Chapter IV

GEOLOGY AND MINERALOGY*

Definition – Anticlinals and Synclinals – Geologic Column – Surface Rocks – Measures- Freeport Group – Kittanning Group – Ore and Limestone – Analyses- Clarion Group- Brookville Coal – Homewood Sandstone – Rocks Beneath – Other Minerals -Petroleum- Theories – Natural Gas – Fuel Value.Definition — Anticlinals and Synclinals — Geologic Column — Surface Rocks — Measures— Freeport Group — Kittanning Group — Ore and Limestone — Analyses— Clarion Group— Brookville Coal — Homewood Sandstone — Rocks Beneath — Other Minerals —Petroleum— Theories — Natural Gas — Fuel Value.

NO work treating of a region so rich in mineral deposits as is Clarion county no would be complete without its geology. To the uninitiated this science with its learned terms and technical expressions is largely a sealed book. It would be a thankless and inappropriate task, in exhibiting local features, to attempt an exposition of its fundamental and most recondite department, viz., the origin and formation of the strata. It will suffice to take them as we find them and sketch their character, their effects and their positions, absolute and relative. We shall strive then to render this chapter on the geology of Clarion county not altogether uninteresting to those who have the merest inkling of the science. Geology is the science which treats of the origin, structure, and position of the rocks and minerals which form the hard crust of the earth. This crust is composed of many distinct beds, or strata, which lie at almost every angle (when not horizontal) with the plane of a small circle passing through the earth and forming an imaginary base. In many places where the strata originally lay in the normal horizontal, an upheaval has tilted them out of their true position so as to form a local bend or ridge. This is an “anticlinal,” and its inclination is called the “dip.” The anticlinal axes commonly lie in groups, and run parallel to and at comparatively short distances from each other. The intervening basins, or troughs, are the “synclinals.” In studying anticlinals we must consider them apart from the topography of the surface, which has no conformity with them and is rarely affected by them.

Anticlinals — Five anticlinals traverse Clarion county northeasterly at an angle of about 40 degrees, and with consequent northwest-southeast dips which, for convenience, we shall call by the greater inclination, viz., east and west. They have been named by the State geologists after localities in this or adjoining counties through or near which they pass.

Beginning at the west the first anticlinal is the Millerstown, crossing the Allegheny a mile below Monterey, the Clarion at Callensburg, passing near Lucinda, and leaving the county near its northeastern extremity in Farmington township; its total western inclination is only forty feet or less. West of some minor axes accompanying this anticlinal there is a Millerstown synclinal, and west of this there are slight local rolls and basins, but no well-defined anticlinal. About four miles east of the Millerstown ridge we reach the axis of the trough of the Brady’s Bend synclinal. Professor Lesley, State Geologist, ascribes the curious bend of the Allegheny to the influence of this flexure. He explains as follows: After the river, flowing southwestwardly down the dip, met the resistance of the opposite side, it ate its way for a short distance into this; but was finally turned back westward to the opposite side of the trough, only to be directed again to the south, where it finally pierced the ridge. In the same manner the Millerstown anticlinal caused the bend at Callensburg. This synclinal, after passing a mile east of Sligo, touches the corner of Monroe, township, passes a little to the east of Clarion, traverses Highland, underlying Scotch Hill, and enters Forest county two miles north of Cooksburg. It is a rather shallow and slightly-marked basin.

Brady’s Bend Anticlinal — This is one of the best-known axes in Western Pennsylvania, and has been traced from the Ohio River. It enters the county near the mouth of Redbank Creek and courses northeastwardly, at about north 36° east, through Madison, Monroe, Clarion, and Mill Creek townships, leaving Rimersburg. and Reidsburg a little to the west and Cooksburg to the east. It has a western dip of thirty five feet to the mile, in the average, though sometimes much steeper; its eastern fall is about the same.

The Lawsonham synclinal is a gentle basin which, as its name indicates, begins at Lawsonham, truncates the corners of Madison, Porter, and Monroe townships; passes through Limestone, Clarion, and cuts the southern end of Mill Creek township. It is difficult to detect its western rise, but it has a marked eastern one.

