DEPARTMENT OF THE INTERIOR

UNITED STATES GEOLOGICAL SURVEY

GEORGE OTIS SMITH, DIRECTOR

4O1

LOCAL MAGNETIC DISTURBANCES

AND THE

GENESIS OF PETROLEUM

BY

GEORGE F. BECKER

LL * -

Sf

co

o

WASHINGTON

G O V K K N M K N T P 111 N T I N O O F F I C V\

1909

CONTENTS.

Page.

Very questionable origin of the hydrocarbons.....'......................... 5

Argument for organic origin............................................... 5

Argument for inorganic origin............................................. 7

Digression on the origin of ammonia................................... 7

Associations of hydrocarbons.......................................... 9

Conclusion, that hydrocarbons accompanying igneous rocks are inorganic. 12

Importance of inorganic hydrocarbons..................................... 14

Theories of inorganic genesis all unsatisfactory............................. 15

Facts bearing on carbide of iron theory.................................... 19

Irregular compass declination in petroleum fields........................... 22

Conclusions.............................................................. 24

ILLUSTRATION.

Page. 

PLATE I. Map showing petroleum deposits and lines of equal magnetic

declination for 1905 _________________________ 22

.RELATIONS BETWEEN LOCAL MAGNETIC DISTURBANCES AND THE GENESIS OF PETROLEUM.

By GEORGE F. BECKER.

VERY QUESTIONABLE ORIGIN OF THE HYDROCARBONS.

No question in geology is more obscure than that of the origin of 

the numerous natural hydrocarbons commonly classified as asphalt, 

ozokerite, petroleum, and natural gas. Certain facts of occurrence 

and certain results of experiment are indeed established, but the interpretation to be placed upon them is so doubtful that the conclusion reached may almost be said to depend on predilection. A great 

number of the more important hydrocarbons found in petroleums 

can be produced artificially from organic substances, such as coal, 

wood, and fish oil, while identical or closely allied hydrocarbons result from the interaction of inorganic substances, such as cast iron 

and chlorhydric acid. In many places petroleum is closely associated with fossiliferous strata; but hydrocarbons likewise exist in 

meteorites and in volcanic gases; they are even expelled by heat from 

granite and basalt. The most orthodox opinion at the present day 

is that a part of the natural hydrocarbons is of organic origin and 

a part also of inorganic origin; but when it comes to estimating the 

relative importance of the two portions there is no approach to 

unanimity. Before making a suggestion, which in this connection 

appears to be of interest, it may be well to outline the arguments for 

the opposing views.

ARGUMENT FOR ORGANIC ORIGIN.

Mr. Clarice has given an excellent digest of the evidence of organic 

origin in his " Data of geochemistry." It will be still more briefly 

summarized here. That hydrocarbons are produced by the destructive distillation of either vegetable or animal matter has long been 

known. The manufacture of illuminating gas from coal exemplifies 

the process. In 1865 Warren and Storer a made paraffins, olefines,

" Mem. Am. Acad., 2d ser., vol. 9, 1865, p. 177.
O . LOCAL MAGNETIC DISTURBANCES

and aromatic compounds in mixture (thus practically manufacturing 

petroleum) from saponified fish oil; and in 1888 Mr. Engler a formed 

similar compounds under pressure from unsaponified fish oil. Later 6 

the same chemist obtained hydrocarbons by distillation from vegetable oils. All of these results have been abundantly confirmed by 

other experimenters.

Many observed associations also point to organic genesis. Marsh 

gas (fire damp, methane) is the most volatile member of the paraffin 

series. It is generated in swamps and in coal beds and forms the 

greater part of natural gas. Rotting seaweeds likewise emit it, 

and there is some reason to believe that salt water by delaying putrefaction is favorable to the formation of hydrocarbons; at any rate 

brine and petroleum are often associated. Some petroleums, especially those of California, contain nitrogen bases, which tends to show 

that the oil has been derived from animal matter. According to Mr. 

F. Hornung," the hydrocarbons of the Zechstein formation in the 

Harz region are derived from fish remains. In his opinion the fish 

were killed by brines of salt lagoons and their fats saponified by 

salts of lime, magnesia, and ammonia. If so, Warren and Storer's 

experiments completely illustrate the process.

The association of petroleum with sedimentary strata is well 

known; in fact, oil is found in large quantities only in stratified rocks. 

In a word, as Mr. Clarke d says:

Wherever sediments are laid down, inclosing either animal or vegetable 

matter, there bitumens may be produced. The presence of water, preferably 

salt, the exclusion of air, and the existence of an impervious protecting stratum of clay seem to be essential conditions toward rendering the transformation possible. Seaweeds, rnollusks, crustaceans, fishes, and even microscopic 

organisms of many kinds may contribute material to the change. In some 

cases plants may predominate; in others animal remains; and the character 

of the hydrocarbons produced is likely to vary accordingly, just as petroleum 

varies in different fields.

Granting the organic origin of petroleum, its accumulation may 

be accounted for in some measure by flotation, since it is lighter than 

water; but capillary displacement by water appears from the studies 

of Mr. David T. Day to be much more efficient than buoyancy. The 

presence of organic hydrocarbons in massive rocks might be ascribed 

either to capillary infiltration or to the incorporation by massive 

rocks of strata carrying organic matter. Similarly it is possible that 

the evolution of hydrocarbons in volcanic gases depends upon the 

distillation of organic matter by volcanic heat, and the same explanation may be applied to the marsh gas which is brought to the

« Ber. Deutsch. chem. .Gesell., vol. 21, 1888, p. 1816. 

6 Cong. internat. du pe"trole, Paris, 1900, p. 20. 

0 Ber. Deutsch. geol. Gesell., vol. 57, 1905, p. 538. 

* Data of geochemistry, 1908, p. 640.
AND GENESIS OF PETEOLEUM. . . 7

surface by hot springs with or without boracic acid. Even the 

asphalt lake of Trinidad may owe its origin to distillation or 

eliquation.

ARGUMENT FOB INORGANIC ORIGIN.

Of the rival hypotheses, that which ascribes to oil an inorganic 

origin is the less fashionable, and for that reason I shall discuss it 

somewhat more fully, though without any attempt at exhaustive 

treatment. Very famous men of science, however, have adopted this 

explanation as the more probable, and of these observers the first, so 

far as I know, was Alexander von Humboldt.

On August 12, 1805, Humboldt and Gay-Liissac witnessed a great 

eruption of Vesuvius; and at times they found the prevailing smell 

wafted from the crater bituminous. Humboldt had also noted in 

literature three cases in which a pleasant smell (Wohlgeruch) attended eruptions. " I put these few observed facts together," he 

says, " because they help to confirm the close connection of all manifestation of volcanic activity, the connection of brine-naphtha wells 

with real volcanoes." a This was a very long shot, even though aimed 

by the eye of genius.

