ORIGIN OF THE BOGHEAD COALS. 

BY REINHARDT THIESSEN. 

The bituminous rocks of sedimentary origin matter is considerably more abundant than 

may be classified ro.ughly under two main the mineral matter is generally called cannel 

heads-coals and bituminous shales. In a coal. 

strict sense no definite line can be drawn be- Under bituminous shales, therefore, are here 

tween these two groups, because coals may considered all bituminous rocks usually desiginsensibly grade into bituminous shales. nated cannel coals, boghead coals, oil shales, 

Chemically the boghead coals are preeminently ·torbanite, tasmanite, and cannel "slates." 

bituminous. These rocks have never been classified satisCOAL. 

Coal is composed in the main of the residues 

of the components of plants. The residues of 

the ligno-cellulosic components-that . is, the 

woody portions-form the larger part. With 

these are always associated in varying amounts 

the residues of the more resistant components 

and products of plants, of which the resins, 

resin waxes, fats, and oils or their derivatives 

are the most abundant. Besides these, many 

other resistant plant products, too many to 

enumerate, enter into the formation of coal. 

The mineral content of coal is relatively low. 

BITUMINOUS SHALE. 

A shale is generally defined as a rock formed 

by the consolidation of clay mud or silt, having 

a finely stratified, laminated, or fissile structure. Some sand is usually mingled with the 

silt. If such a rock contains organic matter 

and is dark colored it is termed carbonaceous 

shale; if the organic matter is of a bituminous 

nature (highly hydrogenous) the rock is called 

bituminous shale; and if the rock is rich enough 

in bituminous substances to yield oil and gas 

in relatively large amounts on distillation it 

is called oil shale. The mineral matter in 

bituminous shales may vary greatly; in oil 

shales the organic matter is generally less than 

the mineral matter. Rock in which the mineral 

and organic matter are approximately in equal 

proportions may be called cannel slate or 

cannel shale; and rock in which the organic 

factorily in accordance with their genetic 

characters; it is impossible to classify them 

definitely according to their general appearance 

and physical properties. However, they may 

be classified definitely and specifically into 

several well-defined groups, according to their 

origin or the origin of their predominant constituent or constituents. 

The chief components of organic shale are 

humic matter-that is, ligno-cellulosic and 

other matter formed by the degradation of 

carbohydrates-resinous matter, spore matter, 

cuticular and other eerie matter, and oil-algal 

matter. It contains also small amounts of 

certain other components of unknown origin. 

According to their origin, therefore, the 

bituminous sedimentary deposits may be 

classed as (1) humic, if the predominant 

organic constituent is matter derived from the 

degradation of carbohydrates-that is, such 

substances as wood, cellulose, lignin, bark, or 

suberin, gums, mucilage, and starch; (2) spore, 

if the predominant organic matter is derived 

from spores; (3) eerie or waxy, if the predominant organic matter is derived from the 

waxy substances of plants, including oil or fat; 

(4) resinous, if the predominant organic matter 

is derived from the natural resins of plants; 

(5) algal, if the predominant organic matter is 

derived from oleaceous algae, as in the boghead 

coals. 

Each of these substances is invariably 

admixed with one or more of the others 1n 

121 
122 SHORT'ER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923-1924. 

different proportions. Usually one predominates, but two or even three components may 

be present in equal or about equal proportions, 

with others in less amounts. 

THE BOGHEAD COALS. 

Boghead coals differ little from any other 

bituminous shales in outward appearance, and 

it is often difficult if not impossible to distinguish them. They are close grained, brownish 

black to black, very tough, elastic, and difficult 

to break; usually they break with a conchoidal 

or subconchoidal fracture. In mass they show 

definite layering, but they will rarely split along 

definite horizon tal planes. 

When examined under the microscope in thin 

sections boghead coals are at once found to 

differ from all other bituminous shales in that 

they contain or are composed largely of peculiar irregular oval yellow bodies, through the 

structure and composition of which they are 

easily distinguishable from all other bituminous 

rocks. 

Other names have been applied to these deposits, such as kerosene shales, torbanite, torbanehill mineral, brown cannel coal, bathvillite, 

algal coal, albertite, bituminite, parrot coal, and 

cannel coal. But as the term "boghead coal" 

has been most often used, has in general been 

so consistently applied to deposits of this type 

and is so thoroughly incorporated into the literature, it can not well be discontinued, although it is not satisfactory. It is used in 

this paper for want of a better name. 

NOMENCLATURE. 

The term "boghead" was first applied to 

coal of this variety found on the Boghead estate, near Bathgate, Linlithgow, Scotland. At 

Torbane Hill, also near Bathgate, it was called 

'' torbanehill mineral'' and ''torbanite.'' 

"Kerosene shale" 1 was first applied to boghead coals by the oil-shale industries of Mount 

Kembla, near Wollongong, New South Wales, 

Australia, and became identified with the industries at other localities and in other countries. The term is still used in Australia. 

"Kerosene coal" is a term used by J. R. M. 

