The oil regions of Pennsylvania

Front matter

\ LIBHARY OF CONGRESS.

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♦UNITED STATES OF AMERICA,

Chapter I. Physical Features And Geology Of The Country

The physical features of the oil region of Pennsylvania are simple, easily understood, and full of interest. The most productive portion of it consists of an irregular quadrangle, each of its sides being from fifteen to twenty-five miles in length, and its axial line nearly corresponding with the course of Oil Creek between Titusville and Oil City. As far as known, it is limited almost exclusively to the Alleghany Eiver valley and a section of its north-western slope, the principal streams which enter it from that direction having an average fall of about twenty feet to the mile, while that great artery of Western Pennsylvania, between "Warren and Pittsburgh, has an average fall of one foot to the mile. At Franklin, the mouth of French Creek, it is nearly eight hundred feet above tidewater, or two hundred and forty feet higher than the surface of Lake Erie. The lake shore proper is a comparatively narrow strip of land, descending from the range of heights which separate it from the Alleghany slope, by frequent and abrupt terraces, to the water. In the opposite direction the descent toward the south-east is for a long distance so gentle as scarcely to be noticeable along the water- courses. The country is nearly level, or rolled up into hills of moderate elevation and easy ascent. Such is its general appearance immediately back of the oil region along the line of the Atlantic and Great Western Railway.

On leaving Corry for Titusville, the passenger is conveyed up a rather steep incline for a few miles, on passing which the railroad traverses the summit, a table-land with occasional ridges of very moderate height, or round hillocks formed of drift — that is, sand and boulders, ground, rounded, and more or less polished. By and by the road enters a slight depression, which increases till it becomes a ravine, and finally the bottom of a noisy stream, with banks twenty, fifty, and finally one hundred and fifty feet high, at which it reaches Titusville. The railroad extends down the valley seven or eight miles further, the heights on each side becoming more lofty and precipitous, until, at Shaffer's, they reach two hundred and fifty feet, and at Oil City, twelve miles lower, nearly four hundred feet above the Alleghany River, the difference in their summits being inconsiderable.

The approaches to that river by the railroad from Meadville to Franklin, and by that from Corry to Irvine and Warren, are still more simple than on the route already described, there being no elevations to be climbed before reaching the descent ; but a gentle, downward grade for the entire distance. Starting from a nearly level country, however, the same phenomenon is perceptible as on the Titusville road, namely, heights gradually increasing in altitude and abruptness, until the common objective point

(the Alleghany valley) has been reached, where they are found at about the usual elevation of four hundred feet.

Starting from that river in the direction of the Alleghany Mountains, along any of the tributary streams which flow through that part of the country, an exact counterpart to this formation will be found, for the twenty, thirty, or forty miles immediately east of the Alleghany.

Not alone in the oil regions of Pennsylvania will this observation be found to apply. The same physical features are noticeable in "Western New -York, West- Virginia, Eastern and Southern Ohio and Indiana, and Northern Kentucky — in fact, throughout the entire prairie States, along both sides of the Mississippi and the Missouri. Whatever may have been the cause, it is evident that agencies essentially alike have been at work in producing the effects visible to-day.

The observant visitor will notice, further, that all this is accompanied by hardly a perceptible inclination or " dip " of the rocks, which, as high up and as far down as he can trace them, are disposed in beautiful horizontal lines, gray, yellow, or brown sandstones alternating with blue, red, or brown shales, in regular and frequent succession. At no point will he detect " faults " or dislocations in the arrangement of these, whether on the surface or beneath, nor will he find the inclination at any point exceeding five degrees. If he has read or observed carefully the structure of mountains elsewhere, he will remember that the rocks are tilted up at various angles with the horizon, in some cases almost ninety degrees ; while at every few paces he can discern marks of disturbance in their situa tion with respect to each other. He will begin, perhaps, to reason within himself how very improbable it must be that those heights could have been individually upheaved, inasmuch as thej evince no signs of such action, having no inclination save that south-eastern or south-western dip common to all the formations from Lake Ontario to Kentucky and Tennessee.

