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History of York County Pennsylvania From the Earliest Time to the Present online

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is the quartzite. Yet we have the best rea-
sons for believing that each is of contempora-
ry origin with its analogue in York County;
and indeed, the diiferences, which would not
be considered at all important by any but a
critical geologist, are what we might expect
when we remember that these rocks are sedi-
ments laid down at the bottom of successive
seas, and that their characters depended
upon the kind of material which different
streams, draining different parts of the coun-

try during different epochs, brought down
to be strewn out at different localities.*

It will be explai-ned before long that the
physical break between the Eozoie schists and
the limestone series is rendered highly prob-
able by the observations in York County; but
that between the flat arch belt and the Hellam
Township quartzite must rest upon the direct
evidence obtained in other counties, unless
here also we may apply the indirect method,
mentioned above, and conclude that inasmuch
as the Hellam quartzite contains one impor-
tant fossil, and the Eozoic schists contain
none that have been yet discovered in York
County, this fact alune entitles them to be
considered different formations.

This fossil is the SvoHthus linearity, and
is supposed to be the burrow hole left by
some boring worm, which inhabited the Hel-
lam (or Potsdam) sea. It was first recognized
and named by Prof. S. S. Haldeman in the
rocks of Chikis, and has since become one of
the most characteristic marks of the lower
Palaeozoic series, and one of the few widely
distributed fossils of this formation.

The Hellam or Chikis quartzite is a hard
quartzose rock of which tlie general color is
white or gray, tinted by some other color,
usually pink, brown, or blue, depending up-
on the minerals with which it has been
associated. It is almost always crystalline,
and in disturbed regions like this, is most
frequently found in broken fragments rather
than in continuous beds, owing to its brittle-
ness, which prevented it from yielding grad-
I ually to the strain which has folded and
tilted the other rocks of the county. These
strains have twisted, broken and crumbled it;
but on accouQt of its great hardness and its
resistance to the chemical action of the
atmosphere, it is the least altered or decom-
posed of ail the rocks to be considered here,
and almost always indicates its presence by a
hill, whatever be the position of its strata, j

It is not necessary to specify the localities
within the county, where this quartzite oc-
curs, because they are indicated by yellow oq
the geological map; still less is it desirable to
discuss here all the possibilities of structure
which these scattered out-crops suggest. It
is important, however, before leaving the
floor of the Pateozoic column to say that
eleven years of experience in the field have
caused me to doubt the correctness of ascrib-

*Let any one observe the great differences between the chiir-
acters of the sand beach of our own Atlantic coast within short
distances. See on this subject Delesse's important contribu-
tion entitled "Geologie du Fond des Mers," and the writer's no-
tice of the same in Proc. Am. Philos. Soc.

tXhe reason of this is that the erosion which has torn ort
hundreds and perhaps thousands of feet of the other measures
has not been able to reduce it to the same extent, and it remains
consequently as a hill or chain of hills.


ing to this formation the iron ores which are
'found in the schists immediately above the

The Grubb ore bank (No. Ill of the map)
is the only one wliich lies wholly with-
in the area of the Hellam quartzite, as given
on the map, but a reference to the disposi-
tion of this bank (Vol. C, p. fi4, '2d G.
S. of P.) leads to the belief that the larger
part of the ore lies in a small remnant of
the bottom schists of the nest higher forma-
tion, which has escaped the erosion that cut
off the higher layers of that formation. Part
of it. however, answers to the description of
an iron ore which may really belong to the
quartzite, and which has been noticed in the
rocks forming the outer casing of the South


In part the Calciferous Sand Rock of the
New York Survey). This important member
of the Palfeozoic series in York County con-
sists of at least two and perhaps three dis-
tinct kinds of rock, and inasmuch as the kind
that occurs at the bottom (resembling strong-
ly that which occurs among the limestone
beds themselves, and also above them) has
already been mentioned several times by an-
ticipation, it will be advisable to consider
it first.