Much evidence in favor of Humboldt's view has accumulated during the past century, however, and I think it can now be shown that 

such hydrocarbons as are immediately associated with volcanic or 

intrusive phenomena have an inorganic origin. The relative economic importance of the organic and inorganic oils is another matter. 

So also is the chemical theory of the relations of inorganic oils to 

other minerals.

DIGRESSION ON THE ORIGIN OF AMMONIA.

Most intimately connected with the origin of hydrocarbons is the 

derivation of the ammoniacal compounds emanating from volcanoes. 

In ordinary experience the source of ammonia is organic, and it is 

impossible to pass a stable without being reminded that ammonia is 

one of the commonest products of decay. It was therefore very natural that the pioneers in the investigation of volcanoes, such as 

Bunsen, .should have regarded the ammoniacal fumes and the incrustations of ammonium chloride so abundant at active vents as due 

to the action .of hot lavas on organic matter; but a comparatively 

recent investigation by Mr. J. Stocklasa seems to demonstrate that 

the ammonia is of inorganic origin, as others had suspected from less 

complete evidence.

0 Cosmos, vol. 4, p. 274. This volume appeared in 1858. Whether Hnmboldt had referred to the matter in any earlier publication I do not know. I assume that his opinion 

was formed at the date of his observation. L. von Buch noted the smell of volatilizing 

petroleum (Bergoehl) at Vesuvius nearly a year before Humboldt (Geog. Beob., vol. 2, 

1809, p. 216), but did not draw any general inference.
8 LOCAL MAGNETIC DISTURBANCES

Mr. Stocklasa a made chemical tests in the field during the progress 

of the eruption of Vesuvius in April, 1906, supplemented later by 

laboratory work. He found that the gases emitted always contained 

chlorhydric acid and ammonia; that the glowing lavas are shrouded 

in a veil of ammonium chloride vapor even far away from any vegetation; that lava still hot from the crater yields (when powdered and 

leached with water) notable quantities of ammonium chloride; that 

the yellowish smoke forming the " pine tree cloud " above the crater 

of Vesuvius consisted-chiefly of ammonium compounds; and, finally, 

that from the more solid fresh lavas, especially the olivine bombs, 

ammonia may be expelled by heat alone.

Though eruptions break out at various points on the cone of Vesuvius, analogy justifies the belief that it has but a single conduit or 

neck through which the eruptions of many thousand years have 

reached the surface. Any fossiliferous strata through which the conduit may pass must have been baked out long ago and must have 

yielded up any products of distillation with which the sediments 

could part. It thus seems quite impossible that the immense ammoniacal product of this volcano can have an organic origin.

Mr. Stocklasa considers it probable that the origin of the ammonia 

is referable to nitrides, especially that of silicon, which is easily prepared, but not known as an actual mineral. A nitride of iron, however (now known as silvestrite), was found at Etna by Orazio 

Silvestri 6 in 1875.

Others had preceded Mr. Stocklasa in maintaining that the ammoniacal emanations of volcanoes are due to the presence of nitrides in 

the magmas; for example, Mr. Armand Gautier c and Mr. A. Brim/1 

The last obtained ammonium chloride by calcination from all lavas, 

acidic or basic, with which lie experimented. His list included specimens from Krakatoa, Chimborazo, Bourbon Island, and Hecla, as 

well as a long suite from the Mediterranean. Mr. Brun also anticipated Mr. Stocklasa in asserting that the smoke of volcanoes is 

largely composed of chlorides.

Ammoniacal compounds appear to be almost or quite invariably 

present in volcanic emanations. They are also found, I believe, without exception in boric acid springs, or suffoni, and in many other 

thermal springs. If ammonia were only occasionally associated with 

volcanic phenomena and igneous rocks, its presence might be ata Ber. Deutsch. chem. Gesell., vol. 39; 1906, p. 3530.

* Pogg. Annalen, vol. 157, 1876, p. 165. Silvestri lays especial emphasis on the formation of ammonium chloride within the great crater of Etna where, he says, an organic 

origin for this substance is not to be thought of.

"Bull. Soc. chim., 3d ser., vol. 29. 190'}, p. -191.

"Arch. sci. phys. et nat., vol. 19, 1905, pp. 439, 580.
AND GENESIS OF PETROLEUM. 9

tributed to adventitious organic matter. The evidence of the inorganic origin of the ammonia emitted by volcanoes is cumulative but 

conclusive.0

ASSOCIATIONS OF HYDROCARBONS.

After Humboldt's qualitative detection of hydrocarbons at Vesuvius their study seems to have been neglected for a long time. Bunsen l indeed looked for hydrocarbons at Hecla, but in vain. In 1856 

Ch. Sainte-Claire Deville found them on the flank of Etna near Aci 

Eeale as gaseous emanations. 0 In the main crater he detected no 

hydrocarbons, a fact which he attributed to combustion in the volcanic hearth. Fouque first actually collected hydrogen and marsh 

gas from an incandescent crater, that of Santorin.** .He considered 

the circumstances at this locality peculiar in that the atmosphere had 

uncommonly little access to the gases on their way to the vent. As 

a rule, in his opinion, a volcanic cone is so porous and so charged 'with 

air that combustible gases are consumed in the heart of the mountain. 

He thus agrees with Deville., and Mr. Stocklasa holds a similar opinion. From this point of view an ordinary volcano would resemble 

a Bunsen burner in which the flame has " struck back." Since Deville's first investigations hydrocarbons have been found at Vesuvius, Etna, Santorin, Terceira Island (in the Azores), and at Pelee by 

Fouque, Gorceix, Silvestri, and Moissan. 0 Hydrocarbons have also 

been detected spectroscopically in the gases 0f Kilauea by Jannssen f 

and by Libbey.^ Mr. Stocklasa, whose investigations on the ammoniacal products of Vesuvius were referred to above, promised a 

special paper on the hydrocarbons, but this I have not succeeded in 

finding. Pie states, however, that the lavas contain hydrocarbons, and 

he attributes to their combustion the steam and carbon dioxide of the 

vapors. 7' In short, it seems only needful to.look for hydrocarbons 

under favorable conditions at volcanic vents to find them in the gases. o

Ch. Sainte-Claire Deville was a pioneer in the examination of the 

gases liberated by heat from massive rocks. " Obsidians," he says, 

" are well known to be due to the rapid cooling of lavas, especially 

those rich in silica. Now, the greater part of the obsidians still retain 

water, sodium chloride, and bituminous or ammoniacal substances,

" Mr. Clarke, remarks Stocklasa, " has clearly shown tliat the nitrogen of lava is an 

original constituent and not of organic origin." Data of geochemistry, p. 222.

"Annalcs chim. phys., 3d ser., vol. 38, .1.853, p. 2.1.5.

c Compt.'Rend., Paris, vol. 43, 1,856, p. 359.

'' Santoriu et ses eruptions, 1870, p. 220.

