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

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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


History of Bucks County By J.H. Battle  Table of Contents