Robertson,2 of Scotland. 

I Carne, J. E., The kerosene-shale deposits of New South Wales: New 

South Wales Geol. Survey Mem., Geol. No.3, Dept. Mines and Agr., 

19<13. 

2 Robertson, J. R. M., Min. Inst. Scotland Trans., vol. 14, pt. l), pp. 

88-112, 1892. 

"Wollongite" was proposed by B. Silliman 3 

for the substance found at Hartley, New South 

Wales. 

''Petroleum-oil cannel coal" is a term applied by John Mackenzie 4 to the Australian 

deposits. 

"Bituminite" is a name proposed for tor .. 

bani te by T. S. Traill. 5 

"Parrot coal" is a Scotch terni arising from 

the crackling noise produced when torbanite is 

placed in the fire. 

"Cannel coal," a corruption of ''candle 

coal," was first applied to torbanite because of 

its property of burning with a clear flame, like 

a candle, and later became a synonym of torbanite and boghead. The term was soon applied to all coals of similar texture and appearance and so became a generic instead of specific term. 

''Brown cannel" was later used by W. B. 

Clarke 6 to distinguish a boghead fro:m ordinary cannel coal. 

"Algal coal" was applied to the boghead 

coals by Bertrand and Renault.7 

DISCOVERY AND EARLY msTORY. 

Torbanite was discovered at Torbane Hill, 

Linlithgowshire, Scotland, in 1850, and later 

was found at Boghead, Bathville, Inchroos, 

and Cappers, all near Bathgate, in Linlithgowshire. It was soon found to be a substance 

exceedingly rich in oily constituents and on 

this account was brought into special industrial prominence both in Europe and in America. It was about this time that, the patents of 

Dr . .Albert Gesner 8 having been sold to the 

North American Kerosene Gas Light Co., kerosene was manufactured from coal and introduced generally to the American public. This 

kerosene or "coal oil" was objectionable on 

account ·of its unpleasant odor, and therefore 

large quantities of torbanite were shipped to 

America for the manufacture of kerosene that 

would not have the odor. This led to litigation over patent rights both in America and in 

England. In England the oil made from tora Silliman, B., Am. Jour. Sci., 2d ser., vol. 48, p. 85, 1869. 

• Mackenzie, John, Mineral production of New South Wales, 1887; 

New South Wales Dept. Mines and A~r., Annual report for 1887. 

6 Traill, T : S., Roy. Soc. Edinburgh Trans., vol. 21, pp. 7-13, 1857. 

6 Clarke, W. B., Geol. Soc. London Quart. Jour., vol. 22, p. 446, 

1866, and elsewhere. · 

7 See footnote 18, p. 124. 

s Gesner, G. W. (son of Albert Gesner), A practical treatise Jn coal,. 

petroleum, and other distilled oils, 1865. 
ORIGIN OF THE BOGHEAD COALS. 123 

banite was called "paraffin oil" and was used 

in "mineral-oil lamps." The litigation over 

the patent rights led to the institution of a 

lawsuit that became famous-that of Gillespie 

v. Russel. The dispute concerned the question whether torbanite was coal or not coal 

and affected the ownership of the deposits. A 

large number of scientific men in Europe were 

brought before the court to decide whether the 

so-called boghead coal is coal or bituminous 

clay, and the suit incidentally led to the study 

of the origin of this substance. 

Quecket 9 maintained that torbanehill min_ 

eral is not a coal; that it is not like any of the 

combustible substances used in Great Britain 

as coal; that, although possessing some of the 

properties of coal, it is nevertheless a mineral 

having a basis of clay which is strongly impregnated with a peculiar combustible substance; and that any plants found in it are 

accidental and have no more been concerned 

in the formation of the mineral than a fossil 

bone in that of the rocks in which it may be 

embedded. 

Bennett's opinion 10 was that the torbanehill mineral, although it presents essentially 

no trace of vegetable structure, is rich in bituminoid substances-a circumstance explained 

by the fact that it is found in the neighborhood of coal, so that the bituminoid or resinoid 

matter formed in the partly woody structure 

of the coal has flowed out, mixed itself with, 

and solidified in the essentially earthy substance of the torbanehill mineral. 

Balfour 11 maintained that torbanite was of 

the same class as black cannel coal. 

OTHER EARLY WORK ON BOGHEAD COALS. 

Redfern, 12 lecturer in anatomy, physiology, 

and histology in the University of Aberdeen, 

·supported the plant origin of the torbanehill 

mineral and argued that it is like all other 

9 Quecket, John, On the minute structure of a peculiar combustible 

mineral from the coal measures of Torbane Hill, near Bathgate, Linlithgowshire, Scotland, known in commerce as Boghead cannel coal: 

Micr. Soc. London Trans., vol. 2, pp. 34-36, 1853. 

10 Bennett, J. H., An investigation into the structure of torbanehill 

mineral and of various kinds of coal: Roy. Soc. Edinburgh Trans., 

vol. 21, pp. 173-185, pls. 1-2, 1857. 

u Balfour, J. H., On certain vegetable organisms found in and from 

Fordel: Roy. Soc. Edinburgh Trans., vol. 21, pp. 187-193, 1854. 