" Mr. F. C. Lincoln (Econ. Geology, vol. 2, 1.007, p. 258) gives 50 analyses of emanations 

with references.

r Compt Rend., Paris, vol. 07, 1883, p. 002.

v Am. .Tour. Sci., Scl ser., vol. 47, 1804, p. 371.

" Chem. Zeitung, 1006, p. 740.

3705 Bull. 401 09 2
10 LOCAL MAGNETIC DISTURBANCES

and if the}' are rapidly heated to a temperature well below the melting point, they swell up, becoming extremely porous, passing, in short, 

into the condition of pumice." a Mr. Brun has repeated and extended 

this investigation.6 From a Lipari obsidian he dissolved out with 

ether a vaseline-like grease, and by the same method he obtained 

an oil from Vesuvian ash of 1904 which floated on water. He found 

hydrocarbons abundant in Stromboli lavas of 1901 and in Santorin 

andesite of 1866. Even an obsidian from Plomb du Cantal (Auvergne), the date of which is of course unknown, yielded, hydrocarbons copiously. In later investigations Mr. Brun c found hydrocarbons in the ash or cinder of two volcanoes in the Canary Islands and 

of four volcanoes on the Island of Java. The portion of Java north 

of the volcanic belt contains numerous pools of petroleum, and Mr. 

Brun says he is forced to admit that this petroleum is of eruptive 

origin, but he does not give his reasons for this conclusion. Silvestri actually found bubble-like pockets in the lava of Etna containing solid paraffins and liquid oil.d

It is difficult to draw the line between active volcanism and solfatarism. Most of the cases in which hydrocarbons can be shown to 

escape in volcanic districts are to be classed as solfataric, for incandescent vents are hard to approach, and the gases if present would 

inflame. The bitumens of the Auvergne are probably solfataric. 

The association of lava and bitumen in that region is very close, and 

the basaltic tuffs, or peperites, which in many cases form volcanic 

necks, are heavily impregnated with hydrocarbons. The most famous 

of these rocks is the bituminous tuff of Puy de la Poix. It is noteworthy that the volcanoes of the Auvergne rest on a great granite massive, and in this rock actual veins of bitumen occur.6 Solfataric, too, 

are the occurrences of bitumens at quicksilver deposits, for hot water 

and gases pour through some of them, while the extreme similarity of 

most of these ore deposits indicates community of origin. In every 

quicksilver-producing district in California bitumens are present, 

usually and perhaps always members of the paraffin series. They are 

found with the ore embedded in hydrous silica. Bitumens also 

accompany the quicksilver ores in Texas, in Rhenish Bavaria, at 

Idria, at Monte Amiata, and at Almaden/ There is an especial and 

unexplained affinity between bitumen and cinnabar/ an ore which 

has undoubtedly been brought to the surface in solution from great 

depths.

n Sur les emanations volcaniques, Paris, 1857, p. 14. 

b Arch. sci. phys. et nat., 4th ser., vol. 19, 1905, p. 589. 

c Bib. univ. arch, des sciences phys., vol. 27, 1909, p. 113. 

" Gazz. chim. ital., vol. 7, 1877, p. 1.

" See De L'Apparent, Traite" de geologic, 5th ed., 1900, pp. 541, 1786 ; also Geikie, Textbook, p. 357.

f Quicksilver : Mineral Resources U. S. for 1892, U. S. Geol. Survey, 1893.

» Paraffins partially precipitate mercuric sulphide from its solutions in alkaline sulphides.
AND GENESIS OF PETE OLEUM. 11

The diamonds of South Africa occur in volcanic necks, and it is 

now generally acknowledged that the gems are native to the subsilicic, 

peridotitic rock known as kimberlite.0 In this rock Moissan found 

carbonado and graphite, which was more abundant than diamond.6 

Sir Henry Koscoe also examined the kimberlite. A quantity of it 

was powdered and digested Avith ether. " On filtering and allowing 

the ether to evaporate," he says, " a small quantity of a crystalline, 

strongly aromatic body was obtained. This substance was very volatile, burned easily with a smoky flame, and melted at about 50° C." c 

There can be no doubt, I take it, that these necks extend downward 

to a depth of many miles.

The famous Tuscan boracic " suffoni," or fumaroles, emit gases. 

They were examined as early as 1858 by Deville and Le Blanc,'* and 

without exception they were found to contain hydrocarbons. They 

have repeatedly been analyzed since that time, with a similar result.6

All the suffoni appear to carry ammoniacal compounds also, while 

boric acid is characteristically of volcanic origin. If any line can be 

drawn between suffoni and the boric, ammoniacal asphalt lake of 

Trinidad I do not know how to do it.

Massive rocks at a distance from active volcanoes or distinctly 

solfataric phenomena contain hydrocarbons. At some points masses 

of solid or liquid oils exist in ancient-massive rocks, but these may 

perhaps be derived from extraneous sources. Mr. W. A. Tildenf 

showed, however, that granite and gabbro, as well as basalt, when 

heated to redness, give off gases in volumes several times as great 

as that of the rock itself, methane being one of the educts. The 

granite developed about a twelfth of its own volume of marsh gas 

and gabbro an eighth. Mr. Armand Gautier ° has also analyzed the 

gases driven off by a red heat from granite, granitoid porphyry, and 

ophite, getting about one volume of methane to seven of the rock. 

If the unit volume is taken as a cubic mile, these figures become impressive. In what form the hydrocarbon exists in the rock before 

heating is uncertain, but it can hardly be merely adsorbed (or condensed on surfaces), for pulverization scarcely reduces the quantity. 

This behavior seems inconsistent with the idea that the presence of 

methane is due to the diffusion of a gas of organic origin or to the 

infiltration of exotic oils.

For the sake of completeness, the presence of methane in thermal 

springs not referable with certainty to volcanic action may be men-

" I could not find the least evidence of change even in the sharpest splinters of shale embedded in the lava. Science, vol. 6, 1897, p. 664. 

6 Compt. Rend., Paris, vol. 116, 1893, p. 292. 

c Proc. Manchester Lit. and Phil. Soc., vol. 24, 1885, p. S. 

" Coinpt. Rend., Paris, vol. 47, 1858, p. 817.

