UC-NRLF 261 Isogeotkerm Hypothesis ^"MINERAL OCCURRENCE and ORIGIN Ike ORIGIN of PETROLEUM Coal, and Otter Carbonaceous Products, By Wm. Plotts GIFT OF ^ Isogeotnerm Hypothesis o/"Mineral Occurrence and Origin Origin V Petroleum Coal, and Other Carbonaceous Products. Snowing how these products occur in orderly, definite, limited horizons, independently of the plane of stratification. By WM. PLOTTS i#ier, California. Whittier, Calif ornia. April, 1911. Price, $1.00. WILL A. SMITH'S PRINT SHOP Whiter. California 191 1 ISOGEOTHERM HYPOTHESIS OCCURRENCE*/ COAL, PETROLEUM, &c ^Petroleum and coal occur in strata of various ag'es, the general series of which may be of the greatest variety of texture and hardness, and the general appearance of which may vary greatly in different fields, but in every region where they occur there is a something in common that is more or less discernahle to the observer, but which is very difficult to describe. I am not now referring to the oil stains or coal blossom that are generally easily distinguishable where erosion has cut into or through the oil or coal horizons, but to the series of strata in general, extending thousands of feet above and below those products. d^M an y observers, in trying to define this simi- larity, call it the age of the strata, it apparently being much younger and more crumbly than strata in the same series many thousands of feet under it, but this is not the true solution, as dif- ferent oil and coal bearing strata vary greatly in age, as determined by the fossils occurring m them; those of Pennsylvania, for instance, being probably several times as old as those of Califor- nia. The true solution is: each horizon of like products has been subjected to a like approxi- ISOGEOTHERM HYPOTHESIS mate pressure from the mass of material above it, and to an exactly lite maximum of heat at the time of its greatest subsidence; and that this heat was the point of distillation of these products (probably several hundred degrees), seems quite plain, and that the source of this heat was the presence of enough material above the carbona- ceous horizons to create it through the orderly increase of heat downward in the earth s crust, must become apparent as soon as the facts in con- nection are generally known. ^ The classification of strata, according to the amount of pressure and heat they were subjected to, is of the greatest importance from a mineral standpoint, when we consider that most of the earth's present land surface has plainly had miles of material eroded from above it. This feature must not be lost sight of if we expect to form rational theories of the present condition of any part of this grand old earth s sub-surface. ^L The original superficial deposits above the petroleum must have been so vast, that where only half of them remain, the petroleum must be hopelessly beyond our reach. That this is so, is proven in many ways, the most simple of which ISOGEOTHERM -IYPOT IESIS is the very slow augmentation of, or increase of firmness m the strata as you trace them strata- graphically downward. It also seems plain that thousands of feet of the upper portion of the original deposits could have been little else than loose, incoherent masses, owing to the lack of sufficient pressure and heat to knit them into substantial strata, sufficiently firm to resist the wave erosion, as they emerged above the surface of the ocean. 41, In the following pages I intend to show that petroleum, in the continuance of its aggregate occurrence, forms a definite, limited horizon independently of the plane of stratification; and I hope that the reader will not lose sight of the grand and enormous scale on which the series of deposits were originally laid down, the slow rate of increase of heat in nearly all strata, and not to expect to observe a "made to order , or con- tinuously regular horizon, because nature has been the constructor, and she does not work along geometrical lines; and I hope to convince you that it occurs in a former isogeotherm (plane of equal heat in the earth) , and that coal, and many other more or less closely related products, occur in like ISOGEOTHERM HYPOTHESIS manner, also limestones of like type, and ttat many, perhaps most of our mineral, and non-min- eral eartt products nave a closer relationship to each otter, ttan tas teen supposed. Most, if not all, of tte metallic minerals seem to occur in tori- zons independently of tte stratification, that represent former isogeotterms; tut ttey do not necessarily occur in tteir zones of former fusion or volatilization; for instance, certain cartonate iron ores of a certain type occur numerously in, and seem to te confined to, tte coal tonzons. Ttey may te said to te of purely ctemical origin, tut it seems ttat ttey required a certain degree of teat in order to enatle tteir constituents to comtine. ^L In pointing out tte origin of petroleum, and otter carbonaceous products, I am not going to tring to my aid any tteoretical conditions of an exceptional or miraculous nature, or conditions ttat migtt result from some catastropte; tut am merely pointing out wtat must occur under nor- mal conditions, suet' as we know of today. CL To give a tetter understanding of tte sutject, I will now give in tnef a summary of my con- ception of tow petroleum and kindred products ISOGEOTHERM HYPOTHESIS were concentrated in strata, and the probable source of the carbonaceous matter from which they were formed. ^ All authorities of any note now concede that most parts of the dry earth show evidences of former subsidence and emergence during incon- ceivably long ages of time, and may, and some certainly have, repeated the process over and over again, and that some of these subsidences, and subsequent elevations, have amounted to several miles vertically. Of course this may seem fan- tastic to many, but I am only appealing to those who have given the matter some thought and in- quiry. The best evidence that we can get is, that this buckling of the earth's strata is going on now as actively as ever, and has been going on for a time that is practically infinite, d^ AiVe see different kinds of debris and sedi- ment carried continually into oceans, building up the strata on the bottom. In this sediment is a proportion of vegetable matter, composed mainly of finely ground up leaves, etc. The remains of the lowest animal life might also in some cases, be sufficiently preserved to contribute, but the vegetable remains would seem to be ample. ISOGEOTHERM HYPOTHESIS CL Of course, the percentage of suck remains in any strata might be small, but the aggregate in miles vertical of strata would be enormous, and from such deposits perhaps miles thick, we might expect to come the principal part of the carbon- aceous matter that forms our petroleum, coal, our massive limestones, and allied minerals. ^L Now, we know that downward in the earth s crust, the heat increases. To the thoughtless this increase of heat might seem too slow to be applic- able to our purposes, but we recollect that nature s operations are conducted on a grand and tremen- dous scale. 4I,Of course, where a succession of regular strata is being built on an ocean floor, there is a gradual subsidence of the region, which might continue many million years, and after the subsiding strata became sufficiently hot, on account of the con- stantly added material above it, the heat would drive the distilled matter from the leaves, wood, etc., upward. Or rather, the resulting volatil- ized matter, instead of subsiding with the strata, would maintain its relative distance from the surface, or at least from the bottom of the ocean, as the constantly reinforced mass subsided, "skim- eight ISOGEOTHERM HYPOTHESIS mecT of its carbonaceous matter, which accumu- lated in quantity according to the amount of subsidence, and the richness in said matter. d,To those who nave had experience in confin- ing gases under great pressures, there is no dif- ficulty in conceiving the possibility of compounds of carbon penetrating and permeating any strata when at several hundred degrees temperature and tons pressure per square inch, and at the time of maximum subsidence of the region, which would only occur after ages, the varying car- bon compounds would be left blended with the strata, confined to a definite, vertically limited, horizon, which would occur independently of the plane of stratification, and during the long ages of emergence and erosion, they would become further concentrated, and more or less firmly fixed by chemical affinity in the different forms in which they are now found. HOW PETROLEUM OCCURS in STRATA C[, Petroleum occurs in any kind of porous strata that happened to be in its horizon of general oc- currence. This horizon is always limited verti- cally, and in its continuance thruout large areas ISOGEOTHERM HYPOTHESIS always occurs independently of the plane of stratification. Of course I do not mean that the horizon is evenly or continuously productive in petroleum; hut that the successive or overlapping deposits all occur in this limited horizon; often with very extensive unproductive gaps between the productive portions. The common practice of speaking of successive horizons, one or more ahove others, is incorrect and misleading, as there cannot strictly he more than one oil horizon in the same locality. d, ^Ve almost mvariahly find oil in such envi- ronments as show that it could not possihly have arrived there in its present liquid condition. Any oil prospector that has investigated much can testify to this. It is common to find pitted limestones of the hardest kind with the pits full of oil, on the surface, where it has weathered for ages, where the oil