Next in order is the Kellersburg anticlinal, which has a steep ascent to its crest-line. This passes the Redbank near the dividing line between Madison and Porter townships. It passes near Frostburg and through Greenville, entering Jefferson county from Mill Creek; it becomes obscure after leaving Limestone township.

A gradual dip for a distance of two miles, which is the approximate length of all these anticlinal slopes, brings us to the Centerville synclinal. It is a shallow basin entering the county a little to the west of the mouth of Leather-wood Run, and passing out a mile north of the lower corner of Mill Creek township.

There is only a total rise of forty feet to the Anthony’s Bend anticlinal, but it has a sharp decline to the Fairmount synclinal, averaging about seventy feet to the mile. From near Anthony’s Bend this ridge passes through the vicinity of St. Nicholas Church and enters Jefferson county a mile north of Corsica.

The course of the Fairmount synclinal is through Redbank township from the mouth of Town Run, and across the corner of Limestone. Its western dip, as before mentioned, is steep, but on the east it ranges from twenty to sixty feet per mile. It crosses the Redbank again at Troy, but beyond that becomes very shallow and scarcely recognizable.

The last of the series in Clarion county is the Brookvitle anticlinal, which enters the county near Patton Station and, truncating the southeast corner of Redbank township, soon make its exit into Jefferson county. It has a steep western dip, raising the ferriferous limestone 350 feet above railroad level.

The effects of these alternate elevations of the rock strata is most strikingly and familiarly seen in the variations of the coal veins which are pitched now high, now low, in a manner otherwise puzzling. A good instance exists in the mines of Catfish and Redbank, both on the Allegheny, and the latter place, being down the river has, of course, a lower elevation. Yet the veins at Redbank are seventy feet higher than at Catfish. The explanation is that Redbank is near the crest of the Brady’s Bend anticlinal. Besides these local inclinations there is a gentle southwest-by-south dip of the strata over the whole surface of the county.

Surface Measures — Measures, groups, and series are terms indifferently used by geologists to denote divisions of rock composed of several layers, but all partaking of some common attributes or constructed by similar action. They are named after some salient characteristic, place of best exposure, or some particular stratum embedded in them. Thus the Conglomerate series is so named from the structure of some of its rock layers, which are composed of particles or pebbles cemented by some foreign substance, usually silica or clay. The origin of “Coal measures” is obvious. We append, in order, a portion of the geological column of Pennsylvania, or the outcropping rocks existing in the State. The table begins with the highest:

There are seven series yet beneath these. Of the above list the following form the surface of Clarion county:

Barren Measures.

Lower Productive Coal Measures.

Conglomerate Measures.

Mauch Chunk Red Shale.

Pocono Sandstone.

It will be seen that the strata of Clarion county occupy a very high position relative to those of the rest of the State. Only the lowermost strata of the Barren measures are found in the county in the Mahoning sandstone and shale covering of the Freeport upper coal, which cap the most of the isolated summits in the south. It is very probable that the Barren measures once extended all over the county, but they have been washed away by erosion almost to a nullity. Erosion, or the wearing away by water, ice, and aerial influences, has played a great part in the formation of the present surface of this region. When we speak of elevated veins of coal being “caught” in high hills, it is only a curt form of expressing the fact that this gigantic denudation was not sufficient to carry those strata away from the highest points. This agency is still at work every day around us; we see it in a minor scale in the washing away of banks and deepening of valleys. It is at work too on the surface of the country, but so slow that its influence is almost imperceptible. In prehistoric periods, however, it had none of its present subtlety, but with floods and glaciers washed away enormous slices in a comparatively short time.

The Lower Productive coal measures cover three-fourths of the surface of the county. Near their base the ferriferous limestone crops out in a comparatively attenuated vein, forming a labyrinth of over four hundred and fifty miles of exposure. In the north the erosion was relatively greater than in the south, and left bare the Pottsville Conglomerate series in extensive areas, though suffering the Lower coal measures to remain in some of the uplands and hills. It is accounted for by the greater thinness here of the coal measures, complemented by a rise, in a northeastern direction, of the conglomerate rocks. The deep beds of the Clarion and Redbank expose strips of Mauch Chunk red shale five feet in thickness, and a few feet above water level; the former at Cooksburg, the latter at Patton Station. So far as discovered this rock underlies only about the eastern half of the county, being displaced elsewhere by a greenish rock, found in drilling oil wells.