"For example, by Mr. R. Nasini (Gazz. chim. ital., vol. 28, 1898, p. 100). 

f Chern. News, vol. 75, 1897, p. 169. 

o Aunales des mines, 10th ser., vol. 9, 1906, p. 310.
12 LOCAL MAGNETIC DISTURBANCES

tionecl. There is a growing belief that springs of high constant temperature and constant flow emanate from points below the level to 

which stratified rocks usually extend, and that the water is either 

"juvenile " (i. e., of recent formation) or magmatic. This opinion is 

founded on the impossibility of accounting for the composition of 

such springs as those of Bohemia on the hypothesis that the waters 

are vadose.a Mr. F. W. Clarke 6 has thrown new light on this subject by showing that all the sodium of the sea and the sedimentary 

strata might be supplied by a shell of igneous rock, enveloping the 

globe, .with a thickness of half a mile at the very most. Supposing 

the relative areas of land and sea always to have been substantially 

the same as at the present day, and making any reasonable allowance 

for erosion, the mean thickness of stratified rocks in continental 

areas can be only a fraction of a mile. Mechanically, also, it is most 

difficult to conceive how the purely superficial action of erosion and 

decomposition could ever result in burying the primeval rocks under 

detritus to an average depth of many thousand feet. Hence it would 

seem that typical hot springs must come from beneath the sediments. 

Now great numbers of hot springs in France, Germany, Austria, and 

elsewhere carry methane. This gas seems too common in such 

springs to be attributed to fortuitous association with organic deposits, and it is reasonable to regard it as magmatic.

CONCLUSION, THAT HYDROCARBONS ACCOMPANYING IGNEOUS 

ROCKS ARE INORGANIC.

Of all the associations of hydrocarbons briefly enumerated above, 

perhaps not a single one is incapable of explanation on the hypothesis 

that the hydrocarbons are of organic origin. It is possible to conceive that in exceptional circumstances an obsidian should have been 

kept melted within a few thousand feet of the earth's surface in an 

atmosphere of organic hydrocarbons until it had occluded as much 

of such material as can now be expelled from it by heat. So, too, it 

can be imagined that at the Puy de la Poix a fissure extends through 

the granite to some distant accumulation of organic bitumen and 

that this has merely been distilled into the peperites. So long as 

only a few isolated cases of the presence of hydrocarbons in volcanic 

educts and massive rocks were known, such explanations might 

suffice. They no longer seem sufficient or plausible. The cases of 

association are so numerous and their character is so diverse as to 

break clown the hypothesis of merely fortuitous collocation. The 

evidence is indeed mainly cumulative; but it has so accumulated and 

is so consistent as to leave only a negligible probability that the cona Vadose waters are those which have infiltrated from the earth's surface. 

h Data of geochemistry, p. 29.
AND GENESIS OF PETROLEUM. 13

nection is not genetic. I see no logical way of avoiding the conclusion that much the greater part of the hydrocarbons associated 

with eruptions or occluded in massive -rocks has an inorganic origin. 

Evidence similar to that here adduced has carried conviction to the 

minds of some of the highest geological authorities of the day. Sir 

Archibald Geikie in his text-book seems to make only a single reference to the hypothesis of the organic origin of the hydrocarbons 

attending volcanic phenomena. From the association of hydrocarbons with igneous rocks he says: a " The opinion has been formed that 

.these emanations do not proceed, as has generally been supposed, 

from the decomposition of coal or other sedimentary material of 

carbonaceous composition and vegetable origin,, but rather point to 

the existence of vast quantities of carbon combined in the interior 

of the earth with such metals as iron and manganese." In another 

passage he remarks: & " The association of mineral oil, marsh gas, and

other hydrocarbons, and of carbonic acid in old volcanic districts, 

may thus point to the continuous decomposition of such carbides by 

access of water."

Mr. de Lapparent is even more decided in the expression of his 

views. " In short, there is no doubt," he says,c " that the lavas of Santorin in a state of pasty fusion were accompanied to within 100 

meters of their, point of emergence by combustible gases originally 

imprisoned in their mass." So, again: (/ " It seems, then, that the 

basaltic emissions of the Miocene, forming a prelude to the great 

volcanic activity of the Auvergne, Avere accompanied by abundant 

outflows of hydrocarbons."

More than thirty years ago Mr. Tschermak c gave his assent to the 

hypothesis that volcanic gases are derived from the interior of the 

earth, likening eruptions to the tremendous outbursts which cause 

sunspots.

Mr. Eduard Suess f has happily characterized as juvenile the newly 

formed products of reactions which occur in volcanoes or solfataras 

and which accompany allied manifestations of energy. He thus 

classifies the carbon dioxide and the aqueous vapor of volcanoes as 

well as the formic acid detected by Fouque at Santorin. In his opinion the carbon and the hydrogen are oxidized at eruption and, thouglj 

he does not make the statement, it may be inferred that he supposes 

these elements to have been combined as hydrocarbons. Mr. Suess 

disclaims originality for the theory of juvenility, assigning the credit 

to the group of French scientists whose work has been referred to

" Text-book of geology, 4th ed., I'JOS, p. SO.

''Idem, p. 270; see also p. 185.

"Traito dc geologic, 5th ed., .1906, p. 448.

 ' Idem, p. 17S6.

" Sitzungsb. Akacl. Wien, vol.. 75, 1877, p. 151.

f Ueber heisse Quellen: Verhandl. Gesell. deutsch. Naturf. nncl Aerate. 1002, p. 133.
14 LOCAL MAGNETIC DISTURBANCES

above; but he gives it his heart}' adhesion, reinforced by observations 

of his OAvn.

This list of authorities might be extended, but that seems superfluous since it could not be improved.

IMPORTANCE OF INORGANIC HYDROCARBONS.

No direct means has yet been found of determining quantitatively 

the amount of hydrocarbons brought to the surface by eruptions. 

Much of it must burn while some escapes to make " a pleasant smell." 

It would seem to me that careful quantitative work on obsidians 

would be most likely to furnish data for estimating the percentage 

content of the magmas. If any considerable part of the water and 

carbon dioxide of eruptions is due to the combustion of hydrocarbons, as Sainte-Claire Deville, Fouque, Messrs. Suess," Stocklasa, and 

others have inferred, the total must, of course, be enormous. By 

examining the accounts of experiments it appears that ammonium 

chloride and hydrocarbons are generally referred to in similar terms, 

as if at least the order of magnitude of the two kinds of emanation 

were the same. In fact I am unable to guess from the published 

investigations whether ammoniacal compounds or hydrocarbons predominate in obsidians an<} recent lavas. Now, according to Mr. 

Stocklasa, a large part of the emissions of Vesuvius consists of ammoniacal compounds. When the scale of a Vesuvian eruption is 

borne in mind, it appears that the total quantity of these salts 

expelled is immense. Thus even if the quantity of hydrocarbons 

attending eruption were only a very moderate fraction of the am- 

. moniacal output, volcanism must be competent to yield exceedingly 

valuable quantities of hydrocarbons.*1

Even if petroleum of organic origin were exceptional, the distribution of oil might resemble its actual disposition. An accumulation of 

inorganic oil within reach of vadose water would be driven toward 

the surface by capillary displacement and buoyancy. If the surrounding rocks were intersected in all directions by cracks, the oil 

would be expelled at least in part through springs. Only an impermeable sheet of rock could prevent this expulsion, and the only rock 

found in sheets impervious to liquids is moist clay. Hence it is to 

be expected that inorganic oil when it occurs in considerable quantity should impregnate the rocks underlying clays. But such rocks 

are usually stratified and frequently fossiliferous.' Oils of organic 

origin would behave in the same way and would also accumulate, if 

at all, beneath clay. Hence the well-known fact that petroleum is 

found in these circumstances proves nothing whatever as to its origin.