12 Redfern, P ., On the nature of torbanehill and other varieties of 

coal: Micr. Soc. Quart. Jour., 1855, pp. 106-127. 

cannel coals. Speaking of the yellow bodies 

of which the mineral is largely composed, he 

said that he knew of no other interpretation 

except that they are produced by free vegetable cells, such as spores or pollen grains, yet 

he could not confidently affirm that they are 

such; but whatever they may be, they are 

always to be found in other cannel coals. 

The kerosene shale in Australia was discovered long before that in Scotland. Probably 

the earliest reference to it was published in 

Paris in 1807, after .the return of a French 

scientific expedition that visited Australia in 

1802. It was not utilized, however, until1865. 

David/3 a professor in the University of Sydney, New South Wales, was the first to investigate the kerosene shale of Australia by 

the most advanced methods of research and 

the first to propound the hypothesis that this 

shale is of fresh-water algal origin. The first 

scientist, however, to suggest the algal origin 

of the very richly bituminous shales was T. S. 

Ralph,14 who claimed that the organic matters 

forming tasmanite were algae; but in this he 

was incorrect, as tasmanite is described as a 

spore cannel coal. 15 

Clarke 16 thought that kerosene shale unquestionably resulted from local deposits of 

resinous wood and passed gradually into ordinary coal. Dixon 17 argued that the idea of 

resinous origin must be abandoned, as the 

resins yield aromatic products and not paraffins. He also thought it more probable that 

the shales came from oil-producing or waxproducing plants, most likely the latter, in 

view of the considerable yield of solid paraffins from the shales. 

The algal theory of the origin of the boghead 

coals was most prominently developed by 

Renault and Bertrand, and the result of their 

investigations ranging over 25 years was 

1a David, T. W. E., Note on the origin of kerosene shale: Linnean 

Soc. New South Wales Proc., 2d ser., vol. 4, pp. 483-500, 1889. 

u Ralph, T. S., Royal Soc. Victoria Trans., 1865, p. 4; cited by Came, 

J. E., The kerosene-shale deposits of New South Wales; New South 

Wales Geol. Survey Mem., Geol. No. 3,.p. 61, 1903. 

16 Newton, E. T., On tasmanite and Australian white coal: Geol. 

Mag., vol. 2, pp. 337-342, 1875; New South Wales Dept. Mines Ann. 

Rept. 1879, p. 33. 

16 Clarke, W. B., Industrial progress of New South Wales, 1871, p. 

449; cited by Carne, J. E., op. cit., pp. 59-61. 

11 Dixon, W. A., Australasian Assoc. Adv. Sci. Proc., vo. 1, p. 134, 

1887; cited by Carne, J. E., op. cit., p. 61. 
124 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923-1924. 

summed up by Renault. 18 A fundamental 

jelly, a sort of gelatinous precipitate, supposed 

to have existed in the ancient lakes, pools, 

and swamps, is one of the chief assumptions 

in their theory. In this jelly were suspended 

spores, pollen grains, plant cells, cuticles, and 

minute vegetable debris, but paramount were 

certain gelosic algae surrounded by a gelatinous 

sheath or matrix, something like the Nostoc 

of to-day. Besides these, certain secretive 

cells are supposed to have been held in suspension, still presenting in detail their protoplasmic and nuclear contents. The fundamental jelly is supposed to have been produced by the action of microorganisms upon 

the organic matter, possibly upon the algae 

themselves. It is the essential part of all 

coals, and the algae, spores, pollen grains, and 

other minute bodies are merely accidental; 

one or another of these nonessential constituents may predominate, thus determining the 

particular character of the coal. 

A careful distinction is therefore drawn by 

these two investigators between boghead and 

cannel coals. In the boghead coals the 

suspended matter consists chiefly of gelosic 

algae; in the cannel coals it consists of spores. 

Between the two are found all grades of 

mixtures, and there may be boghead cannel 

coals where the algae are more abundant than 

the spores and cannel bogheads where the 

spores are more. abundant than the algae. 

The size of the yellow bodies composing the 

boghead coals is only a little smaller than it 

must have been when living. As the mass in 

the known living gelosic algae contains only a 

small percentage of solid matter, the remainder 

being water, it seems clear that such algae 

could not form the mass of the yellow bodies 

as found in the bogheads. In order to account 

for this discrepancy, the algae are supposed to 

18 Renault, B., Surquelquesmicroorganismes des combustibles fossiles. 

Soc. ind. min. St.-Etienne Bull., 3d ser., vol. 13, pp. 895-1191, 1899; 

vol. 14, 456 p., 66 fig>., 30 pis., 1900. 

See also Bertrand, C. E., Le boghead d' Autun: Soc. ind. min. Bull., 

vol. 6, pp. 453-506, 1892; Bertrand, C. E., and Renault, B., Pila bibractensis et le boghead d' Autun: Soc. hist. nat. Autun Bull., vol. 5, pp. 

