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HISTORY OF BUCKS COUNTY.
CHAPTER 1.
GENERAL TOPOGRAPHY AND GEOLOGY.
TOPOGRAPHICALLY, the state of Pennsylvania
may be generally divided into three great divisions: The southeastern section,
a region of broad, fertile valleys and scattered hills ; the middle belt, some
fifty miles wide and two hundred and thirty miles long, consisting of peculiarly
symmetrical mountain ranges and narrow valleys, and a high western plateau,
deeply seamed by various water-courses.
It is with the southeastern sect ion that
these pages are especially concerned. This region is separated from the middle belt by the
Kittatinny range, through Which the Delaware and Susquehanna rivers force their way,
and thence along fertile valleys and rugged peaks to find their outlet to the
sea. The South Mountain range and the Susquehanna river naturally suggested
the early bound between the whites and the Indians, but the limits finally
fixed-for Bucks county were the arbitrary dictations of convenience. As it
now exists, the county forms an irregular parallelogram, extending from the
great bend of the Delaware river along its course in a direct line of about
forty miles, with an average width of about fifteen miles, and containing about
six hundred square miles. Inclosed within the foothills of the South Mountain
range and the upper limit of the tidewater plain of the Atlantic, it
consists of a beautifully diversified, undulating region, sloping gradually from an
altitude of one hundred and forty feet (A. T.) at its upper limit to a few feet
above tide level at its lower extremity. A steeper grade is discovered in passing
westerly from the river, the altitude at Quakertown being marked at five
hundred feet (A. T.).
A more than usually diversified geological
structure confers upon this county a great variety of scenery. Above the level of its
general surface rise numerous hills and low ridges of swelling outline. A
prevailing softness of contour especially distinguishes its lower portion, which may
be attributed to the general absence of the harder igneous rocks and coarse
sandstones, and to
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the presence of the easily disintegrated and crumbled
varieties of gneiss, metamorphic schists, etc., that underlie the surface. The
northern portion, composed for the most part of a broad zone of friable red
shale and argillaceous sandstone, exhibits a smooth and rolling landscape,
except where dykes and ridges of trap-rock protrude through the softer mass.
The extreme northern end of the county is traversed by a
portion of the South Mountain chain, and presents a very uniform, general
aspect, though internally of great diversity of structure and variety of local
scenery. It is remarkable for its evenness of summit and parallelism of its
crests or ridges. It is formed of two well-marked parallel ridges, extending
from the Delaware, across the northern corner of the county in a,- southwest
direction, to the Schuylkill at Reading. These ranges are a prolongation of the
Highlands of New Jersey, and inclose some pleasant agricultural valleys. Their
average elevation above the bordering valleys scarcely exceeds four hundred
feet, but being abrupt and presenting a marked barrier to the view, they receive
the name of mountains, which are more properly applied to other parts of the
chain of which they are but the termination. The regular contour of the central
region is varied by a broken range of hills which extends nearly due west from a
point on the Delaware in Solsbury township, just below New Hope, to the central
part of Buckingham township where the Durham road skirts its base about a mile
below Centerville. At this point the range ends somewhat abruptly and is known
as Buckingham mountain, and is only crossed by a zigzag road near the middle of
its extent in this township. It is a rugged elevation of some 250 feet above the
bordering valleys, and is still generally clothed with its original timber. The
colored people have erected a church upon its summit near the road which crosses
it, and a few clearings have been made at different places on it; but its chief
economic value is found in the timber it supplies. Toward the Solsbury line the
elevation rapidly diminishes to a level with the general surface. Passing toward
the river a gradual rise develops the Solebury mountain, which extends with a
slight southerly curve and ends abruptly at the Delaware. Bowman's mountain is
an isolated rocky elevation on the boundary line between Solebury and Upper
Makefield, and Jericho mountain is a similar elevation near the central portion
of the latter township. In the northeast section of Haycock township is a
symmetrical mound-like elevation known from the peculiar character of its
contour as 11 The Haycock." It is a rough, rocky
structure forbidding in every aspect, and save for its timber and an extended
outlook to be had from its summit, is without natural attractions. No road as
yet renders its economic resources readily available, but a movement to remedy
this defect is now being made.