" Mr. Brun asserts that the Javanese petroleum is of eruptive origin, but does not offer 

detailed evidence that it is so. Java oil is not unlike that of Pennsylvania.
AND GENESIS OF PETROLEUM. 15

From another point of view also the argument that the genesis of 

petroleum is organic because oil is associated with fossils may be 

pushed too far. In swamps the accumulation of vegetable matter is 

enormous, as everyone knows. In the open sea conditions are very 

different. The Atlantic coast of Virginia is one long beach plentifully strewn with shells, but not one in thousands of these contains a 

shellfish, and the seaweed driven up by a storm disappears with wonderful rapidity. It is safe to say that an acre of the Dismal Swamp 

carries more organic matter than 10,000 acres of Virginia beach. 

Even in tropical seas, where life is most abundant, dead animals and 

plants are rarely to be found. For the most part, living things there 

are consumed while they die. An ooze is derived from organisms 

which have perished at the surface, and their remains must in many 

cases take Aveeks to reach the bottom. What fatty tissue surface 

scavengers and the deep-sea fauna do not assimilate must be almost 

completely decomposed by bacteria during the long journey to the 

grave and the slow process of burial beneath the remains of survivors.* The simplest and best proof that there are no great accumulations of dead organic matter in the sea is that the ocean is not a 

stinking pool, but a great reservoir of purity. Hence, where notable 

quantities of oil are found in sandstones and limestones associated 

with marine fossils, as is commonly the case, there is ground for suspecting that the oil is at least exotic, if not inorganic. In shales, on 

the other hand, the presumption is the other Avay. Many mud flats 

are full of dead organisms, a part of which may in time be hermetically sealed by argillaceous matter; moreover, Avhen a small amount of 

induration has taken place Avithout desiccation the mass becomes 

impervious to allothigenetic oil.

It noAv appears certain that bituminous compounds are derived in 

part from organic matter and in part from azoic magmas. There 

is satisfactory evidence also that neither portion is economically 

insignificant.

THEORIES OF INORGANIC GENESIS ALL UNSATISFACTORY.

In the foregoing pages the attempt has been made to set forth the 

facts Avith as little reference to hypotheses as practicable. Study of 

the associations of the hydrocarbons leads irresistibly to the conclusion that notable quantities of inorganic hydrocarbons exist in nature, 

but does no.t indicate Avhether or no they are juvenile, or if juvenile 

hoAV hydrogen and carbon came to unite. The present state of 

knowledge and speculation on this subject can be briefly set forth.

a It is reasonable to suppose that the fecundity of the abysmal fauna keeps pace with the 

food supply which reaches the bottom ; " broth," as William B. Carpenter called it. For 

a lucid discussion, see Mr. A. Agassiz's Three Cruises of the Blake, Mus. Comp. Zool. Bull. 

14, 1.888.
16 LOCAL MAGNETIC DISTURBANCES

Mr. N. V. Sokolotf a has maintained that the bitumens are of cosmic 

origin, that they were inclosed in the mass of the earth and have since 

been emitted. In short, he supposes the hydrocarbons as such to be 

magmatic and to exist within the earth in solution, solid or gaseous. 

Various other writers either take this view or do not expressly dissent from it. More widely held is the hypothesis that the carbon 

exists within the earth in the form of carbides of metallic bases. 

Most of those who adopt it appear also to suppose that the hydrogen 

of the hydrocarbons is derived from water, though this does not seem 

a necessary complement of the carbide theory.

Mendeleef b was the first to suggest that in nature hydrocarbons 

Avere made from carbides, viz, those of iron. Experimentally he 

relied for support on the well-known fact that artificial irons, cast 

or wrought, if dissolved in chlorhydric or sulphuric acids, develop 

hydrocarbons. He held that the earth had an iron nucleus similar 

in composition to siderolites and believed that water at high temperatures and pressures would react as follows:

3FemCn+4mH2 0=mFeA+C,nHsm.

That steam at high temperatures produces a coating of magnetic 

oxide on iron is well known, and it is most likely that the nascent 

hydrogen would unite to some extent with the combined carbon of 

hard irons; but Mendeleef does not seem to have demonstrated this. 

Moissan objected 0 to this theory because cementite (Fe3C), the only 

well-known iron carbide, is not decomposed by pure water or by sea 

water at 150°. It is nearly certain, however, that there are several 

iron carbides, and Moissan does not appear to have tried steam at 

higher temperatures.

Even the existence of the natural, terrestrial carbides of iron demanded by Mendeleef's hypothesis has been questioned, but it will 

be shown a little later that this objection at least is not well taken.

Thafc carbon irons digested with acids evolve hydrocarbons was 

first shown by J. L. Proust d more than a hundred years ago. He 

experimented, both on cast iron and on iron sponge reduced at a 

relatively low temperature in glass. The most elaborate investigation 

is by Stanislas Cloez. c He produced a long series of Irydrocarbons. 

from cast iron by solution in chlorhydric and sulphuric acids. From 

specular iron (which contains much manganese) he was also able to

0 Bull. Soc. imp. nat. Moscon, new ser., vol. 3, 1800, p. 720.

6 Ber. Deutsch. chem. Gesell., vol. 10, 1877. p. 229. This is a report, of a meeting of 

the Russian Chemical Society, where Mendeleef made his views known in January, 1877. 

See also Mendeleef's Principles of Chemistry, vol. 1, 1005, p. 402.

0 Trait6 de chimie, vol. 2, 1005; p. 374.

<l Nicholson's .Tour. Nat. Phil. Chem., etc., vol. 5, 1803, p. 100, quoting from Jour, de 

physique, ed. by de Lametherie, vol. 56, 1802, p. 276.

 Compt. Rend., Paris, vol. 78, 1874, p. 1565 ; vol. 85,1S77, p. 1003; vol. 86,1878, p. 1248.
AND GENESIS OF PETROLEUM. 17

evolve hydrocarbons by the action of water at a low red heat, and 

from ferroinanganese by water at only 100°. Mendeleef, too, made 

from manganiferous pig iron, by the action of chlorhydric acid, a 

mixture of hydrocarbons indistinguishable from naphtha. Of course 

this is interesting and important, but native irons seem to contain 

the merest traces of manganese.