159-253, 1892; Bertrand, C. E., and Renault, B., Reinschia australis et 

premieres remarques sur la kerosene shale de la Nouvelle-Galles du 

Sud: Soc. hist. nat. Autun Bull., vol. 6, pp. 321-425, 1893; Bertrand, 

C. E., Nouvelles remarques sur le kerosene shale de la Nouvelle-Ganes 

du Sud: Soc. hist. nat. Autun Bull., vol. 9; pp. 193-292, 1896; Bertrand, 

C. E., Conclusions gi'merales sur les charbons humiques et les charbons 

de purins: Compt. Rend., vol. 127, pp. 822-825, 1898; Bertrand, C. E., 

Description d'un echantillon de kerosenli\ shale de Megalong Valley, 

N. S W.: Linnean Soc. New South Wales Proc., vol. 25, pp. 617-£49, 

1901. 

have had a great affinity for bituminous 

substances and to have been impregnated 

with and enriched by them to the extent of 

the present volume. No satisfactory explanation is offered for the origin of the bituminous 

matter, but probably it was produced by the 

decomposition of the algae themselves through 

bacterial activities. 

This theory was widely accepted at one 

time, although some refuted it, foremost 

among whom was Jeffrey,t9 who concluded 

from the study of numerous thin sections 

made from an abundance of material that the 

bodies interpreted as algae by Bertrand and 

Renault are not algae but the highly sculptured 

walls of the spores of cryptogams. When 

sufficiently thin sections of the bodies in question are cut tangentially through the sculptured 

spore coats the resemblance to certain algal 

structures is made very plain. Reconstructions made from serial sections were thought 

to afford additional evidence of the true spore 

nature of these bodies by their alveolar structure ·and triradiate markings and their occurrence ·in tetrads. With reference to the 

larger "supposed algae" Jeffrey does not make 

his case so satisfactory, presumably owing to 

the distorted condition in which they exist 

and the difficulty of interpreting thin sections 

of a larger size. · But he presents the apparently 

reasonable argument that if those which are 

best preserved and by reason of their size are 

most easily studied in thin sections of coal 

prove not to be of algal affinities, a similar 

conclusion must be applied to the remaining 

organisms, which either by their large size or 

their imperfect condition of preservation can 

not be satisfactorily subjected to microscopic 

investigation. 

At first Zalessky 20 supported Jeffrey's opinion, which he thought was confirmed by examination of a preparation of a siliceous nodule 

found in the boghead of Autun. The alga, 

Pila bibractensis, seemed to him to be a spore 

with a reticular sculptured surface, and the 

walls of the supposed cells seemed to have the 

form of ribs jutting out on the surface of_ the 

19 Jeffrey, E. C., The nature of some supposed algal coals: Am. Acad. 

Arts and Sci. Proc., vol. 46, pp. 273-290, pl. 1-5, 1910. 

20 Zalessky,.M. D., On the nature of the yellow bodies of boghead, 

and on sapropel of the Ala-Kool Gulf of the Lake Balkash: Com. geol. 

Bull., vol. 33, pp. 495-507, Petrograd, 1914; Flore gondvanienne du bassin, 

de la Petchora, I, Riviere Adzva: Soc. ouralienne amis sci. nat. Bull, 

vol. 33, HH3. 
ORJGIN OF THE BOGHEAD COALS. 125 

spores. Studies of material sent to him later that of the blue-green algae of the genus Gloeoby Bertrand and Combray changed his opinion capsa, and Zalessky therefore proposed the 

to one in support of Renault and Bertrand's name Gloeocapsamorpha prisca for them. 

algal theory. In preparations of these siliceous Conacher 24 examined the oil shale and 

boghead samples he clearly observed the eel- torbanite of England and Scotland and conlular Pila structure, as if occurring in a more eluded that they are derived from the same 

or less natural state in the bog, giving good substances as coal but that in the shale there 

evidence to accept that these cellular bodies has been a much larger elimination of the 

are algae. woody matter, leaving a large proportion of 

As illustrating the nature and origin of bog- resinous matter mixed with sand. 

head coal Zalessky offers an example from the In 1914 the present writer 25 maintained that 

plant world of to-day in an alga, which he calls no algae were found in any of the boghead coals 

Botryococcus braunii,21 growing in the.brackish, he investigated, although many of the bodies 

shallow Ala-Kool Gulf, overgrown With ma~sh called algae by various investigators were found. 