horizon has heen eroded away. CL It 1S common to find oil in sandstone, and pehhle rock sometimes of adamantine hardness, altho much of the oil in the newer formations, like that of California, Texas, and Mexico, occurs in sandstone so soft, that the expanding gas that ISOGEOTHERM HYPOTHESIS occurs in connection with all oil, pulverizes the sand strata, so that sometimes large quantities issue with the oil from the wells, hut most gen- erally the stata is too firm to cave. d. Those sandy strata were, of course, laid down under water, and the fact that they are barren of water generally, proves that hefore the oil took possession, they had of course, sub- sided to a great depth, too great for water to occur as such, the heat or other chem- ical action having disassociated the component elements. Cl^^V^ater of varying degrees of impurity some- times occur in the oil strata under the oil, hut it seems plain that where such is the case the presence of the water is the result of erosion, or faulting, long after the advent of the oil, and perhaps after the surface had been cut to within comparative nearness to the oil. d. "Where water has obtained access to deposits of oil the latter has generally slowly percolated to the surface, or sub-surface, in sufficient quan- tity to betray the petrolific character of the locality and region. If the oil is of dense kind, containing much asphalt or other basic material, eleven ISOGEOTHERM HYPOTHESIS the residuum from suck seepages sometimes occurs in large quantities. 4L Of course the oil and gas, and other fluid substances are under pressure in accordance with their depth, the discussion as to the cause of the pressure is without point. It would be a mira- cle if they were not under pressure until tke pressure is removed by artificial means. 4L The actual pressure in a virgin oil "sand" or deposit is always in accordance with its depth below the surface, and is probably always below the pressure exerted by a column of water from the surface to the deposit, because as the region emerges and the surface is worn away, the de- posit becomes cooler, causing the gases to condense and the pressure to decrease accordingly. Of course it often happens that the gas pressure in a well-hole will overcome the hole-full of water, or even thin mud, causing a "blow out", but this is owing to gas in considerable volume having free access to the hole, when the ascending gas, by lightening the column of water, would slowly overcome it. 41, If there are numerous oil showings on the surface where the strata is horizontal, or only twelve ISOGEOTHERM HYPOTHESIS moderately tilted, the valuable oil deposits, if any, are usually of only moderate depth and it is use- less to drill to a great depth; and in similar strata if oil is found at a great depth there is never any showing on the surface. ^L Many times operators have drilled explora- tion wells a couple of thousand feet below the productive zone in search of another profitable deposit, but such attempts have always been fail- ures. However, in localities of exceptional disturbance the oil horizon is likely to be more erratic and irregular than elsewhere. ^L \Ve sometimes read geological reports of oil and gas, where the writers suggested that those products had moved freely through the strata and had arrived from afar along with the "cir- culating waters." Such writers observation must be very superficial and their logic faulty, for those products are firmly incorporated with the strata of which they are practically a part; were it not so they would have been lost ages ago. The continuance of porosity of an oil stratum is usually quite limited or the grain is very fine. C, It sometimes happens that a well is opened where the oil is under full pressure, in old ter- thirtecn ISOGEOTHERM HYPOTHESIS ritory where adjacent wells had teen exhausted and abandoned for many years, and many other circumstances show us how thoroly the oil is con- fined to the strata where it had to remain ever since it was forced there in a volatilized form. C[, There is a wide-spread notion that oil is a concomitant of certain strata and that if it is found at all it must occur in those strata, and that it is most likely to occur indefinitely in con- tinuation of the plane of stratification from where it is known to occur. 4L This helief has been a very costly error, for the aggregated deposits of oil in their continuance, despite the irregularity or their occurrence, form a definite horizon which is limited in vertical scope and which is rarely in exact conformity with the bedding over any considerable scope of country, and whenever an oil-containing stratum extends outside of the orderly zone of oil occur- rence (unless the porosity should be continuous beyond any known example), it is bound to be barren of oil and thereafter remain so, unless it should re-enter the oil horizon, which would be improbable. 4^ \Vhere the oil occurs extensively and per- fourteen ISOGEOTHERM HYPOTHESIS sistently in certain strata to which it has teen narrowly confined over a considerable area< geol- ogists have repeatedly and foolishly predicted that it would not occur in adjoining regions or localities because they were stratigraphically much higher and much younger; and when oil was found there in violation of their warning, the geologists would explain that the original lower stratum was the place of origin of the oil but that it had "" migrated upward", and urged deeper drilling in order to tap the basic sands. It is perhaps needless to add that where such advice was acted on it was unproductive of any good results. Contentions of this kind never had any basis of fact. C. If we could drill a well 30,000 feet deep do you suppose that we might find some oil at, say 1000 feet, and then go 5000 feet further and find another batch, and perhaps a few thousand feet below that find a bed of coal, etc.? Not at all. If oil was found at all the bulk of it would be found to occur in a vertical scope of a few hundred feet with possibly traces extending as much as 2000 feet above, and a less distance below, and below that no more would be found unless you fifteen ISOGEOTHERM HYPOTHESIS could continue the hole to the Hellespont or China. If coal occurred it would be found above tne oil, as it occurs everywhere that those two products are found in the same locality. CL Critics who fail to see an orderly, definite horizon that occurs independently of the bedding in the apparently irregular, hap-hazard group- ing of the different oil "fields when viewing the matter in this regard, seem to be expecting a "made to order" horizon where the fields would occur without wide gaps and in a perfect plane; but nature does not work along geomet- rical lines or in any manner that could be des- cribed as regular, so I have described the hori- zons of mineral occurrence as " "orderly in the sense of their occurrence vertically, because I well know how very irregularly those products occur in their zones or horizons. d^ Each group of like products occurs in a com- mon horizon, but any chemist knows what a great difference there is in composition of the dif- ferent kinds of mineral oils, or of the different kinds of coal. Different kinds of oil being there- fore of unlike kind might be expected to range in different positions in the grand horizon of pet- ISOGEOTHERM HYPOTHESIS roleum occurrence, and it is common to find sev- eral beds of oil-containing strata overlaying each other, and occupying a vertical scope of possibly a thousand feet, altho it is more commonly con- fined to three or four hundred feet. In Cali- fornia, the several oil deposits may, including traces, extend vertically as muck as three thous- and feet, but such is rare. Much observation of the phenomena of petroleum occurrence has led me to think that cases of migration of petroleum out of its original zone of deposition are rare, except where erosion has permitted water to obtain access to oil, when the latter would slowly escape to the surface in the form of a seepage, which generally would require thousands of years to exhaust a deposit. 4L Petroleum found in different fields is never identical in composition. It ranges all the way from the tarry product of Trinidad, Mexico, and California, to the light product of the Ap- palachian region, Colombia, Java, etc., which is nearly as thin and clear as water. In some fields like ^Vhittier, California, although the oils may conform to a certain type, there are hardly two wells that produce identical oil. Not only is the ISOGEOTHERM HYPOTHESIS gravity varied, but the character of the oil other- wise is different. In the latter field the oil hor- izon cuts diagonally across the trend of the steeply upturned strata; and there are perhaps one hun- dred different producing stratums; and as many of the wells obtain oil from several strata, and as each stratum contains different oil from its neighbor, the resultant blend is rarely exactly alike in any two wells. There is no such a thing as drawing a definite line between asphaltic oils and oils of paraffine base, as practically all oils contain both asphalt and paraffine, in traces, at least. Even in products resembling either coal or petroleum, it is difficult to draw the line between the two, for coal and kindred products blend into those resembling petroleum. CL Petroleums of different character are often blended with shale of so fine a grain that the oil can hardly be detected except by smell. Such oils can only be obtained by distilling the shale, which is done profitably in some countries. The writer has seen such shales that looked, to his unpracticed eye, exactly like some cannel coals, which will also yield oils by