As is well knoAvn, Moissan ° produced in the electric furnace and 

studied in some detail a long series of metallic carbides. The carbides 

of the metals of the alkalies and the alkaline earths when brought 

into contact with water yield acetylene which has not been found in 

petroleum. The carbide of aluminum gives methane and that of 

manganese equal volumes of methane and hydrogen, whereas the carbides of iron, nickel, and cobalt in water do not emit hydrocarbons 

at ordinary temperatures. Moissan l was led by this investigation to 

believe that carbides, other than those of iron, exist in the interior of 

the earth and that their decomposition by water yields a part of the 

petroleum. (The bituminous schists of Autun, on the other hand, he 

thought organic.)

This hypothesis has much to recommend it. That temperatures of 

well over 2,000° exist within the earth I think almost certain, because 

the temperature of the earth at its consolidation must have approximated to a condition of convective equilibrium. There seems no 

known reason Avhy carbides besides those of iron might not have 

formed in the earth, especially those of aluminium and manganese. 

None have been found as yet, however. Possibly they may exist in a 

state of solid solution, and thus have escaped recognition. Until 

they are recognized, Moissan's theory is only plausible.

It is a n^stcry to me why Mendeleef and Moissan should have 

relied for the decomposition of their carbides on water alone. Volcanic eruptions are regularly accompanied by the emission of vast 

quantities of ammonium chloride and free chlorhydric acid. According to Mr. Suess, the amount of free chlorhydric acid is sometimes 

so .great that volcanic rains seriously injure vegetation over wide 

areas. Again, ammonium chloride splits up into ammonia and free 

chlorhydric acid at a temperature approaching 350° under atmospheric pressure. Visible red heat begins ne.ar 500°, so that except in 

the cooler parts of a volcano none of the chlorhydric acid near the 

surface is neutralized by ammonia. Even in solution ammonium 

chloride may be partially dissociated, ammonia escaping and leaving 

a certain amount of free chlorhydric acid. Hence it Avould seem that 

volcanic waters would in most cases be acid and competent to evolve 

hydrocarbons from iron carbides.

"Trait£ tic chimie, vol. 2, 1905, p. 259.

"Proc. Roy. Soc., London, vol. 60, .1890-97, p. .156.
18 LOCAL MAGNETIC DISTURBANCES

Water, however, is not essential to the formation of hydrocarbons 

from carbides even as a solvent for acids. Mr. Brim 0 reports his 

results on this subject in the following terms:

The chemical reactions in volcanoes proceed without the cooperation of 

water; this the writer has confirmed anew from observations on Pico de Teyde 

and Timanfaya, in the Canaries. In discussing the formation of hydrocarbons 

(which are very common in volcanic ash.) it is evident that the reactions between carbides and ammonium chloride, always present in abundance, must be 

taken into consideration. Salvador! l produced methylamine and acetylene 

from calcium carbide and ammonium chloride; and the writer observed during 

the same reaction the appearance of fluorescing hydrocarbons resembling crude 

petroleum. With iron carbide a paraffin-like substance was obtained, accompanied by gaseous hydrocarbons and free hydrogen. With aluminium carbide 

methane and hydrogen were evolved.

Artificial irons differ so considerably from the native metal that it 

seemed very desirable to test the action of dry ammonium chloride on 

Greenland iron. Mr. G. P. Merrill was good enough to supply me 

with a few grams from a specimen of an Ovifak iron, which is about 

as hard as the best tool steel, but very brittle, and which contains a 

large amount of combined carbon. The powdered metal was heated 

with pure ammonium chloride in an atmosphere of nitrogen. Of 

the educts a small portion condensed at zero degrees to a pasty grease, 

somewhat thicker than vaseline; a second portion, not condensible in 

ice water, was absorbed by bromine water, which was bleached as the 

absorption progressed. The gases escaping from the bromine water, 

after being freed from bromine, were passed over hot copper oxide 

and the carbon dioxide formed was caught as barium carbonate. 

Both saturated and unsaturated hydrocarbons were thus present in 

the educts. The gases which passed the bromine water will burn in 

air almost without luminosity and must consist mainly of hydrogen 

and methane. More of the carbon seems to be represented by the 

saturated volatile hydrocarbons than by the condensible oils or the 

bromine compounds, and the pasty grease therefore probably contains 

paraffin. The unsaturated hydrocarbons are perhaps due to the 

cracking of paraffins. I see no reason to doubt that cracking may 

occur in some solfataric oil deposits and that marked differences in 

the composition of oils from different pools may be thus accounted 

for. The combined carbon of the iron appears to be completely converted into hydrocarbons, for there is an approximate quantitative 

relation, and no graphite was detected in the residues from the metal. 

A brownish-gray, nonmagnetic powder remains behind which probably consists of iron nitrides.0 Large quantities of nearly colorless 

crystals of ferrous chloride also form.

«Chem. Zeitung, vol. 32, 1908, p. 302. 

6 Gazz. chim. ital., vol. 32, 1902, p. 496.

c Either metallic iron or ferrous chloride heated in an atmosphere of ammonia yields 

silvestrite or other iron nitrides; Hintze, Handbuch der Mlneralogle, vol. 1, 1898, p. 189.
AND GENESIS OF PETROLEUM. 19

These experiments were made for mo by Mr. George Steiger, who 

will publish when completed "such quantitative determinations as the 

amount of material available enables him to make. In the meantime 

it is established that solid, liquid, and gaseous hydrocarbons are copiously evolved by the action of dry ammonium chloride on native iron. 

There seems no reason to suppose that pressure would interfere with 

this evolution. It follows that the formation of hydrocarbons from 

inorganic substances may very probably take place at depths far 

greater than those to which vadose waters penetrate, far greater also 

than those at which stratified rocks are prevalent.

FACTS BEARING ON CARBIDE OF IRON THEOKY.

That iron carbides exist in artificial iron is well and definitely 

known. Cementite, Fe:! C, was first prepared in a pure state by Moissan ° in 1897, but seems to have been recognized as a distinct compound 

by Sir F. Abel in 1885. It is probable that several other carbides exist 

in smelted iron, but their study is attended by great difficulties.

Most modern metallographers accept, so far as its general features 

are concerned, Roozeboom's phase-rule diagram of iron constitution. 

As so represented, all uncombined carbon is graphite and the combined carbon is all combined in carbides. In respect to matters of 

detail, however, there are differences of opinion. It has been held 

by a number of metallographers that at ordinary temperatures the 

most stable mixture consists of ferrite (pure iron) and graphite; or, 

in other words, they believe that cementite tends to dissociate into 

graphitic carbon and ,iron. But two recent investigations by Mr. 

G. B. Upton 6 seem to disprove this view. He concludes that the 

most stable mixture consists of ferrite and Fe2C accompanied by no 

graphite unless carbon is present in excess of the proportion represented by this carbide. In a higher metastable phase, as everyone 

acknowledges, cementite exists; but by very slow cooling Fe;!C is 

resolved, according to Mr. Upton, into Fe2C and Fe. " Stead's 

brittleness " is referred to this change.

