`; shaly sandstone 30`; Pittsburgh coal
10`; * slate &c. 54`; limestone 5`; Saylor coal and three
other lower equally small coals, with shale intervals, 144`; Elk
Lick coal 4`; limestone 8`; shale 70`; Berlin coal 3` to
6` (slaty and sulphurous); shale 10`; limestone 8`; shale 5`; Platt
coal, good, 7`; interval 60`; Coleman coal, 2` (locally
6`); limestone 3`; interval 40`; Philson coal 1`; limestone,
3`; interval 100`; Mahoning sandstone (upper and lower, parted by
15` of shale) say 77`; total, Barren measures beneath the Pittsburgh
coal, 600. The section of Barren Measures in the Second Basin, from
the hill tops at Ursina down to the water level of the Younghiogheny,
at the Turkey Foot where Castleman’s river and Laurel Hill Creek join
it, shows 504` of shale and sandstone; holding one coal 6`, another
5`, and four others under 2` thick; two thin limestones near the bottom
and the double Elk Lick limestone (5` and 10` with a shale and coal
streak-parting of 3 ½`) within 7` of the hill top, which should be
200` higher to take in the Pittsburgh coal. The erosion of this basin
is illustrated finely by the isolated hill called "the Fort," 500 high, with its slightly scolloped flat top, and its
four sides beautifully terraced like a Mexican teocallis, or the "pyramid
of steps" in Egypt, each branch representing a horizontal coal bed
of the Lower Productive series, thus: Rose coal 1`; interval
(Mahoning) 100`; Coal E (Freeport) 2`; shale 1`; limestone
3`; interval 115`; Coal D; interval 40`; (coal ?) bench;
interval 70`; (coal ?) fire-clay, bench; interval 55`; coal,
thin; interval 15`; Coal A? 4`; interval (massive sandstone
blocks) 100`; coal (Mt. Savage ?) 1` to river level; 517`. (This series,
so important in the county, is better shown by the Johnstown section
in Cambria, already described. See also Report H2.)
* With a reported rider of coal (4` thick) 4` above it. See Report
H3, p.89.
From: A geological hand atlas of the sixty-seven
counties of Pennsylvania :embodying the results of the field work
of the survey, from 1874 to 1884. By J. P. Lesley. (Report of
progress (Geological Survey of Pennsylvania), v. X ) Harrisburg, PA
: Board of commissioners for the second geological survey, 1885.
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