Underneath the Mauch Chunk shale there are vestiges of Pocono sandstone, but of difficult identification.

Drift — There is some glacial drift in the county along the river beds, but of small interest.

Soil — Soil consists of disintegrated particles of surface rock, mixed with decayed vegetable matter. The southern half of the county, with its large areas of limestone outcrop and loose shales and sandstone, of the coal measures, affords a much better natural soil than the majority of the northern townships, where the cold, sandy soil of the Conglomerate series predominates. Happily, however, this soil is capable of much improvement, so that a liberal use of limestone and manures has brought up farms in Farmington, Highland, and Elk townships to a pitch of fertility which rivals some of their better blessed southern neighbors.

Lower Productive Coal Measures — This group, lying between the Barren and Conglomerate, covers all the southern county, except small belts along the streams, and about one-half of the northern. It is this important bed which gives to our county its permanent mineral and agricultural wealth, and it is therefore worthy of our especial study. It has an average thickness of 335feet, and is divided into four minor groups, as appended, in their vertical order:

Freeport Group.

Kittanning Group.

Clarion Group.

Brookville Group.

In the Freeport group,. which is 135 feet in thickness, are found the Freeport upper and lower veins of coal. The following is an analysis of this group, with average thickness of each layer given:

All of these members are never found together.

The Freeport Upper Coal is found only in the summits of Madison, Toby, Perry, Porter, and Redbank townships, having been eroded from the remaining country where it was once general. It is capped always, either by Mahoning sandstone or an intervening shale, underlaid by fire-clay, and has an average thickness of three and one-half feet, with extremes of two and five. It contains over eighty-nine per cent. of fuel matter and one-half per cent, of sulphur. It is therefore good coal, but is too limited in area to be important. The limestone contained in this bed is a rare article. The iron ore stored between this limestone and the underlying sandstone occurs both as ball and plate ore; in the former shape permeating several feet of fire-clay, and in the latter having a thickness of from one-third foot to three feet.

The Freeport Upper Sandstone, a hard rock, lies between strata of sha1e and measures from twenty to thirty feet in thickness, but it is often entirely-displaced by shale.

Freeport Lower Coal.— This bed is found in the same townships as its higher neighbor, but in Madison, Toby, and Perry it is extremely thin and occupies only the highest hills. In Redbank and Porter, though limited in extent, it is largely worked, especially by the Fairmount and Northwestern Coal and iron Companies. Here it is a splendid vein, in thickness from six to seven feet, with no slaty laminae and very little sulphur. It is found in largest quantities on the Fairmount and St. Charles Furnace properties. An average specimen contained the following:

The limestone accompanying this coal is very variable, and often wanting, It occurs in layers, or “flags,” easily parted, and with rough surfaces.

The Freeport Lower Sandstone is a massive rock averaging seventy feet in thickness. It juts out magnificently along the Allegheny at Brady’s Bend, and tops most of the isolated hills in Piney, Monroe, and Limestone townships.

The Kittainning Group.—This important group covers the largest area, and has a thickness of from 110 to 130 feet. Its various measures are shown in their usual order, and with their average thickness, as follows:

The Kittanning Upper Coal is present in large areas in the southernmost townships, but owing to its comparative thinness and inferiority it is neglected. In the vicinity of New Bethlehem and Fairmount it is a good hard coal, from two to three feet thick. It is separated by a strip of impure fire-clay from the Johnstown Cement Limestone, which is here of ferruginous quality, of brownish color, and breaks up in irregular masses. This is a rather obscure vein, one of its rare exposures being upon Middle Run, one-fourth mile above the Fairmount Coal Company’s opening. So much iron does the bed contain in this vicinity that it may properly be termed an iron ore.

The Kittanning Middle Coal lies about forty feet above the lower vein and forty-five below the upper. It has about the same value as a profitable bed as the upper, and is said to yield an inferior coke.