Among other confirmations of his views Mr. Upton cites the 

magnetic permeability of the soft, gray cast iron employed in the 

construction of electrical apparatus. He finds that this is only about 

half as great as it should be were the castings composed of graphite 

and magnetically " soft " ferrite.

In 1889 Mr. E. Weinschenck ° discovered in the Magura meteorite 

a compound to which he gave the name cohenite. Its formula is

"Traite" de chimic, vol. 4, .1005, p. 302.

".lour. Physical Chemistry, vol. 12, 1908, p. 507, and vol. 13, 1900, p. 388.

o Annalcn Naturh. Hofmus. Wien, vol. 4, 1880, p. 94. I flnd some erroneous references 

in the literature to cohenite as FeC3. The density of cohenite is 7.227. Moissan found 

the density of cementite 7.07.
20 LOCAL MAGNETIC DISTURBANCES .

(Fe,Ni,CO) :;C. This may be regarded as a cementite in which a 

part of the iron is replaced by nickel and cobalt, or cementite may be 

considered as a cohenite free from cobalt and nickel. Cohenite 

has since been identified in several meteorites and also in the terrestrial iron of Greenland at Ovifak and Niakornak, localities separated by about 100 miles.

The large amount of combined carbon in the Greenland iron has 

frequently been commented upon. Daubree,0 who found 3 per cent 

in one specimen from Ovifak, said: " The presence and abundance of 

carbon in these masses, combined carbon as well as that in a free 

state," is remarkable. J. Lawrence Smith & also found 2.34 per cent 

.combined carbon in iron extracted in small particles from the basalt 

of Ovifak. His comment is: " The very large percentage of carbon 

in a state of combination in the iron of Ovifak. without traces of 

graphite, is a very interesting fact and demands a special chemical 

investigation." Although there was no graphite in the iron, Smith 

noted its presence in the basalt. In the Niakornak iron he found 1.74 

per cent carbon, all combined. Mr. Carl Hintze c expresses his belief 

that the carbon of Smith's irons existed as cohenite.

In 1897 Emil Cohen d discovered that although Greenland irons 

disintegrate with great rapidity, the decomposition is not complete. 

In fact, unattacked metallic grains remain, and these can be practically freed from extraneous matter. Parcels of such grains, both 

from Ovifak and Niakornak, were analyzed for him by Mr. Sjostrom 

and their composition found to correspond very satisfactorily to 

cohenite.6

This identification seems to me of great importance. Not only 

do the Greenland irons contain carbides, but cohenite must be stable 

at ordinary temperatures. The Greenland basalts unquestionably 

took decades to cool from the temperature of fusion, say 1,100° or 

1,200°, to that of the atmosphere. No experimenter can hope ever 

to attain so gradual a cooling, and since the iron reached atmospheric 

temperatures it has had thousands of years to complete molecular 

readjustment. Cohen concluded that chalypite, or Fe,C, does not. 

exist in the Greenland irons. These facts, however, are not, to my 

thinking, necessarily inconsistent with Mr. Upton's conclusions. The 

nickel may make all the difference, and perhaps, some of the good 

qualities of nickel steel ate due to the stability of cohenite under 

conditions such that cementite would split up.

a Compt. Rend., Paris, vol. 74, 1872, p. 1542. 

" Annales chim. phys., 5th ser., vol. 16, 1879, p. 452. 

o Handbuch der Mineralogie, vol. 1, 1898, p. 190. 

* Meteoritenkunde, heft 2, 1903, p. 226.

6 Cohen remarks that these Greenland cohenites are identical with meteoric cohenite 

in their behavior to acid and neutral solutions as well as in composition.
AND GENESIS OF PETKOLEUM. 21

For the present purpose the vital point is that all investigations 

of the Greenland terrestrial irons show the presence of iron carbides 

in abundance.

Mendeleef, in supporting his hypothesis, expressed his belief that 

the nucleus of the earth is composed of metallic iron, and it was 

from the action of water on this nucleus that he derived his hydrocarbons. The idea of an iron nucleus, long familiar, has grown in 

favor during the last half century. It is probable, indeed, that with 

such internal densities as are implied by the known mean density 

and surface density of the globe, stability would be impossible unless 

the intrinsic density of the nucleus were great. On the other hand, 

this nucleus, the barysphere, must lie far below the surface, several 

hundred miles assuredly, possibly a thousand; and it is improbable 

that surface influences of any kind are sensible at any such depths. 

Vadose water in particular is confined to an extremely superficial, 

shell.

These considerations, however, involve only a very slight modification of the iron-carbide theory. If the earth, like meteorites, consists 

of metallic iron and rock, the rock must overlie the iron as slag does in 

a blast furnace, and it may be taken for granted that this slag contains 

" shot metal," that this rock contains entangled metallic particles 

which presented so much surface per unit volume as to prevent their 

sinking to the bottom of the viscid, lithoid magma. Such " particles," 

too, might have considerable dimensions and even weigh tons, since 

no provision was made in the world-building process for mobile slags 

and clean separation. It is thus rather to clouds of iron particles 

suspended in the lithoid shell of the globe than to an iron nucleus 

that advocates of the carbide of iron hypothesis of petroleum must 

appeal.

Native terrestrial iron or nickel iron has been found in many parts 

of the world, but nowhere in such abundance or in masses of such size 

as at Disco Island and the neighboring mainland of Greenland. 

Long before Nordenskiold discovered this wonderful locality, Andrews had found specks of iron in the basalt of Antrim, Ireland. 

Irons supposed to be terrestrial have since been detected in every 

quarter of the globe, and though a meteoric origin is suspected for 

some of them, many are beyond question natives of this planet. At 

some points again a reduction by burning seams of coal or lignite is 

probable, but there are also many undoubted instances in which the 

metal is a component of a massive rock. Curiously enough, however, 

the native metals in which nickel predominates carry no appreciable 

amount of carbon. So far as carbides are. concerned, therefore, 

awariiite, josephinite, and souesite must be ruled out, for all of them 

contain from 60 to 75 per cent of nickel.
22 LOCAL MAGNETIC DISTUKBANCES

In the United States native iron was first discovered by G. H. 

Cook a in New Jersey. " Native iron," he reported, " could be obtained from any of the specimens we had from the various ridges of 

trap in the red sandstone region of New Jersey." This iron evolved 

hydrogen with acids and precipitated copper from acid sulphate solution. In 1877 G. W. Hawes & found native iron embedded in mag- O

netite in New Hampshire, and reported that he had also detected it in 

the fresh trap rocks of the Connecticut River.

In 1898 Mr. F. L. Ransome examined for me a series of several 

hundred thin sections of subsilicic rocks from various parts of the 

country, with a view to detecting metallic iron. The sections were 

uncovered, cleaned, and immersed in copper sulphate solution. It 

was found difficult to distinguish very minute particles of metallic 

copper from ferric oxide under the microscope, even in direct sunlight. 

