Indiana. - Area, 830 square miles; population in 1880,
40,527. With the exception of five spots in as many gaps, and four
other spots on the anticlinal axes, the whole surface of the county
is occupied by the coal measures. The south-east county corner is
in the bed of the Conemaugh river in the center of the Johnstown gap
through Laurel hill, where XII, XI, X, and perhaps a little Catskill
IX arch over each other. The north-east corner is on the crest of
the continuation of the Chestnut hill arch, in the midst of a wilderness
elevated 2000 feet above tide. The east line of the county therefor
crosses diagonally the Ligonier valley coal basin, which, however,
is divided into two sub-basins by a low anticlinal arch running through
Nolo P.O. and Kimball P.O., bringing up the conglomerate (XII) on
Yellow creek at Strongstown. Both sub-basins are so deep that they
are filled with the Barren Measures, but the Productive coal beds
crop out along the valleys which follow or cross the anticlinals,
and an irregular belt of them, 2 or 3 miles wide, follows the great
Chestnut ridge axis from Blairsville to the Jefferson-Clearfield county
corner. This belt widens to 5 miles on the Conemaugh, and in the district
of the south branch of Little Mahoning Creek, around Robertsville,
Smethport corners, and the heads of Bear run where coal-outcrops are
abundant. At the first great bend below Blairsville the "Indiana anticlinal"
arch crosses the Kishkimenitas river and runs in a wonderfully straight
line past Indiana (1 mile E. of the town) and Kintersburg (Gilpin
P.O.) to the Little Mahoning one mile above Richmond, and so on to
the Jefferson line at the N.E. corner of Canoe township. The basin
between this axis and that of the Chestnut ridge, drained by Two Lick
and Black Lick runs, is only deep enough to hold the Productive coals,
with some areas of Barren measures in its hill tops; but, going south,
the Barren measures take possession of the whole surface west of the
Two Lick, and then invade the whole basin from Homer (Philip’s mills)
southward. In the east end of Black Lick township the basin gets deep
enough to take the Pittsburgh coal bed into its hill tops, and in
Burrell township the hill north and east of Blairsville hold this
bed (under a cover of 150 feet of upper measures) running about 6
feet thick and not very good, and lying about 200 feet above the river.
At the second bend above Saltzburg the "Saltzburg anticlinal" arch
crosses the river and runs on straight to the south-west corner of
East Mahoning township where it flattens out and is lost; but here,
on a line 4 miles further west, the "Perryville anticlinal" arch starts
and runs on into Jefferson county at the N.E. corner of West Mahoning
township. The Saltzburg axis crosses McKee’s run near the mill, and
exposes the Freeport Upper coal bed (E,) but all the others are underground,
and the surface of the whole country is occupied by the Barren measures.
Bed E is also brought to the surface in the bed of the Little Mahoning
by the Perryville axis. The basin west of the Indiana axis, and between
it and the Saltzburg and Perryville axes, is nowhere deep enough to
allow the Pittsburgh bed to be preserved in any of its hill tops.
But west of the Saltzburg axis all the higher lands of Young and Conemaugh
townships between the streams which enter Black-Log creek from Armstrong
county contain the Pittsburgh bed, 10 feet thick, with its regular
upper bench and main clay parting as in the Monongahela river country.
(See a description of Ashbaugh’s, Alms’, Ewing’s, Evans’, George’s,
and Holston’s mines in H4, pp.274-278.) The highest geological
ground in the county is in Elde’s ridge, 4 miles N.E. of Coalport,
where 200 feet of measures, capped by the Great limestone, and containing
the Sewickley coal and limestone, the Redstone coal and the Pittsburgh
Upper sandstone overlie the Pittsburgh coal bed. On Harper’s run 217`
of Barren measures may be seen beneath the Pittsburgh coal bed, containing
thin fossiliferous limestone beds, olive and
red shales, and the Morgantown sandstone (50` thick) the massive upper
15` member of which makes the picturesque cliff scenery of this quarter
of the county. The Barren measures in Indiana county may be called
600` thick. Nowhere in the Ligonier basin has more than lower 400`
been preserved. Seven or eight coal beds exist in the Barren measures,
but no reliance can be placed on any of them, although one or another
may be found in a good condition (3 or 4 feet thick) in some restricted
locality, like Painter’s coal at Nineveh and the Philson coal at Armagh.
The beds seem to be pretty persistent throughout the region, but running
only one or two feet thick. The Green Crindoidal limestone and the
Black Fossiliferous limestone of the Barren measures are of not much
economic importance, but have great geological value as bases of measurement
down to the Productive coal beds. Limestone is very abundant in the
county and the beds very numerous. Besides the two above mentioned
there are three others in the Barren measures and six in the Productive
coal series, of which the Freeport Upper limestone is 10` thick in
several parts of the county; the Freeport lower 6` on Two Lick; the
Johnstown Cement bed (under coal D) varies from 2` to 16`, and is
15` in Black Lick gap; but the Ferriferous limestone, which
is the great key rock of all the more western and northern counties,
fades away to nothing at the Indiana anticlinal, and is nowhere to
be found to the eastward of that line. The coal beds of the county
will in future years be mined mostly by shafts. The uppermost one
of the series (Freeport Upper coal E) is 150` beneath the Conemaugh
river at New Florence and 600` at Blairsville; 400` underground beneath
the turnpike between Armagh and Lings, and so on elsewhere; where
it comes to the surface it is a fine bed from 3 ½` to 6` thick, at
Griffith’s and other mines on Yellow Creek 7`, at Agey’s and St. Clair’s
on Two Lick 7` 3", on Mckee’s run 7` 4". The Freeport Lower coal (D`)
is unreliable, varying from 1 ½ to 4 ½`. The Kittanning Upper coal
(D) gets up to 4 ½` on Little Yellow Creek, and 5 ½` in the German
settlement. The middle coal is 3` (C`;) the lower coal (C) small,
but is 4` at McFarland’s at Greenville. The Clarion coal (B) is a
noble bed ranging widely as 4` to 8` thick over a valuable fire-clay;
but the famous fire-clay bed of Bolivar is under the Brookville coal
A. There seems to be very little workable iron ore in the county.
No evidence of the existence of productive oil sands has been obtained;
most of the wells bored have been too short to reach the Venango oil
rocks, much less the Warren and Bradford horizons. Of the natural
gas springs, that of "Burning Spring" in Deep Hollow, two miles below
Blairsville, is best known, but it comes from the Mahoning sandstone,
which yields oil and gas on Dunkard Creek in Greene County.
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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