Bucks county lies almost wholly within the
valley of the Delaware, and discharges its waters directly into that stream
through its own water-courses. The river forms the boundary on the eastern side
and lower end, and from this
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side of the county receives the waters of the Durham,
Tohickon, Pideock, Knowles, Hough, and lesser streams. At the lower end, it
receives the Scott, 'Mill, Nesbaminy, and Poquessing creeks. 11
The Haycock," with a ridge extending southwesterly from it, divides
the drainage of the upper region of the county, and the Perkiomen, taking its
rise on the southwestern slope of this divide, flows a nearly direct course to
the Schuylkill. The principal local stream, however, is the Neshaminy, which
clearly indicates the general topograpby of the central and lower portions of
Bucks. Rising not far from the Delaware, in Plumstead township, it flows in a
westerly course until it passes beyond the influence of Buckillgham mountain,
when it turns, almost at right angles to its previous course, and proceeds in a
southerly direction to the river .at the lower end of the count . It is throuah
this stream and its affluents that the larger portion of the natural drainage of
the county is effected. The Poquessing, which forms the lower boundary and
determines that of the upper part of the southwestern side of the county, rises
in Southampton and receives numerous little runs from Bensalem. The Pennypack
rises in Warminster but, flowing nearly due south, it leaves the county before
it gains a size of even local importance. Some of these streams are themselves
true rivers in the extent of their drainage. With an annual rainfall of nearly
forty inches, and a general regularity of seasons, few of these streams-and they
only during an occasional severe drouth in the summer-lack abundance of water in
any part of the year.
The geological conditions of the
county have permitted these streams to shape its surface into a network
of tortuous and highly picturesque courses, the characteristics of which vary
from the grandeur of nearly vertical cliffs to he pastoral beauty of the softest
landscape and gentlest windings of a placid stream. In endless panoramic view
are found the most charming pictures of boldly carved hills, of verdant slopes,
of fertile meadows, and luxuriant foliage that well might engage the
artist's pencil. The admirer of nature, however will find the greatest
inspiration along the Delaware. From the point where its limpid waters
first lave the soil of the county at the Durham hills, it flows for
several miles in a tortuous course through a deep and some- times narrow
channel. After leaving the Durham hills the landscape assumes a different
aspect. Here it forms a table land elevated some three hundred feet above the
level of the river, cut out on one or both sides of the valley into long ranges
of perpendicular elevations or extremely steep slopes. One stretch Narrows or
Nockamixon rocks (Pennsylvania Palisades) is an exceedingly grand and
picturesque range of beetling cliffs, rising in places four feet from the brink
of the river, through an extent of nearly three Some of the views here are
strikingly impressive in their grandeur, taken with the river below are
beautiful beyond expression. Tufts of bushes rare botanical plants, and climbing
vines heighten by their green hues
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the rich brown tints of the rocks, and lend to the
bold faces and narrow ledges of the cliffs a grace which nature alone can
produce. There are few more attractive drives or walks than are found along the
river margin at the foot of these cliffs. farther down the river, in the
vicinity of New Hope, some bold ridges of trap-rock impart a pleasing variety to
banks otherwise comparatively tame. At Trenton and Morrisville the river assumes
an entirely different aspect. Instead of a rushing stream vexed with numerous
islands and tumbling over rocky reefs in rapids, it becomes a tidal river,
modified by the flowing and ebbing of the tide. This district is not without
many views of quiet beauty and some that are even grand. The location of Trenton
and Philadelphia in this region has drawn the attention of those who seek a
retired home within a convenient reach of business to the natural attractions of
the lower stretches of the river, and each year marks the addition on either
bank of new residences about which the training hand of art softens the rugged
beauty of nature and adds a charm that even the uninspired can enjoy.