Kittanning Lower Coal.— Thisseam stretches under the whole surface of the county, excepting Farmington, Paint, and Elk townships, and is the most extensively mined coal in the county. It is practically inexhaustible, large beds of it lying yet untouched by the pick. While not equaling the Freeport Lower in excellence and freedom from sulphur, its general availability renders it of far more economic value. At Redbank Furnace it lies forty feet above the ferriferous limestone, at Fairmount thirty-five, at Sligo from fifteen to twenty feet above, in Beaver township twenty, and in Knox and Highland it is only ten or fifteen feet above that stratum. The intervening space is occupied by a thick bed of fire-clay and sandy shale.

The Kittanning Lower coal decreases in thickness going north. At Fairmount, where it lies thirty feet above water level, it measures five feet in thickness, at Catfish four and one-half, at the mines of the Sligo Branch Coal Company near Rimersburg three and one-half feet, while in the northern townships it rarely exceeds two and one-half feet. By far the greater part of country banks are opened into this coal. In appearance it is a deep black, lustrous, with very little slate and a thin veneer of iron pyrites. It makes a superior steam fuel. An analysis gives the following proportion of components:

In Porter and Redbank townships there are outcroppings of a seam lying about thirty feet below the Kittanning Lower, and ten above the limestone. It has been called the Extra Kittanning Lower, and is of the same quality as the regular vein, but somewhat thinner. From all appearances it is a distinct bed, and not a splitting off of the stratum above.

The Clarion Group, so-called because it has its outcroppings at the horizon of the county-seat after a gradual rise from the south, is met in geologic order below the Kittanning, and has a thickness of about eighty feet.

It furnishes the greater portion of the fuel to the townships bordering the river on the north, where it lies near the surface and is easy of access. It contains the ferriferous limestone, the largest ore deposit, and the Clarion and Brookville coals. In the north the Clarion is the uppermost vein.

This group is an exceedingly variable one, partly by reason of a split in the Clarion bed, extending northward from a line through southern Monroe township, and partly from an irregular rise in the Homewood sandstone. The column below represents the usual structure of the formation south of the split:

This formation is modified by the displacement of the Brookville coal by the Homewood sandstone. The same may be said of the group north of the split. Its average arrangement is the following:

Iron Ore and Limestone  — That comparatively thin strip of mineral, lying all but immediately above the Clarion Upper coal, has played a capital part in the commercial and agricultural development of Clarion county. The ore, which is carbonate of iron, limestone, or buhrstone ore, rests almost invariably directly upon the limestone; the exception is when a thin strip of shale intervenes. Generally there is a distinct line between the limestone and iron, but at times the one merges into the other by a gradual shading. In favored localities, as on the Fox farm near Sligo, the bed is three, four, or more feet in thickness, but it has an average size of ten inches. The ore proper is in the plate form, but the superincumbent shale generally holds considerable ball or kidney ore. In external form it is bluish gray, rarely reddish in color; cellular, containing calc-spar and varying in structure from coarse to fine grained. By exposure and wetting this ore in some localities has become oxidized into hematite. Clarion county ore makes an excellent iron for all ordinary purposes, and some of its higher grades of hematite are well adapted for Bessemer steel.

The following is an analysis of a specimen of carbonate ore obtained from Hindman’s limestone quarry in Clarion township:

The following is from a test of hematite ore from Dale’s old bank near Shippenville:

The following is an analysis of iron ore from the St. Charles Furnace lands, Porter township, made by Dr. Genth, of the University of Pennsylvania, in 1881:

“It is a fine quality of limonite, capable of producing excellent iron, and well adapted for making Bessemer steel.”

Bog Ore — Deposits of this ore, which is also known as “limonite,” red oxide of iron, exist in Farmington township along the river, a mile below Alsbach’s Run, and at several other places in that vicinity. The area of the beds is unknown, as they have never been mined. Bog ore occurs in red lumps of a clay-like consistency. These beds have at present no economic value.