distillation. Lime- stones in the horizons of petroleum, often smell eighteen ISOGEOTHERM HYPOTHESIS strongly of oil. In western Texas, and the lar- ger part of eastern New Mexico, over an immense region, notably at Las Vegas, the harder shale, when freshly Jug smells strongly of oil. " Stink- ing rock" is of this nature, as nearly all oil pros- pectors know. CL If petroleum occurs in strata of one age more than another, it is probably one of those things which might be considered as accidental; and ability to determine and classify strata by their age according to the fossils they contain is not of the slightest value to the prospector. Indeed geology has never had the slightest knowledge of any value to the oil man, notwithstanding many promotion oil companies loudly proclaim that their properties are recommended by some "ex- pert geologist" who gives a long dissertation of his "knowledge" to the suckers; and of his ignorance to the rest of us. There are many expert oil men who make a business of passing judgment on properties for others, and some of them prefer to be called geologists to which we can not object, but the odium that has been connect- ed with the term of late would seem to be enough to dissuade any from attaching it to their names. ISOGEOTHERM HYPOTHESIS d^ The character of the oil, also, does not seem to be affected by the age of the strata in which it is found; for, altho the great bulk of the high grade oils have been found in very ancient for- mations, and nearly all the large production of heavy oils is produced from formations of recent age, the reverse is true of the very light oils of Java, India, and Colombia, S. A.; and of the rather inferior black oil of western Ohio and eastern Indiana. CL The similarity in appearance of the strata that is so noticeable in all regions where petroleum and other carbonaceous products are found, could only be caused by the degree of heat and pressure to which those strata in which these products are found were sub] ected at the time of their maximum subsidence. However, petroleum and coal bear- ing strata of great age, which were presumably subjected to pressure of the superincumbent strata for long ages, are firmer than are those of recent age, as might be expected. For instance, the shales of Pennsylvania, among which petroleum and coal are found, are much harder than the shales of California where the same products occur, but the same general appearance and color- twenty ISOGEOTHERM HYPOTHESIS ing, and other indescribable conditions prevail in both regions, although one is vastly older than the other. ^L The definite, vertically limited oil-contain- ing horizons of California, although not continu- ously productive, occur sometimes in considerable non-conformity with the plane of stratification, and sometimes obliquely cross the demarkations, where one series of deposits rest unconformably upon another. The same is true in the Appa- lachian and middle west region, where the imme- diate surface for a thousand to two thousand feet, over the whole country, is an almost unbroken petroleum and coal horizon, although those prod- ucts occur in separate deposits, or groups of de- posits in that horizon, often widely separated from each other. That the successive deposits, do collectively, in their continuance, represent on a grand scale a definite limited horizon, which really occurs on lines of a former isogeotherm, must become apparent on sufficient consideration, altho why the deposits do not occur more con- tinuously in that horizon has never been satisfac- torily accounted for. twenty-one ISOGEOTHERM HYPOTHESIS HOW COAL OCCURS IN STRATA. CL, Coal also occurs in a horizon which in its continuation, is independent of the stratification. It commonly occurs in the same locality with petroleum, and is always above the petroleum, usually 1000 to 1500 feet. Sometimes it is as much as 2000 feet above, and in rare instances, it is but a few hundred feet above, and slight quantities of oil have been known to seep upward into coal mines that had recently been opened. ^L The petroleum and coal horizons always par- allel each other, regardless of the non-conformity of their horizons to the plane of stratification, showing that the relationship between them is intimate, as could not be otherwise; for in the various carbonaceous products resembling either petroleum or coal, it is difficult to draw the line, as there is a gradual blending of one into the other. C, If we consider the limited areas of coal regions, and the still more limited area of the known oil-containing territory of the world, we must admit that if these two products occurred together in six or eight different regions, it would seem more than a coincidence. But when we consider that nearly all the petroleum of the twenty-two ISOGEOTHERM HYPOTHESIS world occurs in close proximity to coal, we may justly consider the fact of their relationship to be firmly established, and I will say more about this phase of coal and oil occurrence. CL People past middle age who have been inter- ested in geological maps have noticed that the '"carboniferous" areas have enormously increased the last two or three decades, which time is re- markably coincident with the discovery and de- velopment of coal all over the world. This stretching of the carboniferous over what was formerly classed as permian, and devonian, re- minds me of the professional "oil smellers. Those good old uncles, 'who formerly used a forked peach branch to "trace" the oil belt, now commonly have a much more elaborate and en- tirely inexplicable machine to prognosticate with and supply a long felt want of unsophisticated land owners. The point is this: the "uncles display wonderful acumen in tracing the oil-con- taining belt or deposit, in so far as it has already been proven by the pioneer operator with his drilled wells; but there is no well attested case of their having been themselves successful as pioneers. twenty-three ISOGEOTHERM HYPOTHESIS 4L The extension of the carboniferous has evi- dently teen for the purpose of bolstering up the popular (and precarious) notion that there was once an age or period of extraordinary develop- ment of vegetation; which belief was in its turn necessary to bolster the popular theory that coal represented accumulated vegetation in situ, a theory which has no basis in fact, as I intend to show, but which has acquired a widespread acceptation owing to a mass of apparent evidence which has appealed strongly to the superficial investigator, and owing to the persistence and in- dustry with which this apparent evidence has been collected and advertised. d. The more our knowledge of this old earth accumulates the less need we have for promul- gating theories of special or exceptional condi- tions, and the writer who tells us of wonderful catastrophies in the dim past, no longer is honor- ed above those who can only see evidence of an orderly course of nature, similar to what we can ohserve in our own short time. CL Coal, like petroleum, occurs in strata of all ages except the very youngest where there has not been sufficient time for the enormous sub- t-wenty-four ISOGEOTHERM HYPOTHESIS sidences, and subsequent elevations, with the at- tending erosion which is necessary to bring those products within our reach. C[,It is popularly telieved that hard, or anthra- cite coal hecame differentiated from other coal hy having suhsided to a great depth after the carbon became fixed, and where the heat oper- ated on it. C,That the heat operated on it the same as on other coal, and no more, is what seems to be proven by anthracite that occurs above a pe- troleum horizon in the coast country of Colom- bia, near Barrenquilla, South America. The coal occurs sparsely at several places, apparently 600 or 800 feet above the oil horizon, which latter is well marked. The writer did not ob- serve any, or hear of any deposit that was worth working, but it is there just the same. The strata is recent, probably tertiary. C,The fact that sometimes coal is hard, at other times soft, or coking, or non-coking, or a worthless lignite, or merely a manifestation of coal, seems to make little difference in regard to its occur- rence in orderly horizons and its relationship to other minerals, and the deep secrets of na- twenty-five ISOGEOTHERM HYPOTHESIS ture s processes are beyond our ability to fathom at present, except where we get the key to them in the plainest manner. CL 1 here has been much microscopic investigation of coal, with a view of studying its origin, but it is safe to say that the results have been entire- ly unsatisfactory, as they had a tendency to show that each different stratum was formed of differ- ent matter. This is exactly what might be ex- pected, for coal is merely ordinary strata that has been changed, and which contains more or less clearly marked impressions of the coaser debris that the original sediments contained, the finer lines of the leaves or other debris being some- times brought out by the black particles of coal on a background of lighter colored shale, in a wonderful manner. d^The best examples of this seen by the writer (who has worked in coal mines,) occurred in the shale, with only fine particles of coal matter to produce the markings, and as other strata, even limestone, contain impressions of vegetation, ap- parently as frequently as coal, why are not those strata coal, if such evidences of original vegeta- tion prove the accumulated vegetation theory? twenty-six ISOGEOTHERM HYPOTHESIS n some ligmtic coals that might he designated as immature, where there may not have been sufficient time or other essential conditions to completely form the carbonaceous gases into "fixed