After all doubtful cases had been rejected, only six sharply determinable occurrences from the United States remained. Of these four 

were olivine basalts from northern California, one a saxonite from 

Riddles. Oregon, and one a peridotite from Elliot County, Kentucky.0 Had we been able to dispose of hand specimens by crushing 

them and extracting the magnetic particles, it is presumable that more 

localities would have been detected.

IRREGULAR COMPASS DECLINATION IN PETROLEUM

FIELDS.

In the foregoing pages the condition of knowledge with reference 

to the origin of petroleum and other bituminous substances has been 

reviewed. The result is thoroughly unsatisfactory. Some oils are 

undoubtedly organic and some are beyond question inorganic. The 

evidence shows that neither variety can properly be regarded as unimportant. This review, however, does not elucidate the source of 

the principal deposits, the great petroleum pools. They may have 

been derived from carbonaceous matter of vegetable or animal origin, 

and they may have been derived from carbides of iron or other metals. 

It is also barely possible that the hydrocarbons exist as such in the 

mass of the earth.

In thinking over this situation it occurred to me to inquire whether 

any relation could be detected between the behavior of the compass 

needle and the distribution of hydrocarbons. Not very much could 

be expected from a comparison of these phenomena, for magnetite

a Ann. Rep. New Jersey Geol. Survey, 1874, p. 56.

"Am. Jour. Sci., 3d s-r., vol. 13, 1877, p. 33.

"The basalts are (1) No. 369 Ps., H. W. Turner collection, Downieville quadrangle, 2.8 

miles west by south from Mount Jackson; (2) No. 909 S. N., H. W. Turner collection, fragment from basaltic Tuscan tuff, Chico quadrangle, 4 miles a little east of south from 

Inskip ; (3) No. 1789 C. R., .T. S. Diller collection, 1.5 miles southwest of Lassen Teak; 

(4) No. 1168 M. S., J. S. Diller collection, 18 miles north of Mount Shasta, in Siskiyou 

County. The saxonite and peridotite have both been described by Mr. Diller.
U. S. GEOLOGICAL SURVEY 

GEORGE OTIS SMITH, DIRECTOR BULLETIN 401 PLATE I

127 125 123 121° 119° 117° 115° 113° 111° 109° 107° 105 103 101° 99 97° 95° 93° 91° 89° 87° 86° 83 81 77° 75° 73° 71

The locations of the Petroleum Deposits are furnished by Datttd T. Day of this Surfey. The lines of 

Magnetic Declination are taken from the map by A, L. 

Batter in U. S. Magnetic Tables and Magnetic Charts 

for 1905 issued by the Coast and Geodetic Sufoey.

117° 115° 113' 111 77° 75 73

PETROLEUM DEPOSITS AND LINES OF EQUAL MAGNETIC DECLINATION FOR 1905
AND GENESIS OF PETROLEUM. 23

exerts an attraction on the needle whether this ore occurs in solid 

masses or is disseminated in massive rocks; and again, as was first 

shown by Messrs. Brimhes and David," many if not all volcanic rocks 

possess polarity, so that repulsions are involved as well as attractions. 

Even if the iron carbide theory of genesis were known to be correct, 

and exclusively correct, no one would think of maintaining that all 

bodies of magnetite have a connection, however remote, with the 

occurrence of petroleum. Hence any indications of iron carbides and 

associated petroleum which the compass might be supposed to afford 

would, be obscured by the local attraction of independent masses of 

magnetite. Earth currents are also to some extent local and thus O

produce irregularities in declination.

Nevertheless, on glancing at Mr. Bauer's map of the magnetic 

declination 6 in the United States for January 1, 1905, with this idea 

in mind, I saw that the irregularities of the curves of equal declination were strongly marked in the principal oil regions. When this 

map was compared with one prepared by Mr. David T. Day c showing in detail the known hydrocarbon deposits of the United States 

the coincidences recognized became more striking and other agreements became evident.

The chart accompanying this paper is merely a compilation from 

the two maps of Messrs. Bauer and Day. The red lines are the isogonal loci, and the black dots or blots represent deposits of hydrocarbons. The most marked agreement is found throughout the great 

Appalachian oil field, which is the area of greatest variation in declination. In California, also, strong deflections of the isogonal lines 

accompany the chain of hydrocarbon deposits. In the interior of 

the country the coincidences are less marked, but they are very noticeable, as may be seen by inspection of the map.

There are other systematic irregularities, wrinkles in the isogonic 

topography as I may call them, which can not be connected with oil. 

One such wrinkle runs down the Atlantic coast and contains the 

New Jersey native iron as well as known deposits of magnetite. 

Another lies near latitude 47° and is doubtless due to the great 

northern iron belt.

No detailed chart of the magnetic declination in the petroleum 

fields of the Caucasus has yet been prepared. Mr. Bauer informs 

me, however, that great magnetic disturbances exist in that region, 

so that relations not dissimilar to those in this country are probable.

« Compt. Rend., Paris, vol. 133, 1901, p. 155.

6 A line of equal declination, also called an " isogonal line," is one along which the compass needle everywhere makes a particular angle with the geographical meridian. A magnetic meridian differs in toto from an isogonal line. The map referred to appeared in U. S. 

Coast and Geodetic Survey magnetic tables and magnetic charts for 1005, chart 1.

« Mr. Day was kind enough to place this map in manuscript at my disposal. It will 

appear in Mineral Resources U, S. for 1008, U. S. Geol. Survey, 1900,
24 LOCAL MAGNETIC DISTUBBANCES AND GENESIS OF PETKOLETJM.

Study of the map accompanying this paper justifies the statement 

that the coincidences between the occurrence of petroleum and local 

disturbances of the compass needle are too numerous to be attributable to mere accident or chance. There must therefore be a direct 

or an indirect historical connection betAveen the two phenomena in 

the regions of coincidence.

CONCLUSIONS.

None of the hypotheses of petroleum genesis is proved by the relations shown on the map. These relations, however, are compatible 

with the supposition that the great oil deposits are generated from 

iron carbides either by or without the agency of water. Of these 

alternatives the latter is the more plausible.

What the map does prove is that petroleum is intimately associated 

with magnetic disturbances similar to those arising from the neighborhood of minerals possessing sensible magnetic attraction, i. e., 

iron, nickel, cobalt, or magnetite. Henceforth no geological theoiy 

of petroleum will be acceptable which does not explain this association.

No one doubts the vast industrial importance as well as the deep 

geological interest of the petroleum question. As time elapses it will 

grow more and more important, for the pinch of dwindling coal 

resources will probably affect children of those already born. In the 

interest both of the development and the conservation of our natural 

resources all the means at the command of science should be. brought 

to bear on this mysterious subject. A geologist and a chemist each 

of the highest order should be coupled in the long and difficult investigations needed to elucidate the genesis of petroleum. The expense 

would be considerable but the economy would be enormous.

0