If he climb the heights, the mystery at first may increase ; for while toward the principal streams the bluffs are usually abrupt, precipitous, pyramidal, or ridgy ; on looking in the opposite direction, he will observe the same table-lands; with gentle elevations formed of drift here and there, such as he encountered between Corry and Titusville. *Ke can hardly fail to suspect the truth, that the river-beds, with all their tributaries and the bottoms of ravines, have been, in the course of ages, scooped out of very slight original depressions by the action of water, which has dug out these vast channels to their present depth, and is still engaged in deepening and widening them.

This is the view taken by all geologists of eminence, who have examined that portion of the State. Professor Vm. D. Eogers, in his admirable Geological Report, says : " The Alleghany flows through a deep and narrow trench, excavated in the north-west plateau, and within the coal-basin of the State. ... It enters the north-western margin of the coal-basin at Warren." . Eeferring to the remarkably irregular course of that river and the Ohio through Pennsylvania, he further observes : " It is evident that while the main discharge of the eroding wave was south-westward, one large influx of eroding waters swept north-westward from the Apalachian Mountains, and another south-eastward from the region of the lakes."

The expression "eroding wave" must not, however, be understood to imply that, by a single deluge, whether lasting a day or a twelvemonth, the troughs in which those rivers now run could have been hollowed out. JSTo single accumulation of waters, collected on the Apalachian Mountains or in the lake basin, would be sufficient to excavate those valleys to the depth of a single inch, much less hundreds of feet. The joint action of time and water was necessary to "write those wrinkles on the brow" of that Piedmont section ; and of the former it would be silly to assign less than myriads of our years. It is true that in an earlier stage the denuding process would go on more rapidly, inasmuch as the mouth of the Mississippi was several hundreds of miles higher up than at present; while the Ohio and its tributaries, flowing down from the table-lands, would rush forward and abrade their bottoms and banks at a rate which can hardly be understood at present. The hard limestone bed crossing that river at Louisville has prolonged resistance till this day ; but that is also destined to wear away, together with the softer rocks above ; the fall or rapid thus, step by step, retreating to Pittsburgh, unless prevented by artificial obstructions.

Along the Ohio, as it passes between Pennsylvania, West-Virginia, and Kentucky, on one side, and Ohio and Indiana on the other, it may be observed that while there is substantially the same horizontal stratification, with abrasion of the uplands, the action there has been on a still larger scale than further northward. The causes of this difference are unquestionably to be found in the circumstances of the larger bodies of waters at work lower down, and the beds of rocks forming the upper series along the Ohio consisting of soft shales, which readily dissolve, and, in places, are so constantly crumbling away as to form little streams of gravel, which become beds of stiff clay or mud upon reaching the bottoms. This is carried off in immense quantities every year, on the melting of the snows and after rains, to the Ohio, the Mississippi, and the Gulf, to form fresh additions to the area ot Louisiana, or some other of the Cotton States. For the whole of the sugar region, and at least one half of the cotton, rice, and tobacco zones of the South consist of alluviums, carried down the eastern and western slopes of the Apalachian and the Eocky Mountain systems, along rivercourses, whose beds have been carved tens and hundreds of feet below what was once the general level of the country.

In the oil region of Pennsylvania, the uppermost rock in the series (vespertine) is a hard, gray conglomerate, which resists the action of water until undermined bv the dissolution of the soft shales underneath. When this has been brought about, down tumble huge masses of the vespertine, in uniform and often quadrangular blocks, which in turn become the natural protectors of the bases and sides of the bluff, as they had been of its summit. But for these efficient safeguards, it is reasonable to infer that the channels of the Alleghany and some parts of the Ohio would have been as wide as they are found elsewhere, particularly near the mouth of the latter, where the country for miles on each side has been washed away.