Limestone — The ferriferous (iron-bearing) limerock is Clarion county’s chief reliance as a decomposer, and its lime par excellence. Its average thickness is eight feet; in color it ranges from a light blue, through gray, to almost black. When it is found in any thickness it is often divisible into flags two or three inches thick, with undulating, rough surfaces. It contains fossils, though they are rarely found entire in the bed, owing to breakage in fracturing the stone. Beautiful vegetable fossils are sometimes found on the surfaces when exposed.

Clarion county limestone contains

Clarion Upper Coal — The upper bench of the Clarion is a fuel of good quality, but its thinness—about fifteen inches— makes it unprofitable. It lies a few feet beneath the ferriferous limestone.

Clarion Lower Coal is slightly thicker, as a rule, than the Upper, and a more valuable coal. It has a varying base; sometimes the Homewood sandstone abnormally elevated, often shale, and again the

Clarion Sandstone — This is a massive rock from fifteen to thirty-five feet thick, and roofs the Brookville coal. It is frequently exposed along the roadsides in clarion, Millcreek, and Highland townships. It can be distinguished from the Homewood or Tionesta sandrock by its position, its greater softness, friability, and pink color.

The Brookville Coal, the lowest of the series, consists of one stratum. It is a poor, sulphurous, and comparatively unused bed. It is found at its best in the eastern and northeastern townships bordering on Jefferson county, in which county it has its best development. It is sometimes entirely displaced by the Homewood sandstone, “which,” says Geologist Chance, “elevated by anticlinal rolls, or irregularities of original deposition, lies higher than the level of the ancient marsh in which the bituminous matter of this coal bed accumulated.”

Résumé — An inspection of the coal formations given above will show every bed roofed by shale, occasionally mixed with sandstone, except the Brookville coal, where the shale is entirely displaced by sandstone. Each vein, too, is underlaid by a vein of pure fire-clay, except the Kittanning Upper coal, where some shale is intermixed, and the Clarion Upper, whose substratum is a slaty shale. As a rule every, coal has its limestone and sandstone, varied by shale. The maximum thickness— nine feet— is found in the Freeport Lower coal, in Porter township; the minimum— one foot— in the Clarion Upper coal at Edenburg.

We may readily perceive that, with eight workable coal beds underlying, in due position, almost its entire surface, and without taking natural gas into consideration, Clarion county need never go begging for fuel.

Its agricultural demands are fully supplied by the limestone underlying two-thirds of the county, and its hillsides contain iron ore of good quality— enough to supply a future industry with thrice the demand, on its mineral resources, of the ante-bellum furnaces. The fire-clay, inseparable from the coal, supplies an abundance of plastic material for potteries and brick-kilns.

The virtual inexhaustibility of these products gives them a permanence of value superior to lumber and petroleum. In the case of oil, repeated ventures have failed to discover new territory; and as for timber, the growth of centuries is disappearing, never to be renewed in its pristine luxuriance.

For the future, then, its agriculture and its embosorned mineral wealth must be Clarion county’s sources of income. Greater development only and home manufacture are needed to supplement our county’s wonderful riches of nature.

Conglomerate Series — The Conglomerate series, No. XII in the table, as represented by the Pottsville division in this county, is characterized by alternate layers of very variable shale and sandstone, generally of a gritty, and at certain depths, pebbly formation. The total thickness of the group is rarely obtainable by actual exposure, and its determination by oil drillings is vague and precarious. As near as can be ascertained it extends under the Productive measures for 270 feet, the mean of variations. The strata underlying the Homewood sandstone differ widely in thickness, but their combined measure is almost uniform. The following shows the formation of the Conglomerate with mean thicknesses:

The Homewood or Tionesta sandstone, a coarse but hard rock, is found in precipitous ravines and valleys. It has its best development in Madison township, where, along Pike and Wildcat Runs, it forms crags sometimes forty feet thick. In the slaty measures subjacent to this rock there are thin, impure beds of ore and coal, corresponding in horizon to the Mercer beds. This coal seam has been worked at Catfish Run, in Paint township, and North Pine.grove, in Farmington township, but with indifferent results.