It was previously stated that Rogers, and
following him, almost all other writers on
geology up to the commencement of the sec-
ond geological survey of Pennsylvania, had
given the name of "talcose slates" to a group
of rocks which he connected in epoch with
the quartzite. The word talcose was applied
to them because, from their softness and
greasy feel, it was assumed that they were
largely composed of "talc," which is a sili-
cate of magnesia containing water. But
subsequent investigations of these rocks in
the chemical laboratory have shown that
they contain little or no magnesia, and that
they derive their peculiar characters from
large amounts of a group of micas contain-
ing potash or soda and water. Prof. James
D. Dana conceived the happy thought of
naming the group the "Hydro-micas" or
water (containing) micas, and naturally the

*0f course if the Potsdam have an upper member consist-
ing of schists, the above assignment is correct; but I know of no
instance in which the opposite supposition is not equally sup-
ported by the facts. It is also to be noted that the limestone
and iron-ore bearing schists are more frequently found together
without the quartzite, than the quartzite and schists without
the limestone.

tCottrell & Benson's, and Smyser's mines [Nos. 11 and 112J
are on the border line between the quartzite and limestone.

rocks which mainly composed them are
called Hydro-mica* schists.

These hydro-mica, or nacreous schists, are
not of uniform appearance. Sometimes, and
especially in the beds that underlie the lime-
stone, they are lirmly compacted together,
making hard rock masses and high hills, as
at many places along the Susquehanna from
Wrightsville to Cabin Branch Run, and
elsewhere in the county. Sometimes they
are so much disintegrated as to form dust,
which on close view is seen to be mainly
made up of little glinting particles. In the
former case the beds are very often strewn
with little yellow crystals of metallic lustre,
composed of the sulphide of iron and called
pyrite by mineralogists, or mundic by the
miners. Again, in place of these little
crystals of iron (and occasionally copper)
sulphide are beautiful casts or moulds, of the
shape of cubes, more or less tilled with a
dark brown iron rust obtained from the de-
composition of the original crystals. These
little crystals have been of no small impor-
tance to the prosperity of York County, for
there is good reason for believing that by
far the largest part of its iron ores have been
derived fc-om their oxidation, transportation
by water and final deposition in the clays
formed from the grinding up of the rocks
which originally contained them.f

These argillites, or limestone-schists, as I
have sometimes called them, in all probabil-
ity hold all the important iron orej mines
of the county, outside of the formation of red
sandstone and shales. It is true that some-
times the iron ore banks appear to be far from
the area colored as limestone, and sometimes
directly within the boundaries of that area,
but in neither case is it under conditions that
forbid the belief that they are in the verita-
ble hydro-mica schists, even if the latter may
have been reduced by the weather to soft
unctuous and variegated clays. It is not too
much, therefore, to call this portion of the
York County rooks the real iron- bearing (or
ferriferous) region. The edges of the rock
appear in the right bank of the Susquehanna
River, where that river has cut through them,
and one would hasten to the part just above
WrightBville to ascertain whether these schists
were uncomformable upon the quartzite, but
the following records of the dip or inclination
of the two rock series, taken from Section 1
of my report on the county§, will show that

*This word is used for rocks which have crystalliue, as op-
posed to simple bedded structure. In the othercase t hey are
called slates.

tSee Vol. C, 137, 2d G. S. of Pa., by the author.

JSee notes, at the end.

gVol. C, p. 73.

both formations are so flexed or twisted, that
no certainty can be obtained there. First,
there are two dips in the quartzite of south
50^ and almost at the contact with the schists
south 20°, east 45°. Next, there are three
dips in the schists which are respectively
south 45°, south 10°, east 50°, south 10°
and east 10°. Still there is every probabil-
ity that in fact the dips of the two differ,
both in direction and amount, while there are
no such indications for the dips of the schists
and of the limestone proper at this place.