carhon, pieces of carbonized wood have heen found, being of such a nature as to corres- pond with the rest of the coal seam. It is noted, however, that when wood remains are found ahove or helow the coal, they are almost mvar- lahly petrified, silica having taken the place of the original chemical constituents. ^Geologists have industriously gathered and placed on exhibition many exhibits which ap- parently evidence the correctness of the com- pressed vegetation theory, and a museum of min- eralogy is hardly considered complete without one of them. Almost every geologist of note has gone into print endorsing the idea, which they will hardly abandon, until the oil men find it universally profitable as well as instructive to search for oil in horizons of former isogeotherm. CJn the Royal Geological Museum on Germyn Street, London, there is an exceptionally com- plete series of exhibits, tending to show that coal is compressed vegetation, and if one-half of the twenty-seven ISOGEOTHERM HYPOTHESIS labor and ingenuity had teen bestowed upon stowing tbat coal is merely cbanged strata, in wbicb tbe cbemical constituents bad been re- placed by carbonaceous matter, and tbat tbe ag- gregate occurrence or coal in its continuance, in any region, represented a former isogeotberm, tbe tbeory would bave been well proven. d/Tbere is one exbibit in particular, in tbe Lon- don museum, wbicb is wortb mucb study. It is intended to sbow tbat an intrusion of gabbro bad cbanged tbe nature of tbe adjacent coal, but to a keen observer it only sbows tbat tbe intrusion bad occurred before tbe coal was tbere. Tbe coal, wbicb still adbered to tbe piece of gabbro, does not seem to bave been cbanged by subsequent beat, its exceptional appearance (it is an odd looking semi-antbracite and is probably cbanged gabbro) baving evidently created tbe im- pression tbat it bad been cbanged by beat. Had tbe exbibit consisted of a large portion of tbe coal bed, witb some of tbe intrusive rock at- tacbed, it would bave been of mucb more value. ^Tbe great bulk of coal strata was formerly a soft, massive sbale, or bard clay, of mucb uni- formity of texture, wbicb seems to bave been twenty-eight ISOGEOTHERM HYPOTHESIS best adapted to arrest and receive the carbon- aceous matter, out in exceptional cases apparent- ly any kind of strata turned into coal. Even coarse pebble, tbe waterworn roundness being well preserved, has formed coal. CL A popular geological writer, who of course was an adherent of the compressed vegetation theory, having such a case brought under his ob- ssrvation, says: in a period of elevation, the superincumbent strata must have been eroded away, and the coal bed cut into by a rivulet, which formed a bed of waterworn coal pebbles in the coal bed itself: after which the region subsided, and was covered by sediment as be- fore/ This is a sample of the immature reason- ing that has established a theory which is act- ually taught in our schools. First, the coal was formed, necessitating a covering of thousands of feet and perhaps millions of years to compact the bed of vegetation into good coal: then erosion, which is so slow, that where our present coal beds have been cut into by erosion, it requires a practised eye to determine that there ever was a coal bed there, and the "blossom" has to be traced by drifting, often for a hundred yards twenty-nine ISOGEOTHERM HYPOTHESIS from the surface, before any coal good enough for use can be obtained, the outcrop having been destroyed, or deteriorated, by access of air. It is well known that the best commercial coal deteriorates in value, by being stored in the open air, and for this reason arrangements are being made to store it under water. But entirely ob- livious of the perishability of coal, this ""author- ity had the coal actually worn into pebbles by slow erosion, and then covered up by the set- tlings of erosion, without affecting the quality. CL The popular hypothesis of coal origin as pro- mulgated by the geologists of the last few decades is quite definite, and I think that I will not be charged with unfairness when I state that it supposes each bed or vein of coal to repre- sent an accumulation of vegetation on the ground on which it grew: after which, the region sub- sided, and was covered with sediment which be- came the soil in which another accumulation of vegetation grew, when the region again emerged, etc. Those theorists neglected to make pro- vision for preserving a sufficiency of vegeta- tion from decay pending its submergence under the ocean, and when we consider the perishable thirty ISOGEOTHERM HYPOTHESIS nature of coal itself, to say nothing of vegeta- tion, the idea seems absurd. CL The immense amount of carbon contained in a large coal vein, and the small amount contained in a yearly growth of vegetation, must have rather queered the gentlemen, for they agreed that it took an enormously long time, which they reckoned into the hundreds of thousands of years, during which time the mass, which must often have been hundreds of feet in thickness, was in some inexplicable manner preserved from decay. C, Now, the accumulation of such an immense amount of carbon by growth is an utter impos- sibility, owing to the limitation of fertility of the soil. Any good farmer can tell you that without the application of matter containing cer- tain salts, the best soils would become unpro- ductive, if heavy crops were taken off continu- ously. Before the vegetation would suffici- ently decay for the salts to become again avail- able, the carbon matter would all have escaped into the atmosphere. Then again, the large number of subsidences and elevations that, in some caaes, would have to occur successively, thirty-one ISOGEOTHERM HYPOTHESIS during the building up of a very small amount of strata, is hardly consistent with our under- standing of such phenomena. CL The helief in the accumulated vegetation theory, seems to he based mainly on the fact that fossil impressions of vegetation are found to occur in coal, but they also occur intermittently in the whole series of deposits in which the coal occurs, as frequently as they do in the coal. In some coal, no fossil vegetation whatever can be detected, in other coal it is common. The same is true of the shales. Many geological writers have stated that coal measures (which term, if it means anything, means the coal containing hori- zon) were many thousands of feet in thickness, but we must consider their methods of deter- mining the thickness, which was by aggregating the thickness of all the strata in which coal oc- curred at any point. Had the result been deter- mined by drilling a deep well at any point that they might have selected in the coal regions, they undoubtedly would have found that the whole horizon or coal occurrence would have been con- fined to a f ew hundred, or at most, a thousand feet. CL But the feature of the geologists theory of thirty-two ISOGEOTHERM HYPOTHESIS coal orig'm, that is most opposed to reason, how- ever, is, the emergence of those thin sheets of clay strata between some of the minor coal seams, which strata are sometimes only a few inches in thickness, and extend over large areas, and which, before they had hundreds of feet of covering were nothing hut slimy pulp like occurs now on the bottom of the deep ocean, the only place where clayey shales are formed. The absolutely uniform texture of those shales would prohibit their formation in a lagoon, or in any other place whatever, except on the bottom of a very deep ocean, at a great distance from shore, and it is too much to suppose that in their emergence they would survive the wave erosion, of which I will speak further on. Some geologists think that coal- beds represent accumulations of driftwood, but this theory, also, presents insurmountable diffi- culties, as it -would require the postulation of conditions enormously different from any we know of. But it is not necessary to further dwell on the absurdities of the compressed vegetation theory, altho a book might be filled with them. d. Coal sometimes, especially in much disturbed mountain regions, occurs in immense masses, m thirty-three ISOGEOTHERM HYPOTHESIS very limited areas. The name, "horse halls applied to one series of them, will give the reader some idea of their form, which however is gener- ally irregular. In most of such occurrences of coal, it is plain that there is little or no con- formity of the coal, to the plane of stratification. Stratag'raphy of the west-end Whittier oil field looking east further S. E. the dip is not so great. Light lines represent the bedding; short heavy lines represent oil deposits, which, in their aggregate continuance, form the oil horizon, which represents a former isogeotherm. d^ But there is hardly a coal-bed, or vein any- where, that does not display in some portion of thirty-four ISOGEOTHERM HYPOTHESIS its extent, some unconformity to the bedding, and I wish to call the reader's attention particularly to this point. It must be apparent to the care- ful student that if this is true, it alone, must es- tablish the origin of coal in the manner herein set forth. If you enter a coal mine in the Pittsburg, Pa., district, and travel towards the south, you will notice by observing carefully, that the coal en- croaches gradually on the strata above, and cor- respondingly vacates the strata below, until in the course of half a mile or so, the whole vein Diagram, showing the prospector how the successive occurrences of petroleum and coal are likely to appear on both sides of the same anti-cline. will be in different strata from where you first observed it. In other coal fields, where this non-conformity to the stratification is much