and aquatic plants, at the southern extremity Many of these, however, were shown to be 

of Lake Balkash, in Turkestan. . This alga, spores; others were of unknown origin. Some 

bearing a considerable amount of ml, comes to of Renault's illustrations of Reinschia, showing 

the surface of the water. Zalessky states that both cross and horizontal sections, were cerwhen these algae accumulate on the shore, a tainly those of spore exines. The weakest 

hydrogen sulphide fermentation takes place; points in Renault and Bertrand's algal theory, 

and finally, when in contact with the air, they however, were those clauses relating to the 

dry and change from a dark-green into a yellow- "fundamental jelly" and the "bituminous 

brown elastic, rubber-like mass, which can be affinity" of the algae. No algae having the 

easily cut with a knife. Thin sections of this structure revealed by the yellow bodies in the 

mass sometimes clearly show the struct~re ?f boghead coals were known to the writer, n?r 

the algae, which much resemble ~he bodies In any that had as massive a cell wall as those In 

the siliceous boghead sample exammed. From the bogheads indicated. Ordinary living algae, 

this observation deductions are made as to the as well as those in the ancient swamps referred 

origin of the bogheads. A further study of to as being analogous, contain at the most only 

the habit~ of the algae and their transformation a small quantity of solid matter, by far the 

into the elastic mass had not been made. largest part of their mass being composed of 

Similar condusions 22 are drawn from a study water. Also, the cell walls of ordinary algae 

of sapropelic substances found. at. the bottoi? are of pectic-cellulosic nature-that is, they 

of Lake Bioloe at Tver, Russia, In a deposit are carbohydrates, which are readily attacked 

9 meters thick, said to be composed of b.lue- by putrefying organisms and are quickly degreen algae, principally of the genera M~cro- composed under ordinary conditions. Any 

cystis, Aplanocapsa, Alphanatheca, Ghroococcu.s, algal bodies that might have been preserved in 

Gleotheca, Synechococcus; and of the green the coals would be represented by only an exalgae Scenedismus obliquus, S~ened smus biju- ceedingly thin residue. Renault and Bertrand 

gatus, and Pleurococcus vulgans. . . probably also realized this difficulty, and to 

Later Zalessky 23 found that the bituminous overcome it they propounded the hypothesis of 

rock of the "Lower Silurian" in Petrograd and bituminous affinity, through which the gelaEsthonia along the Baltic coast, called kuker- tinous cell walls of the algae were supposed to 

site, were similar in nature to the boghead have absorbed a certain amount of bituminous 

shales of Autun. The fossil organisms in substances to account for their solidity and 

these rocks have a structure very similar to relative ~assiveness as represented by the 

21 Zalessky, M.D., on the nature of Pila of the yellow bodies of bog- yellow bodies in the coals. The fundamental 

head and on sapropel of the Ala-Kool Gulf of the Lake Balkash: Com:. jelly in which these bodies were supposed to 

geol. Bull., vol. 33, pp. 495-507, Petrograd, 1914. Litinsky, L. L., have been suspended has never been observed Balchash-Sapropelite: Petroleum, vol. 17, pp. 437-440, 1921. 

22 Zalessky, M. D., Soc. paleont. Russie Annuaire, vol. 1, pp. 25-42, 

1916. 2~ Conacher, H. R., A study of oil shales and torbanites: Geol. Soc. 23 Zalessky, M. D., Sur le sapropelite de l'age silurien forme par une Glasgow Trans., vol. 16, pt. 2, pp. 164-192, 1917. 

algue cyanophycee: Soc. paleont. Russie Annuaire, vol. 1, pp. 25-42, 2s White, David, and Thiessen, Reinhardt, The origin of coal: U.S. 1916. Bur. Mines Bull. 38, p. 277, 1914. 

33372°-25--9 
i26 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923-1924. 

by the writer. These points-namely, the 

structure and chemical nature of algae as then 

known and the unacceptability of the hypotheses of bituminous affinity and the fundamental jelly as proposed by Renault and Bertrand-were sufficient in the writer's mind to 

overthrow the algal theory. 

On the other hand, the writer could not agree 

that the yellow bodies in the bogheads were 

invariably spores. The kerosene shales of New 

South W:ales, the typical Reinschia coals, stood 

out most clearly as contravening the theory of 

spore origin, and the bodies of unknown origin 

in the cannel coal from the Pottsville of Kentucky could not be classed as spores. For this 

reason the boghead and cannel coals have been 

objects of thought and investigation from time 

to time. Their nature and structure have now 

been fairly well worked out. 

The boghead coals that have been studied 

were the kerosene shales from N ewnes, New 

South Wales; bogheads from Torbane Hill and 

from Bathgate, both in Scotland; and American 

bogheads from Alaska and from Kiskiminetas 

Junction, Pa. 

STRUCTURE OF THE YELLOW BODIES COMPOSING 

CERTAIN BOGHEAD COALS. 

The organism that gave rise to these boghead 

coals was colonial-that is, a number of individuals were united into a larger body. (See 

Pis. XXXII-XXXVII.) In many places a 

number of such colonies were united into a 

larger mass. Some of the colonies were a pparently in the form of a hollow sphere. 