This explanation of the origin of those valleys finds abundant confirmation at every bend in the streams, particularly the large ones. In proportion to the sharpness of their curves is the precipitous character of the hills forming their exterior lines ; while on the opposite side, the heights slope gently and gracefully to the water. Almost the only fields cultivated on the slopes are those headlands around which the river describes a semicircle. On rivers flowing through alluvial countries, as the Potomac and the James, the same rule will hold good, as to the areas embraced within their several bends or loops, while the opposite shore will invariably be found lofty and abrupt, the channels keeping well outward, as if desirous of increasing their circuit, instead of proceeding " on interior lines " or cut-offs. The phenomenon is thus explained : Like all other bodies, water has a tendency to move in straight lines, as have all the objects which move upon or are carried down by it. At every bend, for example, the raft is naturally thrown somewhat out of the middle toward the convex side of the river, and the shore there is struck with all the weight and momentum of the current, until it is undermined, when the portions lying highest up fall down and are gradually ground up and their particles carried off, making room for the water to renew its action upon the bluffs. Hence the two processes of lengthening and deepening the stream may be said to go on pari passu. At the principal bends, the river, which at one time flowed on a bed hundreds of feet higher, also described hundreds of yards of a shorter course than it now does.

As it deepened in one direction, it struck outward in another. During century after century, it thus kept forsaking its old channel and entering one more crooked, rounding the headlands, which were afterward covered with surface soil washed down from above, or made by vegetation on the spot. Every mile or two along the Alleghany, Oil Creek, French Creek, etc., these additional evidences of erosion or denudation become manifest in the formation of the river-beds. The unavoidable inferences are, that the depositing of oil, or the constituents composing it, has had no possible relation to existing river systems; that curves, headlands, slopes, table-lands, and bottoms, have no connection, as such, with the finding of petroleum ; the only cause why it was discovered in the last-named being, that that which was stored in the first sand-rock beneath the surface could more readily find its way to it in localities where the deposit had been approached to within short distances. It was only because it could come more easily to the surface in springs along the river-bottoms than on the uplands, that it was originally discovered in the former ; but on the latter, the veins in the second or third sand-rocks, which are unable to manifest themselves above ground, are quite as likely to be reached as on the former, the only drawbacks being the greater cost of boring and of pumping the wells afterward.

Though rather foreign to the subject discussed in this work, I may add, that the views advanced above explain the cause why " cut-off" canals, as those at Yicksburgh and Dutch Gap, have been unsuccessful. They were dug at points too far down-stream, with their upper extremities some distance below the bluffs, against which the current had struck and been deflected toward the opposite bank. Had General Butler's famous work taken "the line ot beauty," its northern terminus opening against the channel as it struck the bank, there could hardly be a doubt of its success. - »

If the length of time required to effect • such changes on the earth's surface be bewildering, our wonder will not subside on inspecting more closely the several strata between the uplands and the lowest point yet reached by the drillers, a range of about fourteen hundred feet. Marvels, indeed, never cease in Petrolia, whether we regard it

Physical Featwres^ etc. 17

in its natural aspect, or its lately developed condition. If we take our stand on any of the elevations along Oil Creek, French. Creek, the Brokenstraw, or any other tributary of the Alleghany, in that quarter, in the masses of gray, brown, or flaggy sandstones, even on the conglomerates forming the uppermost rock in the series, we shall discover multitudes of the impressions of what once was vegetable or animal life — shells univalve and bivalve, shells of all shapes and sizes, rough and smooth casts of shells. The plants belong largely to a species known among naturalists as fucoids. The organic remains of the shell-fishes indicate that they lived and moved in salt, not fresh, water ; that they died a natural death, the consequence of ordinary decay, closing up the doors and windows of their abodes, and quietly dropping to what had been their couch e're it became their cemetery — the ocean-bed — as composedly as Caesar wrapped himself up in his toga, at the base of Pompey's statue. Nothing out of the natural course, no marks of violence are perceptible in the circumstances attending their dissolution. ]So deluge appears to have swept them away five hundred or one thousand miles from their native settlements to end their existence on the tops of the mountains.

" Once, in the flight of ages past,

There lived a crab ; and who was he ? Mortal, where'er thy lot be cast, That crab resembled thee !"