The external relief of a country, however, is only the
expression of its internal rocky structure, moulded by the erosive action of the
elements and the slow chemical influences of the atmosphere. The contour of the
surface indicates the hidden anatomy beneath, and in studying the projections
and outlines of the landscape the inquirer is led to the investigation of the
secrets of its structure. Thus the greater or lesser elevations which are termed
mountains and hills result from the different forms of the strata composing
them. In geological language they are of anticlinal, synclinal, or monoclinal
structure. When it is understood that the larger part of the country owes its
relief to a diffused powerful cutting or wearing action of the elements and
water upon a broad group, or series of groups, of great parallel undulations in
the strata, or more or less compressed waves in the earth's outer crust, it is
apparent that there can exist but three forms of ridges and valleys: 1. Those
consisting of strata bent convexly upward, or dipping anticlinally. 2. Those
consisting of strata bent concavely upward, or dipping synclinally. 3. Those
strata dipping only in one direction, or monoclinally, forming the flanks of the
waves. These three types of geological structure, shared by the valleys as well
as by the ridges, are each of them accompanied by distinctive external forms or
characteristics.
Many interesting examples of anticlinal, synclinal, and
monoclinal elevations occur throughout the county, and it may be well to
recommend to the reader, geologically inclined, to inspect with care such
exposures. They are often met with along the banks of our streams, where lie
will easily detect all the above forms and many other curious phases existing in
the topography of the county.
Few districts of the state disclose the connection between
the 'external physical features of the land and the character and position of
the various
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strata more plainly than certain portions of Bucks county. The position of
the count bordering on the Delaware river embraces within its limits a portion
of the old gneiss ridges of the South mountain, on its northern boundaries, to
the Cretaceous outcrop at its southeastern extremity. Most of its
surface, however, is covered by the Hesozoic new red sandstone and shale,
dipping north, westward at angles varying from nearly horizontal to fifteen
degrees. The apparent thickness of this formation according to the second
geological survey is about thirty thousand feet, which seems incredible for
several reasons; seeing that at halfway of the distance across Solebury and
Buckingham townships, a northeast and southwest fault, ten miles in length,
brings the sandstone No. 1. and limestone No. Il. up to the surface with quite a
limited disturbance of the contour or topography of that section of the county.
The whole surface of the Mesozoic country has been reduced by erosions
several hundred feet at least, as the. deposits must have once overspread the Potsdam-covered
gneiss ridges at the northern end of the county, for they still rise almost to
the top of these ridges (10001 A. Tide). Prof. J. P. Lesley, in his Geological
Atlas of Counties, says in regard to this deposit: 11 Although
they dip north towards (the Potsdam-covered gneiss ridge), and there is no
evidence for a fault; but why no trace exists in the great valley cannot be
explained, except on the supposition that the surface of the valley has been
lowered by erosion at least a thousand feet since Mesozoic times; and
this is proved at Hummelstown in Dauphin county."
The Mesozoic formation is of the same character
throughout, an alternation of hard and soft layers of reddish sand and mud, some
fit for building purposes, some conglomeritic, some calcareous, and some
fossiliferous, containing numerous bones of lizards, shells, and fossil plants.
The name Mesozoic red sandstone, by which this deposit is designated by
geologists, is given to it in allusion to the geological age in which it was
produced, both its organic remains and its position among the other systems of
strata distinctly indicating it, to have originated early in the so called
Mesozoic period, or middle age of extinct or fossil life. As a term, it is less
theoretical and more descriptive than that new red sandstone, the title
often conferred upon it by geologists. In the central and upper parts of the
deposit we not unfrequently meet with dark gray and blue shales, containing much
carbonaceous matter in a partially pulverulent, state, with here and there a
chunk of true compact lignite more or less bituminous, but retaining
distinctly the fibrous structure of the wood from Which it has been derived.
This lignite is even occasionally in continuous layers of two or three inches
thickness, extending for several yards. Approximating to the features of genuine
coal, these little seams are a fertile source of delusive hope among those who
are ignorant of the geological relations of the strata. Besides the foregoing
enumerated characteristics of this great body of red sandstone and shale, the
formation includes, near its north and
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south limits, two other subdivisions which claim a short
description ; these are ooarse conglomerates, very heterogeneous in composition
and interrupted in their line of outcrop. In the east part of the belt,
especially along the Delaware, the base of the whole formation is a mass of
coarse pinkish and grayish sandstones, composed of angular fragments of quartz,
feldspar, and a small percentage of mica, the constituents of the neighboring
gneissic strata. These beds graduate upward into the more argillaceous sandstone
strata. These pebbles are of all dimensions from one-half inch to five or six
inches.