The protoplasmic or living part of the organism was of an oval form, as shown in thin 

sections and illustrated in Plates XXXIII, B)· 

XXXIV, A)· XXXV, B)· XXXVI-XXXVIII, 

A, and was surrounded by a relatively thick 

cell wall. This constituted a unit cell or 

organism. A considerable number of these 

were joined together into spherical bodies or 

colonies by a matrix of slightly different character. Whatever the nature of the cell wall 

and its cementing matrix, they were resistant 

enough to withstand weathering, putrefying, 

and oxidizing agencies and the coal-forming 

processes so well as to retain more than half of 

their original volume. Their structure points 

clearly to an organism other than spore matter 

of any plant. 

THE BOG HEAD-FORMING ORGANISM. 

The kind of organisms that gave rise to the 

bogheads is clearly represented by an oilbearing organism now living in salt lakes and 

salt lagoons of South Australia and surrounding islands. A recent study of this organism 

has shed much light on the nature of the yellow 

bodies composing the boghead coals and on the 

formation of the bogheads themselves. 

The exact position of the organism in the 

plant kingdom, together with its life history 

and habits, are yet unknown and are still under 

investigation. It resembles in some respects 

certain of the blue-green algae, but in the natur~ 

and chemistry of the cell wall it differs greatly 

from the ordinary blue-green algae. 

As no family or genus group to which this 

organism could be assigned is described in 

monographs such as Engler and Prantl's "Die 

natiirlichen Pfl.anzenfamilien" or Toni's" Syllogoge algorium," a new name had to be found for 

the organism. The name Elaeophyton,26 meaning oil plant, is therefore suggested. As the 

plant examined was found near The Coorong, 

the specific name coorongiana is also proposed. 

At the end of each winter a green scum 

called "seepage material" is formed on the 

lakes and lagoons and is blown by the prevailing winds to the southeastern shores. As the 

hot weather. progresses and the lakes dry up 

this material is deposited on the sand of the 

bank and quickly dries and solidifies into large 

sheets of a rubber-like dark-brown material, 

called coorongite. This material has been the _ 

object of much discussion, and all endeavor to 

discover its origin has heretofore been unsatisfactory.27 

Samples of both the green seepage material 

and the coorongite were obtained through the -

courtesy of Mr. John Claffey, of Adelaide. 

The organisms are colonial: a considerable 

number of unit individuals or cells are associated into colonies and form globules just 

vi':lible to the naked eye. · (See Pl. XXVII, A.) 

26 On account of the resemblance of this organism to forms that are 

often termed cocci and the large amount of oil it yields, the name 

Elaeococcus was first proposed for it by the writer and has appeared in 

print. But it was found that the term Elaeococca had been applied by 

Moritz Hill to one of the Euphorbiaceae found in Japan and China, 

Elaeococca vernicia. The name Elaeococca therefore has priority over 

Elaeococcus, which had to be abandoned. 

27 Data from personal communication from John Claffey, of Adelaide, 

South Australia. 
ORIGIN OF THE BOGHEAD COALS. 12'7 

These colonies may be either single or compound; in the latter type a number of single 

or primary colonies are united. A number of 

colonies may be coalesced into larger globules 

(Pl. XXVII, A), or a larger number of colonies 

may in turn be united into a .large mass 

(Pl. XXVII, B). Plate XXVIII, A, represents 

a stained colony at a high magnification, somewhat flattened under the cover glass. 

The structure may be best seen through 

stained thin sections. The section of a single 

colony, as on Plate XXVIII, B, shows it to be 

composed of an outer zone of · living cells, 

usually several cells deep, irregularly forming 

a thick spherical shell. This shell incloses a 

number of irregular cells of variable size and 

without protoplasmic contents, thus forming 

a central blank core. Plate XXVIII, B, shows 

several colonies. Usually several primary colonies are coalesced in to secondary or compound 

colonies, in which the central blank cores of 

the primary colonies are in communication 

with one another. (See Pl. XXIX.) 

The protoplasmic or living part of the cells 

is of an oval shape and relatively small, not 

over 5 microns (0.0002 inch) in length and 3 

microns in diameter. No definite nucleus is 

distinguishable, but the whole cell content 

takes up a nuclear stain· and is shown as a 

granular mass. In the living condition it contains chloroplasts of a blue-green color (Pls. 

X...1CX, XXXI). The protoplasmic part is surrounded by a relatively thick colorless cell wall 

of a clear and not particularly firm consistency, 

which stains with difficulty. The cell walls of 

the several individuals are cemented together 

by slightly denser matter of similar appearance, 

which, however, stains more readily (Pl. 

XXXI). As shown in Plates XXVIII,B, and 

XXIX, the active living cells are formed 

irregularly into a · thick zone, several to many 

cells deep, inclosing a group of blank cells in 

the center. These central blank cells are on 

the whole larger but are more variable in size, 

are irregular in shape, and together form a 

looser structure than the outer living cells 

(Pls. XXIX, B)· XXX; and XXXI, B). 

Where several colonies are united into larger 

secondary colonies, the cells at the junction 

have mtner lost their protoplasmic contents or 

have been squeezed out and replaced by the 

cent:tal blank cells. (See Pl. XXIX, A.) A 

colony or a larger number of colonies form a 

soft, flexible, but not mobile nor waxy mass. 