This testimony is not confined to one rock or series in the several geological formations of Western Pennsylvania. In the numerous layers of sandstone, slate, shale, clay, and soap-stone, evidences of mineral and vegetable life may be found as low down as the beds of the streams, and hundreds of feet beyond. At different points on the railroad between Meadville and Franklin, the rock- cuttings pass through what once were dense forests of tall trees, the petrified ends of their stems projecting through the soft layers, which are beautifully bent around them, the petrifactions lying in places as closely together as they could have fallen.* Their diameters range from ten inches to three feet. The pores of the bark are still visible, as is its general arrangement on the outside of the quondam trees. The grooves on the exterior, the layers of the interior, with several of the lines radiating from the heart, are still observable. These petrifactions may be found at various depths, from ten to forty feet below what is now the surface of the height, but which was hundreds of feet below it previous to the eroding action of the waters. Shell-marks in abundance are discoverable in the lowest of those rocks, as in all the intermediate strata. Mr. A. Morrell, now of Titusville, an experienced operator and a careful observer, assures me that the sand-pump has brought up, from the depth of four hundred and eighty-five feet, specimens of petrified shell-fish, which are now in his possession, having been obtained in a layer of hard, fossiliferous limestone, termed by most operators, " the third sand-rock." Here we have an aggregate thickness of fully seven hundred and fifty feet, containing probably twenty distinct layers, in most or all of which the remains of vegetable and animal life are discovered. Should it turn out that the Niagara limestone underlies that re-

* The remains of a mastodon are said to have been discovered in that vicinity, while the railroad was being graded.

gion, there is no telling how many hundreds of feet lower such remains may yet be discovered.

The groups of sandstones above the river-beds differ somewhat in various localities, one of a coarser texture being replaced by a finer, or the opposite, a pure sand-rock, by one more or less argillaceous, a gray by a yellow-colored conglomerate, containing pebbles of quartz, sienite, gneiss, etc. In some places they afford excellent materials for building purposes ; in others they are made into grindstones ; superior flag-stones are to be met with everywhere. But such are mere local variations, brought about by the deposition of the several materials of which the layers are composed. In general, it will be found that they belong to rocks which terminate toward the north in the State of ISTew- York, and, in South-western Pennsyvania and West- Virginia, are found hundreds of feet below the surface, the several coal-formations, with the intermediate layers, being there superimposed on these formations. Counting downward, in Yenango county, the following is the succession which most frequently occurs :

1st. Vespertine conglomerate and sandstone. This is a white, gray, or yellowish rock, varying in texture, and alternating with a coarse, silicious conglomerate, or with dark-blue and olive-colored slates. In places it contains beds of dark, carbonaceous shales, with thin seams of coal. Among its organic remains are numerous fragments of coal-plants. In some parts of the State this series is found of immense thickness — as much as twenty-six hundred feet, according to Professor Kogers, near the Susquehanna Eiver. In Yenango county I have not observed it more than one one hundred feet deep, and seldom more than fifty. " This group has a wide distribution in Pennsylvania, encircling as with a sort of girdle, all the coal-fields, both anthracite and bituminous. ... It undergoes gradual but important changes of type, growing thinner, and assuming a finer and finer texture in its materials, as it spreads westward. Its orographic position is on the ridges and external escarpments of the table-lands, which enclose or support the coal-fields ; but, except in the north-western district, it does not immediately adjoin the conglomerates and sandstones of the coal-measures. . . In this north-west belt, and along the north side of the State, it is a somewhat argillaceous, micaceous sandstone. . . An absence of fossils, and a close assimilation of the vespertine and umbral series render it difficult to define their common boundary. . . Around Warren, this group of rocks, reposing directly on the vergent series, and overlaid by the serai white sandstone, consists of four members — the lowest a group of thin-bedded sandstones and olive-gray shales, the sandstone containing a perpendicular, bifurcating, stem-like fossil. The second is a massive quartzose conglomerate of smooth, ovoid pebbles, about ten feet thick. The third is a thick mass of olive-gray shale and thin-bedded sandstones, about one hundred and seventy -five feet. The fourth, or uppermost, is a fossiliferous gray sandstone, from ten to fifteen feet. . . The vespertine conglomerate caps the hills north-west of the Alleghany Eiver. It is often mistaken for the serai conglomerate and sandstone of the coal measures." (Kog-eks.)