A conglomerate very similar to that which
lies at the base of the formation constitutes in several neighborhoods the upper
or terminal stratum. This conglomerate is so well characterized along the
northwest margin of the formation that it is entitled to be regarded as a
distinct subformation ; it overlies the formation, not in a continuous belt, but
in several Iona, narrow patches. Trapridges and dykes accompany this formation
throughout the county. The rocks constituting them are of igneous origin, and
were ejected in a melted state throuah fissures in the earth's crust. It is
remarkable that these fractures should have taken place in great numbers just
where the formations exist, and only sparingly east or west of them. The igneous
and aqueous rocks are so associated that they necessarily come into the same
history. This geological relationship of the trap to the sandstone is an
important feature of the formation embraced within the limits of Bucks county.
What the physical causes were, which, at the close of the Mesozoic period,
confined the rupturing of the strata and the effusion of trappean matter to the
comparatively narrow area overspread by this formation is difficult even to
conjecture, and the present is not a fit opportunity for speculating, on the
subjects.
In many cases this trappean matter occurs
simply as a narrow dyke. It has come up through fissures in the sandstone, and,
as it escaped, it often thickened up into high elevations; yet nowhere does it
seem to have flowed far over the surface. The proofs that the trap was actually
melted are abundant ; for the sandstone rocks have in many places been baked to
a hard grit by the heat, and at times so blown up by steam as to look
scoriaceous. In some places the uplift has opened spaces between the layers
where steam has escaped, and changed the clayey sandstone into a. very hard rock
looking like trap itself. Occasionally crystalline minerals, as epidote and
tourmaline, are among the results of the baking. The evidences of heat moreover
diminish as we recede from the ridges ; and there is no doubt that the sandstone
has been extensively worn away by waters where it had not been rendered durable
by the heat. The ordinary trap-rock of the Mesozoic belt of Bucks county
is that variety which is known under the rather obscure name of Basalt, and
which in its typical forms consists of a union of augite, feldspar, and
titaniferous iron, the first-named mineral predominating. In some dykes,
however, the rock embraces much hornblende, replacing the augite. It is in such
cases a true
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greenstone trap, but this is the less common variety. It is
of all degrees of relative fineness of crystallization, from a coarse aggregate
to a very complete homogeneous mass. It contains few extraneous minerals, and
these are chiefly met with in the amygdaloid varieties, near the borders of
certain of the larger dykes, or more properly in immediate contact with the
altered red shale, by the reaction of the trap upon which this amyrdaloidal
character has been acquired, and these minerals have been evolved chiefly by
segregation. Some of the dykes of trap along the Nockamixon rocks or
Pennsylvania palisades contain copper ore (copper glance erubescite and
malachite), and there is little doubt that the copper veins and the carytes,
which is often the ganque of the veins, originated in the same eruptive period.
Several isolated masses of traprocks are exposed in Nockamixon township. 11
The Ringing Rocks" occur in this township. Haycock mountain, about
four miles southwest on the same strike, is. quite a prominent feature in this
formation. A range of hills four miles in length in Rockhill township consist of
trappean material. Several trap-hills enter Bucks county from Montgomery county,
near the northwestern corner, another in Southampton township, and several
others occur near New Hope, with others scattered throughout the section covered
by the Mesozoic formation. At the southern edge of the formation its
lowest strata lie upon the Trenton range of gneiss, and appear to be made up of
fragments of the older rocks.
This rock is a coarse reddish-gray quartz,
with occasional strata of conglomeritic sandstone, and is exposed at several
quarries below Yardley. It is composed of small angular grains and imperfectly
rounded pebbles of minerals of the neighboring gneissic rocks, the upturned
edges of which it rests upon unconformably. The pebbles are chiefly quartz and
feldspar, those of the former mineral being in certain layers nearly an inch in
diameter. Some of this quartz is slightly opalescent. Much of the feldspar is of
a dull yellowish color, without any lustre. A certain amount of hornblende and a
small proportion of mica likewise occur. Dispersed among these materials, we
find minute specks of yellow hydrated peroxide of iron ; this substance and the
disintegrated feldspar weaken the cohesion of the rock, and greatly impair its
value for building purposes. The bedding of the layers is not very regular, the
restilt of inclined deposition, a structure which materially injures the utility
of this rock for many purposes. The lower member of the formation is traceable
under more or less distinctiveness of character for many miles from the
Delaware, but in places extremely narrow.