One of the best opportunities of measuring
the thickness of this limestone is afforded by
the section referred to along the Susque-
hanna from a little run half a mile above the
Columbia bridge to Kreutz Creek.* This is
evidently a trough with the axis clpse to the
bridge, and measures 2,800 feet of limestone
and included schists. If the schists between
the qaartzite and the limestone be included,
it would add some 1,000 feet to this, making
the limestone and the schists below it to the
quartzite 4,400 feet thick. The same beds
measured by me in Lancaster County only
amounted to 3,400 feet. These beds, there-
fore, may thicken 1,000 feet in the twelve
miles which intervene between this section and
the city of Lancaster, and of this thickening
400 feet belong to the schists below the lime-
stone and 600 feet for the limestone itself and
its included schists.f The limestone, of which
.numerous analyses will be found in Reoorts
C, CC, CCC, M and MM, is doloraitic, that is
to say, it is a carbonate of lime containing
varying amounts of carbonate of magnesia.
There is also some ground for believing that
two kinds of limestone are represented, each
having its own peculiarities of physical
structure. It was noticed in many cases that
two kinds of limestone were often exposed in
the same quarry, and that they usually
showed slight variations of dip. One, which
was apparently the elder, was of a buff or
grayish color and less marked stratification;
the other, blue, with white streaks and spots
of lighter colored limestooe (often calcite).
One case was recorded where, in a contact be-
tween the two, pebbles of the buff were found
in the blue. There seems no doubt that the
great mass of limestone now under consider-
ation was formed subsequently to the quart-
zite, and at about the epoch of the calciferous
sand rock of New York and before the Tren-

*In the .section above referred to it is probable tbat a furthei
study would enable me to abandon the hypothesis of non-con-
formability at (?, i, k and o, which I considered necessary tc
assume eleven years ago.

ton, or in other words in the Canadian epoch
of Dana. But no fossils were found in the
county to settle the question. The connec-
tion between the limestone near New Market
and that of York, which doubtless exists, is
covered up by the beds of the Mesozoic.
That which once connected that of Wrights -
ville and that near Prospect, has been washed
away in the general planing down of the
surface by erosion.


None of the numerous members of Mesozoic
rocks are known to be represented but the
groups of sandstones and shales known as
the "New Red Sandstone," and sometimes
the " Triassic Sandstone."

There are many puzzling questions which
arise from the study of these rocks, not the
least of which is their thickness. If one as-
sumes them to lie naturall)^ without distor-
tion, layer upon layer in York and Adams
Counties, their perpendicular thickness in
this region will be not less than sixteen thous-
and four hundred feet.* The lower bed of
this formation, which forms its eastern boun-
dary, is very generally a conglomerate of the
blue limestone pebbles imbedded in Mesozoic
rocks. This can be observed about two miles
west of York at Beeler's Cross Roads (Vol. C,
p. 92, Sec. 2a. )

The upper bed seems to be also a con-
glomerate, which forms its western bound-
ary on the slope of the South Mountain.
Rogers was in doubt whether the so-called
" Potomac marble " was represented by the
upper or lower of these (see Report CC, p.
265. ) Borings with the diamond drill by
Mr. Heinrich, recorded in the paper above
mentioned, show that no such thickness exists
in point of fact, as one might conclude from
the appearance of the beds; and the proba-
bility is that the actual thickness there is not
above fifteen hundred feet. No such borings
have been made in York County, but this
thickness is not likely to be greatly ex-
ceeded. But these measures in York Coun-
ty are chiefly interesting on account first,
of their fossils; second, of their iron ores;
and third, of their coal. From the former,
Prof. E. D. Cope was able to pronounce the

stone." Trans. American Institute of Mining Engineers, The
Mesozoic Formation in Virginia by 0. J. Heinrich ; The Trans.
A. 1. M. E., February, 1878; Notes on the "Mesozoic of Vir-
ginia " by Prof. William M. Fontaine. Am. Journal of Sc. and
A,, .Tannary. IS70; and "Some yesozoic Ores," Proceedings
American Philosophical Society, April 20, 1877, by the writer.
In the article cited second, and in a review of the others in the
American Naturalist, for May, 1S79, I have shown that by calcu-
lating the thickness of Prof. H. D. Rogers' Y'ardleyville section
of this formation (First Geological Survey of Penqsylvania), by
the ordinary method, the thickness of beds would appear to be
51, 500 feet, or nine and three quarters miles.