2d. The vergent series. This consists of a rather finegrained gray sandstone, the layers parted by thin alternating bands of shale. According to the authority just quoted, it abounds with remains of marine vegetation. In Huntington county it attains a thickness of seventeen hundred feet. In Yenango county it comes down to the river bottoms, a distance of nearly three hundred feet below the vespertine rocks ; how far beneath the valleys is unknown. Toward the west this series has a wide extension, spreading out in Ohio, in Kentucky, and even Middle Tennessee, as well as stretching through West-Yirginia and East-Tennessee. Some geologists have classified this series as follows, counting downward : Slate and flaggy sandstone. Two layers of hard, silicious sandstone. Beds of thin, pebbly rock. In places, a stratum of yellow sandstone. Several beds of gray sandstone, of more or less thickness. Two or three thin layers of sandstone, with shells. Beds of shale, usually very dark, alternate between each of the above-mentioned layers.

This second series comprises what are known in New- York as the Chemung and the Portage groups. They belong to the class denominated palceozoic rocks, because containing the most ancient remains of animal and vegetable life yet discovered, stretching all the way between the gneissic formations beneath, and the lowest of the coal-deposits above. Sometimes they are denominated, " fossiliferous," "sedimentary," or "secondary" rocks. "In Pennsylvania," says Kogers, "this class have been deposited during all the four earliest periods of the great European divisions, namely, the cambrian, the silurian, the devonian, and the carboniferous. No traces of the fifth or permian group have yet been discovered in North- America. . . . The prolonged succession of sedimentary action ceased with the close of the cambrian system, being terminated by the upheaval of the ocean, in whose broad bed, and around whose margin these deposits had been collected." The aggregate thickness of all the rocks belonging to this class, measured at their greatest depths, is not less than thirty-five thousand feet.

As mention has been made of the coal-beds found in that vicinity, and as the coal and petroleum formations are generally believed to be intimately related to each other, both being largely carbonaceous, it may be proper to remark here, that the oil region is bounded by the coal-fields, on the south and the east. On both sides of the Alleghany, near Franklin, coal crops out, in a thin bed, and of a rather poor quality, along the summits of the hill, from two hundred and fifty to three hundred and fifty feet above water. Farther down the river it occurs at a lower elevation, until on reaching Pittsburgh the deepest beds are found below the water-courses. In some localities near Franklin, the coal- vein appears to have filled a cup-like depression once existing on the surface where it was formed, the bed now dipping downward, and afterward rising to its former level. In that neighborhood the coal-bed may be traced as a dark, even line, extending along the highest eminences, while at the foot of the bluffs operations at boring have been going on. Toward the east the coal-fields are more distant ; but their margin in that direction has not been clearly traced and defined. Owing to the absence of large streams and broad bottoms, operations at searching for petroleum have also been greatly restricted east of the Alleghany. The nearest practicable point at which coal can be reached is on the line of the Philadelphia and Erie Eailroad, above Warren.

As far as I am aware, no actual test has yet been made, or if made, none has succeeded, in boring for oil through the coal-measures. The experiment is one that ought to be instituted, its results haying something to do with verifying or disproving the theory as to the genesis of petroleum commonly entertained. By some it is stoutly maiatained that the one is never found immediately above or below the other ; hence, that it is idle to expect oil on coal-lands. Others assert that they have, in West- Virginia, passed through the coal, and found oil beneath. It devolves upon the owners of coal-lands to prove the contiguous existence of the two, or else be satisfied with lower prices than they are now demanding.