It will be noticed that the massive basal rock of this series forms nearly half of the whole. This is the rock that makes the precipitous sides of the Clarion River so rugged; sometimes jutting out in bold, almost perpendicular escarpments, but oftener broken up into bowlders. Colossal specimens of rocks detached from this stratum are found near water level at the mouth of Toby Creek, and a little to the east, on the hillside in the “Indian Cave” rock..

We have already sufficiently alluded to the Mauch Chunk Red Shale, and the Pocono Sandstone; they are comparatively unimportant.

Other Minerals.— Althougha vague tradition obtains of lead having been discovered within the county’s limits by the Indians, the negative results of search have established its falsity. It is safe to say that there exists no lead in Clarion county outside of the isolated particles of galena, which are occasionally found in the coal strata, whither they found their way in some unaccountable manner.

Alum-shale or alumite is found near the surface in considerable quantities at Alum Rock and vicinity. Whether enough exists to make the bed of commercial value remains to be seen.

Petroleum.— The eccentricities of the petroleum deposits of northwestern Pennsylvania have so far baffled research. When science leaves the tangible in the rocks of Mother Earth and would investigate the volatile and oily products found in them, it seems to stray into a realm as capricious and slippery as the substances themselves. All that can be done is to detail the conditions and incidents of the finding of oil, and give the most plausible theories as to the lay of the oil-bearing rock.

Petroleum is found in the Clarion district at an average depth of 1,100 feet, which would place it in the horizon of the Red Catskill formation. When the drill is started on a hill top, unless on the crest of an anticlinal, greater depth is needed; and, in a valley, less. The following table gives the usual order and thickness of the oil sand group of Clarion county, which is geologically known as the “Venango group”:

The first sand is found at a depth of from 700 to 800 feet and is distinguished by its gas; the second is a very indefinite article and is scattered between the first and third. Here, too, with a thickness of almost forty feet, is found the “Red Rock,” the distinguishing mark of the Venango group. Its position and attributes make its identity with the Pocono red sandstone probable. The third and productive sand, which, as all the others, is not a real sand, but a sand rock, is a yellow, porous rock, with little cement, and with its particles as they come from the pump ranging in size from a pinhead to a small pebble. These cells, or pores, contain the precious fluid.

The oil rock in Clarion county has, with the other strata, a noticeable dip a little west of south, but its constancy is affected by local variations and anticlinals. Its total descent from Shippenville to Parker exceeds 300 feet.

Range of Development — The Clarion county oil fields were developed on lines ranging from thirty to fifty degrees east of north. The former marks the first developed, Parker-St. Petersburgh belt, and is a continuation of the Millerstown belt in Butler county. Then a bend occurs, and from St. Petersburgh to Shippenville the general trend is on forty-five degree lines. In the Cogley district, too, the latter line obtained.

Theory of Deposit — The excessive variability of the oil rock largely accounts for the uncertain and capricious nature of development. With a porous rock the chances for oil are excellent, but this quality is by no means constant. Sometimes, unexpectedly in the midst of good territory, the sand changes to a hard, close cemented formation and a grayish color, shutting out the oil entirely, and puzzling the producer. Where the rock is coarsely cellular, and oil is found in most paying quantities, the fluid is of a dirty greenish color, almost opaque, and contains considerable bitumen. Where, however, as in the Armstrong Run territory, the rock is of a firmer consistency and a clean white color, the petroleum permeates it with difficulty and in small quantities; the filtration it suffers produces a clear yellow fluid called “amber oil.” So much for incidentals. When, however, we would lay down a rule of deposit, and limit discovery to certain continuous lines, the constant variations, the streaks, “wet” and “dry,” the pools, the abrupt limits of production, meet and baffle us at every turn. Among the latest and most plausible conjectures is the belt-line theory, and it seems especially well adapted to the facts of the Clarion production. This is that the oil lies in the rock in a belt, or ribbon, stretching across the country in a northeast-southwest direction. Its comparative narrowness is indicated by its name, as ,also the parallelity of its sides or slight divergence therefrom. Towards Shippenville, however, which marks the extremity of continuous development, the belt seems to gradually narrow down by a tapering in the rock, till a little beyond that village, a point is reached where the line of production is but a quarter of a mile in width and then disappears altogether, to reappear in a narrow, hardly-paying streak at Hahn’s Mill. Along the borders of a belt the open, prolific sand is invaded by patches of barren, causing production there to be very dubious. Beside the main belt, but with no connecting branch, generally, lie secondary side belts comparatively small in scope. The Cogley field illustrates this. Such fields, however, form an argument for the advocates of the pool theory, which comprehends only the existence of oil in arbitrary deposits of irregular outline, and completely isolated from each other.