greater, and the separate veins or beds of much less extent, the field is a succession of veins oc- curring in a series of benches or steps, generally overlapping each other, each vein conforming thirty-fire ISOGEOTHERM HYPOTHESIS fairly well to the stratification, out the whole field throughout its continuance being sometimes as much as 20 degrees out of parallel with the stratification. It is in such cases as this that careless investigators have stated that the coal occured throughout a horizon of thousands of feet, when in reality the actual horizon of coal occurrence did not exceed a few hundred feet. CL Now, the only logical deduction that can he made in regard to this occurrence of coal (and other mineral) in an orderly limited horizon, independ- ently of the stratification, is, that it was formed subsequently to the formation of the strata with which it is blended, and at the time of maximum subsidence of the region, the coal field as a whole, was spread out approximately horizontal, parallel with the surface, but the stratification was not. (Strata of any considerable age is never exactly horizontal.) Chemical investigation or a series of strata m which coal occurs, shows us that there is a great excess of free silicates in the strata adjoin- ing the coal. The same is often true of iron ore. The shiny, greasy appearance of the cleav- age is a manifestation of this change in chemical structure. Most of the valuable fire-clays, ka- thirty-six ISOGEOTHERM HYPOTHESIS olins and soap-stones or commerce, accompany coal and iron ore in their occurrence, snowing us the chemical changes that occurred, when the silicates, etc., were forced to vacate the strata, as the latter was taken possession of hy the car- oonaceous matter in its concentration. ^L If you take a good encyclopedia, and look over the mineral reports of various countries, like for instance, the Spanish American coun- tries, where adverse governmental conditions have heretofore prevented exploitation, you may fce surprised at the large numter of regions that are reported to contain "coal and petroleum," or "coal and traces of petroleum. If you investi- gate further, you will almost invariahly find that toth these products occur in the same re- gion, most commonly in the same locality, and a personal investigation -will disclose that those pro- ducts occur in the same general horizon, with the coal above the petroleum, and this, notwithstand- ing that the strata in which those minerals oc- cur, are of the greatest variety of geologic age. 4L I n some petroleum regions, there are only slight traces, or manifestations of coal, so far dis- covered; and in some coal regions, perhaps the thirty-seven ISOGEOTHERM HYPOTHESIS oil is not in sufficient quantity to be profitable, but this sbould not detract from the significance of the apparent relationship. 4L I n Great Britain, petroleum occurs in small quantities under the coal at some points, but it is of little value, being mostly of the oil shale variety, which has to be mined before it can be distilled. It is here that the coal bearing de- posits, being confined within narrow geological limits, first gave the name "carboniferous to the strata. The most important of the North American coal deposits were then exploited, and it so happened that they were in strata of simi- lar age, as nearly as could be determined; and it was then that the belief was formed, that there could be no coal of any considerable value, out- side of that series of rocks, and it began to be noticed that there seemed to be a relationship between the coal and petroleum. However, there was no getting around the fact that the Appalachian, and Middle \Vest important coal deposits occurred throughout a stratagraphic scope of many thousands of feet, with the oil paralleling the coal at some hundreds of feet below. The coal of \Varren and McKean counties, in thirty-eight ISOGEOTHERM HYPOTHESIS northern Pennsylvania, occurs in a plane of stra- tification, which, if continued south, would un- derly the various oil containing strata in south- west Pennsylvania. No coal, however, was ever found under oil, despite the fact that many deep (hut futile) wells were drilled in middle and southwestern Pennsylvania in search of the oil, which, it was thought, ought to occur in continuation of the plane of stratification of the northern oil deposits. ^i, In connection with this parallelism of the coal and oil horizons, it is well to rememher that in many oil fields, the oil occurs too near the surface to admit of a coal horizon above it, the strata where the coal belonged having been eroded away ages ago. 4L No doubt the same coal horizon is represent- ed by the coal of Pennsylvania, Ohio, Michigan, Indiana, Alabama, Kentucky, Virginia, ^Vest Virginia, Tennessee, Illinois, Missouri, Iowa, Kansas, Oklahoma, Texas, and perhaps other states. Oil occurs under the coal in all these states with the possible exception of Michigan. The strata in which these products occur, in this great area, can not by any stretch of the imagin- thirty-nine ISOGEOTHERM HYPOTHESIS ation be considered syncronous, or continuous, and altho the coal and oil occur in patches only, with often wide areas that are barren, there can be no doubt that they represent on a grand scale, a former isogeotherm throughout this immense region. CL Petroleum also occurs under coal, in \Vy- oming and Utah: and at several places in Cali- fornia, coal of an inferior kind occurs, if not directly ahove the oil, at least in continuation of the general horizon of carhonaceous products. CL I wish particularly to call attention to the occurrence of coal in parallelism with petroleum throughout regions having surface strata of var- ious ages, and the continuance, or at least core- lation of the coal or petroleum horizons in strata of one age, to strata of a different age in ad- joining locality or region. Also to the fact that the horizons of those products, altho each may consist of several deposits overlying each other, both maintain their identity, and maintain an orderly distance apart over a considerable re- gion. 4^ ^A^here the oil containing horizon has a con- siderable scope, the coal horizon also, has a con- forty ISOGEOTHERM HYPOTHESIS sideratle scope, and the two maintain a great distance apart; as in southwest Pennsylvania, and northern Vv est Virginia, where the two horizons are about 2,000 feet apart from center to center. In Illinois, where there is only a few hundred feet between them, the coal and petroleum are each confined to one or two deposits close together. 4^ Many textbooks and geological reports and bulletins, altho edited by persons who "never looked at it that way," are useful in showing that oil and coal occurrences in their aggregate continuance, represent former isogeotherms. 4^ Most, if not all the metallic minerals, seem to occur in horizons, independently of the plane of stratification, like petroleum and coal. That is, each deposit of exactly like variety, (if there be any two such in nature) has required like con- ditions of covering, heat, and other like condi- tions of environment. Carbonate iron ores: hem- atite, limonite, magnetite, etc., in infinite variety, occupy a definite position in relation to each other and to coal, lying above the coal at vary- ing distances according to type, while another, and vastly different kind of iron occurs well down in the metamorphic rocks, where the heat forty-ne ISOGEOTHERM HYPOTHESIS was evidently sufficiently great to deposit it in a volatile condition analogous to our treatment of iron in the arts. The before mentioned iron ores which are plainly deposits of former gravel and sandrock, the substance of which has turned more or less into iron, may be said to be of "chemical" origin, but the fact that they occur in a definite limited horizon, independently of the plane of stratification, shows that their oc- currences represent, in their continuance, a form- er isogeotherm. The carbonate iron ores are popularly supposed to be precipitates from iron- charged water that percolated into the strata that afterwards became iron, but consideration of the fact that coal and iron carbonates so fre- quently occur together, must show that there is a relationship between them. (^ Limestones of like type also occur in limited horizons: and, while a massive limestone deposit may closely adhere to the plane of stratification for a hundred miles, if it has extended out of conformity with the former isogeotherm, it will have changed its type; and as like as not another deposit, 500 or 1000 feet above or below the first, -will have developed into the original type forty-two ISOGEOTHERM HYPOTHESIS of the first deposit, defining the course of the former isogeotherm. It is more common, how- ever for a massive limestone to occur out of con- formity 'with the heading, when people who do not suspect its true nature often use it as a hase for the determination of the position of other strata, with much confusion of understanding. CL The text-books tell us that limestone is main- ly or largely composed of the remains of marine creatures that livedand died in great numbers at the time the said limestone was forming at the bottom of the ocean. But much contemplation and observation of limestone, (which is a very in- definite term,) shows us that it does not contain evidences of marine forms in greater number, or more frequently than other sedimentary strata. CL It is common to see massive limestone, very pure and hard, without a trace of marine forms throughout its extent, while a few hundred feet under it will be found shales, sands and con- glomerates, containing numerous shells of marine creatures, composed not of