At all events, the two formations in Pennsylvania are geologically separated by great distances. Between the coal-beds and the first sand-rock where oil appears, at least four hundred feet intervene, and at least eight hundred feet between the coal and the third sand-rock, from which the largest yield has been derived. As to the possibility of the one being supplied from the other, some further remarks are offered elsewhere.

Descending to the formations helow the river-bottoms, as traversed by the drill, and brought up (as mud) by the sand-pump, it becomes necessary to take the " records" of wells as kept by operators of more or less acquaintance with the subject. Mr. Morrell gives the following as the series found on the Watson flats below Titus ville, in sinking five hundred feet :

First. Schist rock, with mica and a little hornblende. This is what the drillers usually term " the first sand."

Second. A very soft, silicious rock, resembling soap-stone. Feels very soft and greasy at first, and has a nearly white color ; but hardens, and becomes bluish after a time.

Third. A hard transition rock.

Fourth. Fossiliferous limestone, containing fissures 01 caverns in which oil is found. This is usually termed "■ the second sand-rock ;" and as it contains sand in various proportions, it will be so termed in this work.

Mr. E. B. Gamble, also of Titusville, who is superintendent of the Pennyslvania Oil Creek Company's Deep well, (now fully twelve hundred feet below the level of the Watson flats, and still in progress,) furnishes the following as the results of his observations :

The first sand-rock commonly occurs there between one hundred and fifty and one hundred and sixty feet down, and is about sixteen feet thick. Drillers then bore through different layers of slate and soap-stone, (not the common variety of the latter,) in which the tools often stick fast. Between four hundred and eighty and four hundred and ninety feet, they strike a pebbly bed, often mixed with slate, and usually five feet thick. What is known as the second rock occurs about four hundred feet down, and is between fifty and sixty feet thick. In this bed, oil is most commonly obtained in that locality. In this particular instance, the company decided to keep on boring for the purpose of making an experiment, with the annexed result : At twelve hundred and fifteen feet, they had not reached the third sandstone ; and the general belief among practical men on the flats is, that none such is to be found there. But they passed through shale, slates, soap-stone, etc., as above the second layer. This well is, at least, four hundred feet deeper than any other whose record I was able to examine.

In passing, it may be mentioned here that a company has been formed at Petroleum -Centre, with Mr. D. W. Davies as superintendent, to sink a shaft, about seven by seventeen feet, as far down as practicable. The organization is known as the Shaft Company. The experiment cannot fail to be highly valuable to the cause of science, and may repay all outlays upon it one hundred times over. Every company and land-owner in Petrolia ought to encourage the attempt. The evolution of gas will constitute the chief difficulty to the progress of this undertaking ; and may prevent the introduction of artificial lights altogether. As, however, it is much lighter than common atmospheric air, it is believed the latter can be forced down in quantities sufficient to render the operations innocuous. Much interest will attach to the work as it progresses.

Mr. T. S. Truaire, a refiner and a gentleman of veracity and much intelligence, furnishes the subjoined statement from his record of a well, sunk under his direction, one mile above Oil City : " At the depth of two hundred and five feet, we struck the first sandstone, and went through it at two hundred and forty-three feet. From that point to three hundred and fifty feet, we found hard-pan clay, beyond which we struck the second rock, thirty feet thick. From three hundred and eighty to four hundred and fifty feet, we found another shale ; and on passing this, we entered the third sand-rock, of forty feet in thickness. In this we struck a seventy -barrel well."

The points selected above are nearly eighteen miles apart, or fifteen in a direct line, the difference in elevation between their surfaces being nearly two hundred and fifty feet. It is reasonable to conclude that, while the underlying rocks are nearly horizontal, the layers in some places disappear altogether, and in others are modified, both as to quality and thickness. . Several persons report that on the Watson flats, immediately above the oil-vein, they find a hard, flinty rock, a few feet in thickness, black 2 and smooth, like that used for whetstones. Others report rinding a mud- vein, from three to five feet thick, in the very heart of the second rock. It is supposed that this has settled as a sediment, where oil and gas formerly existed, after exhaustion of the former. Whatever the origin, it is productive of much trouble and loss in boring.