When they are placed under a cover glass considerable pressure is required to flatten or 

spread them out. 

The cell walls lend the organisms their 

peculiar properties. They do not decay or 

putrefy when exposed to the air in mass but 

congeal into a rubbery, elastic mass, which 

does not undergo further marked changes and, 

as already noted, forms the substance called 

coorongite. They are not composed of pectin, 

mucin, pectocellulose, or mucocellulose, as in 

ordinary algae, but consist largely of oils or oily 

substances, the nature of which is under 

investigation. 

COORONGITE. 

ORIGIN. 

There can be no doubt that coorongite is 

formed from the green seepage material or mass 

of living Elaeophyton. When a mass of the 

green living organisms is exposed to the air it 

quickly changes its color to a dark brown or 

grayish black and congeals to an elastic, rub herlike mass, exactly like the coorongite, in which 

the colonies and individual organisms and their 

structure are more or less clearly discernible,. 

together with a small amount of extraneous: 

matter, like sand grains, bits of plant tissues, 

cuticles, diatoms, and other algae. 

Coorongite as received from the field is 

plainly seen to be composed of the same 

organisms and contains the same kind of 

extraneous matter. Some of the colonies and 

individual cells of the organism are . very well 

preserved, others not so well; but even in the 

most poorly preserved material the characteristic structure is still recognizable. 

HISTORY. 

Coorongite was discovered in 1865 on the 

shores of The Coorong, in South Australia. It. 

has been variously known and described as 

Australian caoutchouc, mineral gumboge, ela~ 

terite, elastic bitumen, and coorongite, and it 

has been the object of curiosity and discussion 

ever since its discovery. The discussions have· 

mostly concerned its origin, whether mineral or· 

organic, and they are so numerous and generally 

so· unauthoritative that it is impossible to give. 

even a summary of the ideas pres en ted •. 

A number of eminent scientists, however, 

have investigated coorongite and have made: 
128 SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY, 1923-1924. 

reports on it. Among these are Thisel tonDyer, ~:: Boodle/9 Cumming,30 Hofer/1 and 

Wiesner. 32 An accurate description of coorongite in the field is given by De Hautpick, 33 

who says: 

Coorongite is found in the depressed portions of 

occasionally submerged sandy plains of considerable 

extent and is spread upon the ground chiefly near the 

edges of the depressions at the high-tide mark. Coorongite occurs in this district spread over a great area 

in the form of cake lying on the sand without any 

connection with the ground on which it is deposited. 

It represents undoubtedly the solidification of some 

substance which previously floated on the surface of 

the water and then was deposited on the sand and 

gradually dried up, absorbing and uniting with, during the drying process, all matter that happened to 

come in contact with it. Coorongite is of various 

thickness from an inch to 1 foot, and in color and appearance it is closely ·akin to the so-called "paraffin 

dirt" of the Gulf coast oil fields of Texas and Louisiana. 

Coorongite shows a peculiar rubber-like texture. 

When moist the material breaks much after the fashion 

of "green cheese." _.o\lthough rubbery under compression, it does not resemble rubber in tenacitv or cohesion, and in this respect it is identical with its twin, 

the "paraffin dirt" of America. It is clear, then, that 

coorongite is not a caoutchouc, although in appearance 

and color it resembles caoutchouc. It is soft, flexible, 

and easily cut, clammy to the touch, yet does not soil 

the skin. It has a characteristic " swampy" or 

"mucky" odor when wet and a characteristic odor of 

humic soils when moist. If the material is brought into 

suspension in water, very fine sand settles out and 

may be recovered by successive washing and decantation. When moist, it is gelatinous but neither markedly adhesive nor plastic. It is easily affected bv water 

but is insoluble therein. In thin slips it burn~ like a 

taper, melting before the flame, which is smoky. 

A substance very similar to coorongite, called 

n'hangellite, is found in Portuguese East Africa. 

Boodle 34 quotes a report made by J. Gething 

Hancock as follows: 

N'hangellite is an elastic description of bitumen and 

may be termed a mineral india rubber. It is clark 

green in color and is lighter than water and ha.s probably been formed in the oxidation of petroleum. It is 

most prevalent in the plain to the north and northwest 

of Lake N'hangella and to a large extent may be de28 Thiselton-Dyer, W. T ., On a substance known as Australian 

caoutchouc: Jour. Bot., 1872, pp. 103-106. · 

29 Boodle, L. A., N'hangellite and coorongite: Roy. Bot. Gardens, 

Kew, Bull. 5, pp. 146-151, 1907. 

30 Cumming, A. C., Coorongite, a South Australian elaterite: Chern. 

News, vol. 87~ pp. 306-308, 1903. 

31 Hofer, Hans, Das Erdol und seine Verwandten, pp. 262-264, 1922. 

a2 Wiesner, Julius, reviewed by Hofer, op. cit. 

33 Hautpick, E. de, Coorongite, a petroleum product: Australian Min. 

Standaxd, 1923, pp. 100Q-1001. 