lime, but or silica. The Niagara limestone at Niagara Falls is typi- cal of the kind that occurs so frequently in, or just above the petroleum horizons. To the forty-three ISOGEOTHERM HYPOTHESIS southwest for hundreds of miles, the "Niagara" maintains its type because it conforms to the lines of a former isogeotherm, tut to the south, it soon loses its identity, because it dips below the oil horizon. The mile-deep well near Pitts- burgh did "not reach it, to the astonishment of the geologists. CL ^Vhere carbonate of lime is abundant in the horizons of coal and petroleum, it has changed shales into hard dolomites or other hard lime- stones; sand has been turned into sandstones; peb- bles have been turned into conglomerates; etc. Four or five thousand feet higher in the series it occurs in a more or less chalky form, often in the form of concretions, which occurrence would absolutely forbid their formation by accumula- tion of limy marine shells. Many other forms of limestone occur so irregularly as to utterly preclude their formation in this way. If lime can leave, or be driven out of fossil shells through chemical action, can it not be driven indefinite distances through strata, to redeposit in strata containing no trace of marine forms? CL Did petroleum, coal, limestones of similar type, and other products, occur evenly and con- forty-four ISOGEOTHERM HYPOTHESIS tiimously in their proper horizons, then, the fact of thsir occurrence on lines of former isogeo- therms would he self -evident, tut that perplexing old alchemist, the earth, has grouped them in such an irregular way, owing to causes that are not yet understood, that it requires quite an application to the subject to properly view them in this regard. Sometimes the carbonaceous matter in a series of deposits has apparently all, or nearly all, entered into combinations to form a limestone of massive form. At other places it has gone almost ex- clusively into an immense coal vein, or into a number or coal veins or beds, occurring one above another, sometimes several hundred feet apart, and varying in their character of compo- sition, which probably accounts for their position vertically in the zone or horizon. At other places, nothing but petroleum is in evidence, (this, however, is rare.) Elsewhere, salt alone, or iron carbonates are found. Vv here all, or several of these products occur, they always occur in their regular order, the petroleum oc- curs below the coal, the salt between the two, or possibly sometimes below the oil. The iron forty-five ISOGEOTHERM HYPOTHESIS ore, if a typical hematite, closely adheres to the zone of the coal, but if a limonite. it may occur 2000 or 3000 feet above it. Limestones of like type always are confined to a certain position in relation to the other products, but being of vari- ous degrees of pureness and composition, they of course have a range vertically of many thousands of feet, as might be expected. d, Many other non-metallic minerals of like type occur in definite limited horizons, independ- ently of the plane of stratification. Mineral nitrates occur in this way. Their occurrence in quantity is, however, limited to regions where there is very little or no rainfall, as, if there was enough water to reach down in the earth, it would quickly dissolve the valuable salts. Common salt, soda, etc., are found outcropping only in desert countries for the same reasons, but are now largely obtained by shafting or bor- ing through impervious superincumbent strata, below the point where the water has penetrated, because, of course, there was no water in those zones or isogeotherms, until they emerged and were eroded, the original sea water with which they were charged, when they were formed, forty-fix ISOGEOTHERM HYPOTHESIS having teen dissipated as suck, before they had reached their maximum subsidence, d. The most common form of salt occurs in petroleum and coal horizons, sometimes in such enormous quantities, and in such purity, that the popular conception of its origin in desert basins must be wrong. \Vater found at great depths is almost invariably charged with some kind or other of salts which make it unfit for use. Close to the surface however, especially above the level of the deeper valleys, the cir- culation of the water in countries having a fair amount of rainfall, has removed the salts. All this evidences the truth of the theory, that the strata had subsided to where the heat or other factors of great depth and pressure, had operated to eliminate the uniformly brackish sea water that saturated the sands when the strata was formed. Sulphur and other substances that blend with coal, petroleum and many other products, could only have done so in a condition of volati- lization. d. Soils also, might advantageously be classified along lines of former isogeotherms. orty-eve ISOGEOTHERM HYPOTHESIS VERTICAL EXTENT OF MINERAL HORIZONS ^ All Jeep well drillers know by practical ex- perience, that the heat increases downward, but in some regions it increases much more rapidly than in others. Unless a flow of water is en- countered, it is difficult to get the exact temper- ature of a hole at any point, because the cool water that is constantly admitted to the hole, has a tendency to cool the rock, which, being a non- conductor of heat, is slow and uncertain about recovering its normal temperature. 4L ^vVhere the heat increases rapidly, it is thought to be owing to the strata being of a less complete non-conductive nature, than where it increases slowly. Ci^ No doubt this variation in the increase of heat applies to great depths as well as to the in- significant depth of a few thousands of feet to ^which we can penetrate with our present facili- ties. d^ If, at the time of maximum subsidence of a region, the heat increased rapidly in the isogeo- therm of deposition of volatilized carbonaceous matter, then we should expect to find the result- forty-eight ISOGEOTHERM HYPOTHESIS ing products confined to a few hundred feet ver- tically in each case, altho there would he other factors, such as the presence of other substances with which each product would have a tendency to hi end. d. If the heat increased slowly, we should ex- pect the coal for instance, to occur in a consid- erable vertical scope, a thousand feet in some ex- treme cases, like for instance, southern Pennsyl- vania, or northern \Vest Virginia, where the oil likewise occurs a couple of thousand feet he- low the coal, and like the coal, has a consider- able scope. CL \Ve must not forget about the enormous de- nudation that has occurred almost everywhere, at least wherever there is a semblance of hills or uneveness of any kind. The present surface lines in an oil or coal horizon, or region, should be regarded largely as an accidental circumstance. ^Ve frequently see a thousand feet thickness of strata outcropping in plain view, the upper por- tion of which is apparently as firmly knit by the former pressure as the bottom layers are. This shows that the weight of the one thousand feet of strata was such a small part of the whole forty-mac ISOGEOTHERM HYPOTHESIS pressure to which the strata had originally been subjected, that it made no appreciable differ- ence to our eyes. If however, we have an op- portunity of observing a few thousand feet ad- ditional of outcrop above the other thousand, we will probably be able to note a difference, ow- ing to an increase in firmness as we trace the strata downward. d. Near the Hill street tunnel, on First street, Los Angeles, Cal., there is beautifully exposed, strata tilted almost vertically, resting upon which, unconformably, of course, is a horizontal strata, -which is not much less firm than the lower one. Both series are among the most recent deposits, and constitute an object lesson of the immensity of past time. d, ^*Ve must remember that where we can trace a single series of 30,000 feet or so of strata, we must look for the petroleum and coal horizons near the top of the visible series, because the comparatively f ew thousands of feet or material that had been above them would be more crumb- ly and less compact, and hence not likely to sur- vive the denudation that had exposed the im- mense series of strata. Likewise when we ob- fifty . ISOGEOTHERM HYPOTHESIS serve a flat, or gently rolling landscape, composed of crumbly material, where the bedding can only be detected in tne most favorable locations, we may be sure that the valuable minerals, if any, are far below, excepting, of course, in a possible separate series of deposits within react of tbe surface. CL \Vbile petroleum is confined to a definite vertically limited borizon wbicb, like coal, oc- curs independently of tbe stratification, it does not occur so regularly in that borizon, being collect- ed more in spots, or irregular belts, and rarely spreads continuously over a considerable stretcb of country. Tbe fact tnat petroleum only oc- curs in porous strata, often very limited and ir- regular in occurrence, also, probably bas mucb to do with its irregular occurrence. 