beds containing them undoubtedly of Triassic
age. The coal, which is found about three-
quartei's of a mile north of Liverpool on I.
Spahn's farm, and elsewhere, represents the
extensive deposits known as the Richmond
Coal Fields, which have been wrought in Vir-
ginia for a century to advantage, and are so
still. Although its analysis indicates it to be
a good bituminous coal (see CCC, p. 259)*,
yet it has never been found in Pennsylvania
in paying quantities.

Copper and other valuable metals have
been similarly observed in this formation
though in disappointing quantity in this
county, though they have supplied furnaces in
other parts of this State and in other States.
The richest deposits of these metals is usually
found near the borders of the formation.

no reason to believe that it appeared very
long afterward in a geological sense. The
most interesting features of the York County
Trap are. its appearance sometimes as a dyke
cutting through narrow clefts of the rocks,
and sometimes as mesas, or "tables," covering
large areas after having been poured out
from a comparatively small vent. One of
these may be seen in Warrington, and one in
MoQaghan Township. The chief coustitu-
tents of this rock are Pyroxene (or Augite)
and Labradorite (a lime feldspar). But mag-
netic oxide of iron is almost always present,
and Apatite is very generally so. The Tra]!
in Warrington is directly connected with the
mass in, and to the east of Gettysburg, and
is identical in composition with the so-called
"Gettysburg Granite."*


What has just been said of the copper and
other metals, may here be said of the iron
ores. Although an immense amount of iron
must have been consumed in providing these
beds with their characteristic red color, and
in fact large quantities of thin oxide scales
are to be observed almost everywhere between
the strata, the only localities, where iron
ores appear to have Ijeen found in any abund-
ance or permanence, are: first, those near
the margins of the new red sandstone, when
it overlies another formation containing iron
ore; and second, in the neighborhood of the
trap dykes, which contain over 11 per cent
of oxide of iron.j In the former case, it
is extremely probable that the deposits of the
older beds (as on the flank of South Mountain),
have been torn up by the agitated waters,
which laid down the Triassic rocks, and re
distributed as part of the latter. In the other
case it is very probable that after the decay
of the exposed jjortions of the Trap, part of
their iron oxide contents was concentrated by
natural water-flow, and carried into the cava-
ties and seams of the porous Mesozoic rocks.
The Traps, probably, not only supplied the
original material for these ore beds, but in
addition protected them from being washed
away, and new outbursts of molten rock very
likely gave them their altered appearance and
magnetic character.


Though the trap cannot be said to be
of the same age as the Triassic (since it
cuts through the highest beds and there
fore appeared clearly after the latest sedi-
mentary bed of the Mesozoic), still there is

*See Note 5, at the end.
fSee Note 6, at the end.


Of these, accepting the definition given
above, the only i-epresentatives are the marl
bed north of Dillsburg, and the gravels,
fluviatile deposits, and Indian sculptures on
the banks and islands of the great river.
Full descriptions and jAototypes of these lat-
ter will be found in Vol. CCC.



Note 1. — An analysis of a mica scliist, wiih iniliclrled
crysials, from half a mile norlhweal of Cully's Staiiou,
Clumbia & Port Deposit Kailroad, is added here lor a
comparison witli that of the Peach Boliom SUte, which
follows. (No. 1705 in Survey's catalogue of specimens,
CCC, p. 2?1.)

Per cent.