Above these heterogeneous rocks or lower
formation there rests a series of beds of a somewhat different material,
constituting a zone which near the Delware ware is several miles in width. In
this division the predominant rock is a rather coarse-grained pinkish sandstone,
composed of transparent quartzose sand, specks of feldspar, and occasional flat
pebbles of compact red shale, or
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sandstone; but the siliceous sand is the chief ingredient, and
the cement is the red shale or clay. From the circumstance that no part of the
formation bag ever been deeply buried, either under a great mass of waters or
beneath other strata, the cohesion of these rocks is not very great ;
nevertheless this belt furnishes some of the best building stone derived from
the whole formation. It is quarried near Yardley, and for some distance above
and below, and in New Jersey. In a series of quarries along the canal it may be
noticed that the stratification is for the most part regular, and the rock is
easily quarried and wrought. The next overlying division of the general stratum
is much broa4er, extending from the last described to a point about a mile north
of New Hope to a tract or an exposure of limestone in Solebury township. All
forms of these rocks exist in this division from the soft argillaceous shales to
bard siliceous and micaceous sandstones. These strata having here a
west-southwest strike range through the southern half of the county, entering
Montgomery in the same direction. In the neighborhood of the Delaware river,-
several immense dykes of trap-rock appear, the heat of which has caused
extensive alteration in the aspect and appearance of the strata, and developed
some interesting phenomena of mineral segregation. The most corhmon minerals
thus elaborated are epidote, phrenite, zeolite, stilbite, etc. In the vicinity
of Centre bridge there lies a diversified series of strata of about one mile in
width, which consists of red standstones and coarse yellowish conglomerates,
divided by occasional thinner beds of soft red shale. These strata much resemble
those found at the base of the formation. Much building stone is quarried in the
vicinity of Centre bridge, the stone being well adapted for that purpose.
Passing northward along the Delaware the red shale rocks are found extensively
altered by the temperature originally imparted to them by the trap-dykes, and by
igneous rock which has not reached the surface, but of the close proximity of
which there exist the strongest indications. The tract under consideration, near
the Tohickon creek, consists of partially metamorphosed strata, compact and of a
prevailing dull brown color, sometimes passing into a dull blue, and are
intersected by large joints into rhombie blocks. Those portions which have been
subjected to the greatest amount of igneous action have a semi-crystalline
feature, and when struck give out a ringing sound. The Nockamixon cliffs
along the Narrows possess the same peculiarities.
The red-shale country is rather fertile and
well cultivated; but those portions of red shale where the rocks are changed to
a dark-bluish or purplish color have usually a wet, heavy soil, and are not so
much esteemed for agricultural purposes. Many interesting matters connected with
the great Mesozoic belt are of necessity passed over for want of
space.
Turning now to the southern end or line of the
Mesozoic where it flanks the metamorpbic rocks, it is observed to extend
from the Delaware river, commencing about midway between Morrisville and
Yardley, across the county, entering
Page 57 Picture (Notices: after each
picture the next page is blank)
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Montgomery county several miles south of Southamptonville.
There is here no well-defined escarpment, the red soil which results from the
decomposition of the red shale being the only guide. Between the Delaware river
and the Montgomery county line the Mesozoic rests upon and overlaps the Syenites.
The boundary of the Mesozoic and the syenites is very
irregular, owing to the irregularity of the latter and the erosion of the red
shale. The syenitic and gneissic rocks of the Laurentian group extend
along the southern border of the Mesozoic formation from the Delaware
river to the Montgomery county line, extending into that county along that
formation for some distance. The character of the rock is similar to that of the
Durham hills.
Small particles of magnetite have been found in many
localities, but no ore of any amount has yet been discovered here.
At A. Johnson's farm, southeast of Feasterville, plumbago has
been found in a single locality, but not in sufficient quantities to encourage
mining operations.