4L All who have read geological textbooks and official bulletins, may have noticed that the writers or editors sometimes described certain conditions, admitting that they were perplexing and inexplicable, but which are not so at all, when considered in connection with the isogeo- therm hypothesis. Several geological writers have stated that it was "a curious fact" that in fifty-one ISOGEOTHERM HYPOTHESIS the Appalachian region, or at least certain por- tions of it, the petroleum, or coal, in their successive occurrences in a certain direction, occurred suc- cessively higher, and in younger strata, or the reverse, over several hundred miles in one direc- tion. It has teen admitted that cross-bedding, and other phenomena, in strata that only admit- ted of certain definite conditions in their forma- tion, occurred in hoth coal and limestone. Of course, there is nothing wonderful in this, when we regard hoth of these products as merely pro- miscuous ordinary strata that has teen changed in its chemical contents only, but the old geologi- cal conception of their origin requires the per- formance of miracles in their behalf. STRATIGRAPHY OF THE WHITTIER OIL FIELD CL The stratigraphy in connection with the oil occurrences in the old \Vhittier oil field, al- though possessing certain general features in com- mon with all other oil producing districts, con- tains those fundamental features in such an exag- gerated aspect, that the determining of the law of the oil occurrence has seemed inexplicable and ISOGEOTHERM HYPOTHESIS past finding out, and while perhaps no other oil field has he en so much studied and described, it will perhaps interest many to get still another description, and general deductions from my obser- vations, because, perchance, they ""never looked at it that way. 41, The trend of the exposed strata in this field, is found by much investigation, to average a true east and west, but as the developed portion* which is well defined by numerous failures (at least on its northeast side,) extends in a nearly northwest and southeast direction, and is very restricted in width, at least in its northwest end, owing to the steep dip of the oil horizon, it is obvious that oil occurrence along the line of strike of the strata is not very extended, and sel- dom reaches as much as half a mile. 4L This is the feature that was so puzzling to the early operators, and many investors still have an aching void in the region of their pocketbooks, owing to failure to locate producing wells a short distance along the line of strike of the strata from good producers. CL It might be supposed that whatever was the cause of this general unconformity of the course fifty-three ISOGEOTHERM HYPOTHESIS or the oil belt to the trend or strike of the strata, the continuance of porosity in many of the oil strata, in ohliquely crossing the narrow field, would cause great irregularities in the flanks of the general oil belt. But this is not the case, the limits of the field being fairly regular, as represented by developments, oil seepages, and other surface indications; one exception, how- ever, being a considerable seepage midway of the field, and near the line of the southwestern edge of developments, the rest of the seepages being, of course, on the other, or shallow side. CL There has not been a single failure in the de- fined field, except such wells as were pinched out, or plugged -with lost tools, or by failure to shut off the water, while close outside the defined limits, there have been sunk numerous failures, and not a single productive well. All those failures on the southwestern or deep side, however, may be considered as being of insufficient depth, while the northeastern side, representing the outcrop of the oil horizon as the writer pointed out several years agois defined permanently, and nothing of any consequence can be expected there. CL This clean-cut limit of the oil field may be fifty-four ISOGEOTHERM HYPOTHESIS accounted for on the supposition that the separ- ate oil strata have little persistence or continu- ance of porosity, so that the oil has always re- mained well in its defined limits of original de- position, and indeed this seems to be the case, as seldom can any single stratum he identified with any certainty in adjoining wells. C, The old time driller in the Whittier field does not speak of "the oil sand because he knows that there is no such thing as a definite oil sand there, but there are dozens, perhaps hundreds of them, so many that it is impossible to more than give their mode of occurrence. Perhaps the oil in some of these separate strata is intercommunicable, although they seem to be separated by well defined strata of impervious stale. CL The strata in this field dip all the way from 45 degrees in the southeastern end s to vertically in the northwestern end. This is determined by observing the dip of the exposed strata at the surface, by comparing in neighboring wells the depth at which is encountered certain persistent strata that may reasonably be supposed to be continuous from well to well; and by recovering fifty-five ISOGEOTHERM HYPOTHESIS numerous pieces of under-r earnings, containing portions of the face of the hole, in which the bedding is plainly marked. V.v. The northwest end of the ^X^hittier-Puente oil field. Dots represent -wells that are, or have been producers. Outside of the area represented by the dots no profitable wells have been found. In this area, practically no failures have been obtained. Most of the wells are many years old. Development has been going on for about 15 years. Observe that the direction of the develop- ment, (which parallels the outcrop of the oil horizon) is N .\V. and S. E., although the steep-dipping, outcropping strata, trend east and west: showing a non-conformity of the oil horizon to the plane of stratification of nearly 45 degrees. CL The general trend of the kills or anti-cline conforms closely to the trend of the oil field, so that the trend of the strata cuts obliquely across ISOGEOTHERM HYPOTHESIS both. It has often been held by persons who nave not themselves investigated, that this is im- possible; that the strike of the strata must neces- sarily conform to the axis of the anti-cline, but this need not follow, as in this case there might have been, and probably was, over the whole re- gion originally, a universal dip of the strata to the south southeast before the anti-clme began to form. CL This feature of unconformity of the outcrop of the oil horizon to the horizontal trend of the strata is not at all exceptional, but nowhere else, perhaps, does it occur in such exaggerated form. If, however, we view in perspective, a profile of the oil horizon of this field as it extends into the earth in the direction of the dip of the strata, we find that the same phenomenon of unconform- ity to the plane of bedding occurs, the oil hori- zon, as in most other fields, dipping roughly about half as much as the strata does, but as the strata in this field dips very steeply, and in most other fields but slightly, the unconformity here is very noticeable, while in other fields it has not been sufficiently noticed to cause comment. CL Here we have under consideration an oil fifty-evn ISOGEOTHERM HYPOTHESIS field where the strata stands at suck a pitch that it is considerably nearer vertical than horizontal throughout the field; the field extending, not with the strata, but obliquely across it; a nar- row belt or oil producing territory with shallow wells and oil outcroppings on one side, denoting the outcropping of the oil horizon, with gradual- ly deepening wells towards the other side where the field is defined by the limitation of depth, the cost and time of drilling the deep wells being heretofore prohibitive. d, I* must be admitted that this is a very diffi- cult mafter to describe comprehensively to those who have heretofore not given it much a#ention, and people generally have somehow got the no- tion that oil is a concomitant of certain individ- ual strata, and must necessarily occur in connec- tion with those strata and nowhere else, and it must be confessed that it does appear so in an oil country like, for instance, western Pennsylvania, where, sometimes over an extent of twenty or thirty miles the oil is confined to one or two well defined strata, which can be unmistakably identified for that distance; however, if the ob- server will view in perspective 100 or 200 miles fifty-eight ISOGEOTHERM HYPOTHESIS of that country, lie must note that the oil-con- taining horizon as a whole Joes not conform to the plane of stratification. d^ Now what Joes this orJerly, I will not say regular, non-conformity of the oil horizon to the plane of stratification signify? Just this, it gives us the key to the origin of the oil, to its Jistilla- tion from helow hy the heat in the earth, anJ its final Jeposition in its original isogeotherm, or plane of equal heat, which woul J rarely or never he in exact conformity with the plane of strati- fication, anJ as the region slowly emerge J from the hot Jepths, anJ the miles of strata ahove he- came worn away, the strata contmueJ its tilting, usually on the same orJer it hegan, until the oil horizon itself hecame contorteJ anJ Jippmg, though usually not so greatly as the strata. C, The oil at Wli#ier all occurs in the regular Puente series of formation, composeJ of shales, sanJs, anJ conglomerates. Beginning generally at the base of the hills, anJ extenJing south, is a much later formation, resting unconformahly up- on the Puente. At the Leffingwell ranch this newer Jeposit extenJs into the hills in a hoJy of several hunJreJ acres, with the bo#om of the fifty-nine ISOGEOTHERM HYPOTHESIS canyons cu#mg through in places into the Puente series, which is noticeably different, even to a novice. At several other places there are de- tached patches of the later formation, which have so far escaped complete denudation. ^ This ma$er of more than one series of de- posits, however, is of liftle interest or value to the oil man, for the lines of demarkation mapped out by geologists, separating the supposed serial deposits with their fanciful names, (generally bor- rowed from far away Britain), is no barrier whatever to the orderly course of the petroleum, and coal and perhaps other horizons, which, scorning such insignificant obstacles, keep right on into