Silica (Si Oj) o9.01

Titanic Oxide (Ti OjJ 1.54

Phosphoric Oxide (Pj O5) (trace)

Aluiuina (AI2 O3) 17.02

Iron Sesqui-oxide (Fe^ O3) 7.76

Ferrous Oxide (Fe 0) 2.64

Manganous Oxide (Mn 0) '. 0.9b

Lime (Ca O) 2.08

Magnesia (Mg O) 0.07

Potash (Kj 0) 2.e3

Soda (Na^ 0) 2.44

Ignition 4.42

Sum 100.37

The rocks of which the above is an analysis corre-
spond with those between Centerville and Castle Fin
in York County, not far to the northwestward of the
Peach Bottom District,

Peach BoUom Slates.
Notes.— Ur. Andrew S. McCreath gives the follow-
ing report of a specimen of the Peach Bottom Slate
taken from J. Humphrey & Co.'s quarry, half a mile
east of Delta, York County. (P. 270, CCC.)

Per cent.

Silicic Oxide (Si Oj) 55.hi»U

Titanic Oxide (Ti 0,) 1.270

Sulphuric Oxide (S O3) 022

Alumina (AI2 O3) 21.849

»^See Note 6, at the end.

Ferrous Oxide (FeO) 9.033

Manganous Oxide (Mn 0) 0.586

Cobaltoua Oxide (Co 0) (trace)

Lime (Ca 0) 0.156

Magnesia (Mg 0) 1.495

Soda (Naj 0) 0.460

Potash (Kj 0) 3.640

*Carboii (C) 1.794

Water (H, 0) 3.385

Iron bisulphide (Fe S^) 0.051

Sum 99.800

Note 3. — The following analyses of two dififei-ent kinds
of ore from York County are given. The first is from
the "lower Auroral" or limestone schists. It is from
Earley & Killinger's Mine 2J miles east by north of
Littlestowu. It was analyzed by Mr. McCreath. (See
0, p. 44.)

Per cent.

Insoluble Residue 12.320

Iron Sesqui-oxide (Fe^ U3) 67.000

Alumina (Al^ 0,) 0.950

Manganese Sesqui Oxide (Mn, O3) 2.341

Phosphoric Oxide (P^ O5). ....". 2.804

Sulphuric Oxide (S O3) 0.277

Lime (Ca 0) 1.680

Magnesia (Mg 0) 0.591

Water (Hj, 0) 11.890

Sum 99.853

In the above there were :

Per cent.

Metallic Iron 46.900

Manganese 0.815

Sulphur 0.110

Phosphorus 1.224

The following is the result of an analysis of the
Mumper Mine in the Mesozoic Sandstone one mile
northeast of Dillsburg. (C, p. 71).

Per cent.

Ferrous Oxide (FeO) 18.643

Iron Sesqi-oxide (Fej O3) 42.100

Pyrite (Fe Sj) 4.093

Copper Sulphide (Cu S) 0.098

Cobalt Sulphide (Co S) 0.766

Alumina (Al^ O3) 2.417

Manganese Sesqui Oxide (MUj O3) 0.186

Lime(CaO) 6.132

Magnesia (Mg 0) 6.738

Potash and Soda 0.360

Phosphoric Oxide (P^ O5) 0.052

Sulphuric Acid (S 0,) 0.119

Carbonic Acid (C 0^) 1.760

Water (H^ 0) 1.080

Silica (Si Ojj) 15.120

Per cent.

Metallic Iron 45.880

Manganese 0.129

Magnetic Oxides of Iron 59.040

Ferric Oxide 1.703

Sulphur 2 680

Phosphorus 0.023

Note 4. — In MM, p. 344, Prof. Lesley gives some
analyses which derive their peculiar interest from the
fact that they are very numerous, and all from a com-
paratively small thickness in the Walton Limestone
Quarry opposite Harrisburg. His paper to the Am.
Phil. Soc. Proceedings was presented December 20,
1877, but the article just referred to is dated .lune 23,


♦Average of three determinations.