Crystalline limestone occurs in a local deposit at Van
Artsdalen's quarry in Southampton township.
South of the Syenitic belt of rocks appears the Potsdam-
Sandstone group of rocks, extending in the same direction across the county
as the Laurentian rocks. The Potsdam rock is a fine-grained
sandstone with micaceous partings, occasional beds of coarse sandstone and
conglomerate, and beds of quartzite. Tourmaline crystals are numerous, usually
of a small, needle-like shape. Iron pyrites are plentiful in nearly all
localities. Cavities are often met with where this mineral has been weathered
out of the rock. There are many exposures of this rock along its trend, forming
in many places quite prominent ridges, especially in Falls township. The Potsdam
formation is well exposed at Neshaminy falls, in Middletown township. The
dip of the rock varies greatly. In Southampton township, near Neshaminy falls,
along the southern margin of the sandstone, there is a well-defined escarpment
between the Syenites, Potsdam, and mica schists.
The mica schists are flanked on the north by the Potsdam. There
are numerous exposures of this rock along the Neshaminy above Hulmeville. The
rock along the northern edge of this belt is a garnetiferous mica schist.
Proceeding southward the garnets gradually diminish in quantity and give place
to mica schists and quartz. Alternations of hornblendic slate occur in the
garnetiferous belt.
The southern end of Bucks county is occupied by a belt, five
miles wide, of Philadelphia rocks, micaceous gneisses, and mica schists of
unknown age, dipping gently northward and covered with gravel of recent but
various ages, ending with the present river mud. A straight and steep outcrop of
the Edge Hill sandstone along the south edge of the older gneiss
separates it from the Philadelphia gneisses and schists.
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Professor Charles E. Hall says in regard to these mica schists: "We encounter the same difficulty in
assigning the mica schists and gneisses to any place above the Primal
(Potsdam Sandstone, No. I.) until we get above the horizon of Rogers's Aurol
limestones, No. 11. The dividing line between the deposits of the Potsdam
and the limestones is sharply defined, the change of conditions was rapid,
and the source of material was changed. And there are no intermediate deposits
of mica schists and gneisses which might be equivalent to the first and second
belts But towards the close of the deposit of the limestones the conditions were
quite different. Throughout the upper portion we find the limestones alternating
with slates. Beds of slaty limestones and slate are met with occasionally in the
middle and lower portions ; but as we ascend the limestone gradually becomes
subordinate and the slates predominate.
"These slates (which have been called the South
Valley Hill hydromica and chlorite slates) were considered by Professor
Rogers as equivalent to his Primal of the North Valley Hill; which is
not possible, for the Potsdam sandstone on the north meets the limestone
only a few thousand feet from the south side of the valley where the South
Valley Hill slates occur. There are no transition measures between the
limestones and the slates of the South Valley Hill. Now, if we assume that the Potsdam
in the north hill and the slates in the south hill belong to the same
horizon, it would follow that there was a belt a few thousand feet wide,
extending from an abrupt commencement near the Schuylkill, southwestward beyond
the Susquehanna river, along the southern side of which a gradual change or
transition took place, and on the north side of which the change was sudden or
spontaneous. Such an argument is unreasonable. The structure alone is sufficient
to prove that these slates of the South Valle ill are not altered Primal but
no other than a series of slates
"Aside from the paleontological evidence there is
sufficient proof of their Hudson river age alone from the structural relations.
The lower portion of this South Valley Hill belt shows a gradual transition from
limestone to slate deposits. Throughout the lower portion of the group there is
nothing resembling the gneisses and mica schists of the lower Schuylkill (first
and second belts of Rogers). It is therefore far above the base of the South
Valley
In the, southeastern part of Falls township there is a small
area of clay exposed. This appears to be a remnant of the lowest clay beds of
the New Jersey Cretaceous. The clay is capped by gravel and forms a
prominence known as Turkey Hill. It is surrounded by alluvial deposits, and the
exposures are confined to the flanks of the hill. The same clay is exposed in
The course of the Delaware river here points to the fact that
the stream has been gradually cutting the edge of the formation, which at one
time extended
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History of Bucks County By J.H.
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