A lower belt traversing the county from East Brady to Cooksburg and supplementing the theory of a continuous oil area from Washington county to Kane, exists only on paper. Repeated failures have discouraged drilling along this line, the only venture that proved productive being the old Blyson well, which yielded an oil heavy enough for lubricating purposes. The underlying “Fourth,” or “Bradford,” sand is yet an almost unexplored region. Perhaps it is destined to duplicate the rich territory which Clarion county once possessed.

It suffices here merely to mention the connection which some theorists maintain to exist between oil belts and anticlinals; but this is merely a tentative conjecture, lacking any confirmation. So much for the extension of petroleum deposits; their origin is as yet a matter for mere scientific conjectures. Whether petroleum is an excretion from organic matter embedded ages ago in the rocks; whether it sprang immediately from carboniferous beds, was condensed from natural gas, or had its origin from some unimagined alembic; these are all yet unanswered queries, and the likelihood is that they will remain so; that the Providence that placed the oil where it is, has here set his bounds to the acquisitions of the secular mind in this mysterious department of physical research.

Natural Gas — The best grounded and most popular deposit theory of this new and remarkable fuel is the anticlinal, viz., that the rocks, finding their highest elevation in the, anticlinal ridges, the gas, whose gravity is less than water and oil, will seek the highest possible level and accumulate in greatest quantities in the anticlinals. This to a certain extent is very reasonable, but there are several conditions which make it invalid as a rule. We must bear in mind that while the surface of the country is (geologically speaking) intersected by synclinal valleys running ma northeast and southwest direction, there is, independent of these, a monoclinal or progressive dip of the strata to the southwest. Hence gas, in seeking the highest available level, should accumulate in the northeast, at the expense of the southwestern extremity or bottom of the dip. The same cause places a larger deposit of gas where the rock resumes the horizontal, after the anticlinals have disappeared in the north, than in well-marked anticlinals which lie to the south and on a lower plane. This rock of course must be an oil rock, whether productive or not. Again, a whole belt of oil or gas rock may lie in a broad synclinal basin and be almost unaffected by the tilt at either side. That the Lawsonham synclinal is of this nature, is a plausible explanation of the fact that the Mechanicsville gas deposits are not found on an anticlinal. The New Bethlehem well is low down on the slope of the Anthony’s Bend anticlinal.

Inexhaustibility — Reason and experience both warn us of the transitory nature of this fuel. There is no known inexhaustible reservoir of natural-gas. As Geologist Carll says: “Inexhaustible wells must draw from inexhaustible sources. Gas in Pennsylvania is only found in sand-beds of medium thickness and restricted geographical limits. Such beds in themselves cannot be inexhaustible. Their productive duration depends entirely upon the drafts made upon them— a simple problem: if one well can exhaust one of the beds in 100 years, how long will it take 100 wells to do it? To make such pools permanent they must be constantly replenished from an unlimited source. This source it is claimed is some deep-seated laboratory of nature, capable of responding to all the demands that can be made upon it.” But the existence of this deep-seated laboratory is yet to be demonstrated.

Fuel Value — The fuel value of 1,000 feet of natural gas is equal to that of about 65 pounds of Clarion county coal. Therefore, when coal is worth $1.25 net per ton, the value of gas is within a fraction of 4 cents per thousand feet.

 * For data for this chapter the writer is mainly indebted to “Report of Progress, Second State Geological Survey,” Vol. VV, by H. Martyn Chance.

 SOURCE:  Page(s) 42-56, History of Clarion County, A.J. Davis, A.J.; Syracuse, N.Y.: D. Mason & Co. 1887 

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