From analyses of 115 layers of the limestone exposed
in this quarry, it appears ihat

The Carbonate of Lime constituted 80.662

The Carbonate of Magnesia constituted 14.215

The Insoluble Residue constituted 4.715

These proportions will give a better idea of the av-
erage constitution of the good, merchan'able, York and
Cumberland limestone, than any number of scattered
analyses. Prof. Lesley's attempt to ascertain a connec-
tion between a given horizon and a constant proportion
of ihe carbonates of lime and magnesia to each other,
seems to have been suggested by some analyses which
I made previously niih the same end in view (See CC,
p. 307.) in 1875.

The analyses I made are as follows:

No. 1. From the west branch of Kreutz Creek near

No. 2. Upper bench of Pine Grove quarry.

Xo. 3. Lower bench of Pine Grove quarry.

No. 4. White limestone 100 yards east of Beeler's
Cross roads, 2 miles west by north of York.

No. 5 was from Detwieler'a quarry, northwest of

No. 6 was from Detwieler's quarry, south of

No.l No. 2 No. 3 No. 4 No. 5 No. 6 Av.
Specific gravity 2.832 2.735 2.731 2.750 2.737 2.770 2.759
lusohible sili-
ceous residue 4.100 12.270 12.000 3.570 0.490 41.710 *6.546
Alumina and

Ferric Oxide 1.170 1.540 0.450 0.210 1.440 6..350 0.962
Carbonate of

Lime 49.920 75.320 81.617 91.580 91.400 43.728 72.260

Carbonate of

Magnesia 42.9S0 10.750 6.400 4.110 7.290 0.450 12.996

Sulphur 0.220 0.120 0.422 0.113 0.003 1.480 0.175

Sum 98.690 100.00 100.489 99.583 100.623 99.718 99.850

Note 5. — Mr. A. S. McCreath's analysis of the coal
referred to is as follows:

Per cent.

Water 4.310

Volatile Organic Matter 18.482

Fixed Carbon (by loss.) 74.358

Sulphur 0.528

Ash 2.322

Sum 100.000

Rating this coal according to the system proposed by
me in a paper in the Trans. Am. Inst, of Min. Eng., and
subsequently published as part of report MM (Second
G. S. of Pa.):

The p. c. carbon: the p. c. Volatile Hydro-Carbons: :
80.1:19.9, and the "Fuel Ratio" would be 4, or within
the range proposed for the bituminous coals (5 to 0.)
Note 6. — The following is an analysis by Dr. Genth
of the trap (Dolerite) dyke which crosses Beeler's farm
two miles southwest of York:

Per cent.

Silicic Oxide 62..53

Phosphoric Oxide 0.15

Titanic O.xide 0.32

Alumina 14.35

Ferric Oxide 5.93

Ferrous Oxide 6.45

Manganous Oxide (trace)

Magnesia 7.99

Lime 10.27

Lithia (faintest trace)

Soda 1.87

Potash 0.92

Copper (trace)

Sulphur r 0.08

Ignition 1.23

Sum , 101.04

anted in the average.



By a mineralogical analysis of these results (C, p.
123*) it appears that there are two molecules of labra-
dorite and one of pyroxene, which together essentially
make up the rock.


THERE have been a number of great floods
along the Susquehanna river. Codorus
and Conewago Creeks and their tributaries.
The first great one on record occurred in 1744,
second in 1758, the thh-d in 1772, the fourth
in 17S4, the fifth in 1/S6. The last named
was known, along the river, as the great "pump-
kin flood," by which, on low places along that
stream, immense quantities of pumpkins were
lodged that had floated down with its ciu'rent.
The sixth flood occurred in ISOO, the seventh
in 1S14, the eight in 1817, the ninth in 1822,
the tenth in 1846 and the eleventh in 1884.
There were a number of destructive ice floods
along the river; among them were those of

Online LibraryJohn GibsonHistory of York County Pennsylvania From the Earliest Time to the Present → online text (page 97 of 218)