Columbia. - Area, 480 square miles; population in 1880,
32,409. Fishing creek and its branches- Huntington, Greene, Little
Fishing, Spruce, and Hemlock creeks - drain the northern nine townships
southward to the bend of the Susquehanna river between Bloomsburg
and Catawissa - a rolling country of Catskill, Chemung, and Hamilton
rocks (IX and VIII) spreading in front of the Allegheny mountain plateau,
the edge of which is here called the North mountain. A broad and gentle
anticlinal arch elevates a wedge of north hamilton rocks, the base
of which on the Mountour county line is six miles wide, and its eastern
point reaches to within four miles of the Luzerne county line. The
broad belt of Castskill-Chemung hills north of the wedge has a general
height of 800' to 900' A. T. The Hamilton wedge itself is less elevated,
and is bordered on the south also by a synclinal belt of Catskill-Chemung
hills, along the center line of which Pocono sandstone rocks (X) make
a long straight mountain (1500' A.T.) ending in a sharp point overlooking
Orangeville and affording a magnificent view of the country. Four
miles from its point the mountain top begins to split, the two crests
gradually become two separate mountains, the southern (N. dipping)
called Lee's mountain, the northern (S. dipping) Shickshinny mountain,
inclosing a narrow valley of red shale (XI) which, in Luzerne county,
continues to widen until it takes in the Northern Anthracite coal
field. The upper end of the little valley is choked with drift, and
the great Terminal moraine of the Ice age ascends Lee's mountain from
the south-east, descends Huntington mountain westward to Fishing creek,
which it follows northward through Benton and Sugar Loaf townships,
ascends to the top of the north and south dipping outcrops of Oriskany
sandstone VII, Lower Helderberg limestone VI, and Onondaga (Salina)
formation is finally exposed in the river banks at Bloomsburg, from
which place it has received its name. Fishing creek cuts square across
the rock arch, affording fine exposures with dips of 45o,
and here an abundance of Silurian, and Lower and Middle Devonian fossils
may be collected. (See Report G7.) The Stony Brook group
of strata in the upper part of the Chemung formation is specially
remarkable. Forms characteristic of the Tully limestone of New York
seem to be absent. Vast quantities of Halysites catenulata
of the Niagara formation occur in the Lower Helderberg limestone (VI)
at Mauser's quarry. A south dipping belt of VIII and IX lies south
of the river from Catawissa eastward, and those formations spread
over Roaring creek, Locust, and Franklin townships, brought to the
surface by the broad and rumpled Selinsgrove anticlinal, which, in
Schuylkill county, separates the Mahanoy coal field from that of the
Beaver Meadows. The rumples in this great arch are represented on
the map by the zig-zags of Catawissa Mountain, towards which the western
ends of the Eastern Middle Anthracite coal basins point. The elbow
of the mountain, overlooking Catawissa, is a double synclinal, and
runs on eastward as Nescopec mountain (S. dipping,) gapped at Mainville
by Catawissa creek, bringing out the drainage of the broad and winding
red shale valley which surrounds the Anthracite mountains. McCauley's
mountain, in Beaver township, a canoe-shaped fragment of the Conglomerate
XII, holding the lowest coal beds, stands alone in the Conyngham red
shale valley (XI,) on one of the two synclical lines which come through
the Catawissa mountain elbow. N. Conyngham township is a square piece
of Western Middle Anthracite coal field, included in Columbian county,
with its Hartville and Centralia collieries. This south end of the
county is crossed by Big and Little mountains (X and XII,) with a
narrow, straight, and deep red shale (XI) valley between them, through
which flows the south branch of Roaring creek which turns at the S.W.
county corner, breaks through Little Mountain (Pocono X,) and flows
north across the great rock arch to the Susquehanna below Catawissa;
the main creek drains the triangular area between the Catawissa mountain
spurs and the Little mountain. The iron works at Bloomsburg were established
on the numerous mines of Clinton fossil ore once worked extensively
in Scott township; the exhaustion of the softer outcrop ore, and the
leanness of the deeper unchanged portions of the beds, have compelled
the use of foreign stock brought from Lake Superior, northern New
York, northern New Jersey, and eastern Pennsylvania. A little lead
and zinc ore has been found in the limestone of VI, near the west
line of Center township, but the attempt to mine it was abandoned.
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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