and through many named deposits. Even truly separate series resting unconformably up- on each other, providing they had reached suf- ficient subsidence, exert no influence whatever upon the orderly course of those horizons. C^ The continuation of the ^!Vhi#ier field, or rather the outcrop, is in an E. S. E. direction, along the Puente hills, and, while the whole oil horizon does not outcrop portions continuing over the summit where the hills are lowest it outcrops sufficiently completely, to form a line of sixty ISOGEOTHERM HYPOTHESIS seepages to beyond Olinda, about fifteen miles. d^ This outcropping represents the edge or an immense oil field which has Heretofore teen con- sidered too deep to successfully operate to any great extent, except near the outcrop, which is somewhat irregular, owing to its non-conformity with the steeply dipping outcropping strata. These strata as at \Vhi$ier, trend east and west the whole distance, while the line of seepages along with the groups of wells at ^Vhi$ier, run S. E.; a few miles S. E. of that point, bend more easterly, and continue about E. S. E. to Olinda, being considerably out of conformity with the bedding the whole distance. ^ Recent development, in closing up the gaps between the groups of producing wells, has a tendency to show that what was apparently a succession of overlapping oil strata a thousand or so feet apart, with barren strata between, is really a practically continuous outcrop of the whole oil horizon, altho somewhat irregular, ow- ing no doubt to the irregularity of porous strata, in which only, the oil can occur, and which is absent at points along this grand outcrop. C At other oil fields in California there are sifcty-cm ISOGEOTHERM HYPOTHESIS somewhat like conditions, the oil horizon rising ahruptly from a great depth, and outcropping in steeply dipping strata, the porosity of the oil sands not being very continuous or persistent, so that altho some of the minor oil deposits have been destroyed by surface water having entered them, the near-by deposits are uninjured. C. A remarkable feature of this Whi#ier-Pu- ente oil field is the great diversity in the char- acter of the oil: especially in the gravity, which ranges from a tarry fubstance too heavy to pump, up to 36 gravity (Baume.) It used to be thought that the basic oil was very light, and that the heavier oils had become so through the loss of their volatile constituents, but since the field is better developed, it appears that the light- est oils are the lowest in the oil horizon, and as a rule the heaviest are highest in that horizon. It seemed difficult at first to formulate such a rule, because, where the oil horizon cut diagon- ally across the edge of the steeply upturned strata, the differing oils seemed to be sandwiched in the oil horizon in a bewildering manner, but it is now plain that those deposits that are con- fined to the N. E. side, or underside of the oil ISOGEOTHERM HYPOTHESIS horizon, are always much lighter and more val- uahle than the more persistent deposits that cut clear across the oil horizon, and the very tarry oil is confined to the top of the oil containing horizon. In fact, in nearly every well in Cali- fornia, traces, or small showings of tar are en- countered, usually many hundreds of feet above the main bodies of oil, and operators generally have learned to pay no aftention to such showings, as they are usually of no great extent. The very light oil deposits also, are generally of limit- ed extent, and the wells rarely hold up as well as those of medium gravity. It must not he as- sumed, however, that because a strata yields a very heavy oil, that deeper drilling will neces- sarily develop a deposit of light oil immediately under, although the chances are such as to be well worth the cost of making an extra thousand feet of hole, -where there is a considerable area to be proven. In other California oil fields it is also recognized that light oils are most likely to be found lower than the heavier oils, but the practise of classifying each level at which oil is found, as a separate oil "horizon," has confused the mafter. ixty-three ISOGEOTHERM HYPOTHESIS CL People who object to the subsidence, or iso- geotherm hypothesis of petroleum origin, refer to the enormous amount of deposit it would ne- cessitate ahove the petroleum zones in order to secure the necessary heat to properly distill the product found therein, and ask for proof that there were two or three miles or so of deposit ahove it. CL At several places in California, notably in the Coyote Hills district, it is more than 4,000 feet to the oil, and the only reason it is not found deeper at other places is ohviously hecause that is close to the practical limit that can he reached without an outlay or cost which would he pro- hibitive. Indeed it is only the last few years that it has been considered practicable to go more than half that distance in California, and wells of 4000 feet, cost on an average, at least thirty thousand dollars. C, The strata, where it is cut into, 4500 feet above the oil, has the same general appearance and texture, as it has in the oil horizon, or be- low it. The inference is, that if there had not been several times that much superincumbent de- posit at the time of maximum subsidence, the eixty-four ISOGEOTHERM HYPOTHESIS difference in texture in that 4500 feet of strata would be noticeable. Then the temperature at 4000 feet depth, is in the Coyote field, about 170 F. which would amount to about one degree increase for 40 feet. The deposit is tertiary and the universal denudation must have been very great, as in such a friable formation, the rate of elevation would hardly much exceed that of denudation. 4L But what is especially worthy of our atten- tion is the enormous amount of denudation that would occur in such a formation, before it emerged above the surface of the ocean. Indeed it never would have so emerged, containing the oil horizon intact, had it not been protected by immense masses of coarse flinty sand, the sittings from the thousands of feet of denuded superin- cumbent strata; and the like masses of similar sand that everywhere protect the emerging beaches, give eloquent testimony to this univer- sal denudation by the waves. Nature in her destructive operations, takes no account of eco- nomic values, and it seems that recently formed oil strata like those of California, that have not had sufficient age to harden them, are as often as ixty-firc ISOGEOTHERM HYPOTHESIS not, entirely cut to pieces by the wave erosion in their emergence. Examples of suck oil hori- zon erosion can be witnessed at Point Firmin, and Summerland; and the sbore of tbe Pacific for hundreds of miles is littered witb splasbes of aspnaltum and paraf me, that come from the erod- ed bottom. CANADA, LAKEER:E. WAPREN.TIDIUTE, OILOTY, Diagram showing the successive occurrences of petroleum and coal across western Pennsylvania. The upper series of short line* represent the coal, and the lower ones the petroleum horizons. 4 Millions of dollars Lave been needlessly wasted in drilling futile exploration wells in the last 60 years, in insistent attempts to find oil in strata that were supposed to correlate with strata tbat are oil bearing in a distant locality, but which are entirely out of tbe oil containing horizon. ixt^-six ISOGEOTHERM HYPOTHESIS Those errors are made mostly where the oil fields are being developed in the direction of dip of the strata, where the oil horizon generally passes gradually from a lower, to a higher strati- graphical plane. For instance, where the oil is obtained at, say 1000 feet depth, and it is known that at 3000 feet depth, would be encountered strata, that correlated with oil containing stra- ta in a distant locality. Parties frequently sink wells to the lower level, when that great depth would he entirely out of the possible oil contain- ing horizon for that locality. This has been go- ing on ever since the writer was a boy, and he never heard of an instance where such a venture was successful. ^L After going a few hundred feet below the known oil containing zone, the chance of en- countering oil is less "with every foot drilled, re- gardless of how prolific the strata are elsewhere. CL The great irregularity of the occurrence of petroleum in it's horizons, and it's tendency to occur in extremely prolific deposits on or near the summits of anti-clmes, may be accounted for in this wise. As the heated strata subsided, and was being ""skimmed of its volatilized, carbon- eixty-evn ISOGEOTHERM HYPOTHESIS aceous and other matter, the volatilized mat- ter that was to form the petroleum, would en- counter certain strata which would offer more resistence to its progress upward than other stra- ta, and it would develop a tendency to follow lines of least resistence up under the shelving strata, thus gathering it constantly towards the apex of the anti-clines, or towards a region of less vertical resistence. CL There are cases, on the edge of large sedi- mentary areas, where quantities of oil have heen found abutting on, and over granitic masses. In Placentas Canyon, near Newhall, California, oil has heen found in small quantities where the wells were started in granite. Possihly the granite had heen elevated, and tilted over atop of the steeply dipping sedimentary strata which is near at hand. ^L The volatilized matter that formed coal, seemed to have more affinity for finegrained im- pervious strata, where it generally finally lodged, and which would offer little resistance to its up- ward movement, consequently, coal is found to occur much more evenly, and continuously in it's individual deposits or teds. 377446 UNIVERSITY OF CAUFORNIA LIBRARY