34 Boodle, L. A., N'hangellite and coorongite: Roy. Bot. Gardens, 

Xew, Bull. 5, pp. 145-151,1907. 

scribed, as far as this neighborhood is concerned, as 

peculiar to that locality. 

The n'hangellite in occurrence is generally about 

half an inch in thickness and lies in patches varying 

from a few square yards to probably half an acre in 

extent. It is chiefly found in long, narrow strips on 

the surface anticlines of slightly undulating ground 

and gives the impression that it has been washed there 

by water, having largely the appearance of a high-tide 

mark. On the other hand, it is occasionally found in 

small pans, again indicating that it has been taken 

there by water and remained after the water had subsided. * * * I made the most searching inquiries 

* * * and was informed by many that after the 

rains it is possible to see this deposit gradually collecting and that it is then of a light-brown color and 

gelatinous in appearance. 

Boodle's description of n'hangellite is as 

follows: 

Specimens of this substance, when examined microscopically, prove to consist of a yellowish matrix, in 

which are embedded diatoms, sand grains, and sometimes sponge spicules, pollen grains, spores, etc.; but 

these inclusions are unimportant, forming only a small 

proportion of the mass. Fungal hyphae are also present and are often crowded and very distinct near the 

surface of the specimens, more sparse and forming an 

irregular reticulum in the interior. 

The yellowish matrix, when examined in thin sections under a high power, is usually seen to contain numerous very small cells, which are more refractive and 

for the most part more colored than the substance in 

which they are embedded. The latter may appear 

colorless in very thin sections, while the cells in question are yellow or brownish or pale green. They are 

usually elongated, and their sectional shape is elliptical 

or pyriform, or circular when seen in end view. In 

length they vary from 2 to 6 microns, or occasionally 8 

microns, and their breadth may be about half as great 

or more. Frequently no definite arrangement can be 

distinguished, but occasionally in favorable places one 

can demonstrate that the cells are grouped in colonies, 

which appear to be roughly spherical when small, 

elliptical or botryoidal when large. The cells are arranged so that their length is radial with regard to 

the colony, in which they form a peripheral layer, one 

or sometimes two or more cells thick. Their lateral 

distance from one another is variable but generally 

greater than their own diameter. When rather 

crowded, they are sometimes clearly arranged in pairs 

or groups of four. The substance in which the cells are 

embedded shows no structure and might well be the 

product of mucilage only. It is only here and there 

that colonies. of definite shape can be distinguished; 

the scattered arrangement of the cells in other parts of 

·the matrix may be explained as either due to flattening 

or distortion of colonies of similar form and size, or to 

the colonies having had indefinite growth, so that only 

young stages would show a regular form. 

From such details as can be determined there seems 

to be no doubt that the matrix has been derived from 
ORTGIN OF THE BOGHEAD COALS. 129 

a gelatinous organism belonging almost certainly to the 

blue-green alga~, among which it would be classed under the Chroococcaceae. Prof. G. S. West, F. L. S., 

who kindly examined the organism for me, agrees that 

it certainly appears to be a blue-green alga and compares it with Coelosphaerium Naeg. but adds that it is 

not exactly like anything with which he is acquainted. 

Its precise determination must be reserved until living 

material, or such as represents early stages in the formation of n'hangellite, can be obtained. Conversion 

into bituminous substance must imply extensive chemical changes in the mucilage, whereby the original 

characters of the alga may have been altered to some 

extent as regards the spacing and form of the cells. 

Changes have no doubt also taken place in the cell 

contents; hence the occasional greenish color of the 

cells may be secondary and not a remnant of their 

original pigment. On soaking or boiling a section in 

water the cells undergo a curious change; their cavities 

become enlarged and often appear as though empty, 

but when transferred to strong glycerine they gradually 

regain their original appearance. 

In some parts of the specimens the matrix shows no 

structure, but as the loss of structure is often not 

abrupt but preceded by a transitional boundary 

where the algal cells are collapsed or indistinct, it is 

probable that the structureless condition is secondary 

and due to more destructive changes than those which 

took place elsewhere. One may therefore assume that 

the whole of the matrix represents a gelatinous alga. 

This description tallies very closely with 

that of coorongite. 

CHEMICAL PROPERTIES. 

When heated in a tube coorongite will all 

melt, forming a sirupy liquid, which remains 

viscous after cooling. On distillation it yields 

large quantities of oil. 

An analysis made in a laboratory of the 

South Australian Government gave the following results: 

Analysis of coorongite. 

Moisture and volatile substances at 120° C_ _ 0. 8 

Gaseous distillates with acid reaction__________ 14. 0 

Oily distillate______________________________ 69. 2 

Tarry matter and coke______________________ 10. 1 

Mineral matter_-----------------------~--- 5. 9 

100. 0 

The oily distillate was redistilled and gave a 

series of oils of varying densities in the following fractions: 

Results of redistillation of oily distillate from coorongite. 

Fraction at 110° to 170° C__________________ 6. 7 

170° to 240° C _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 27. 7 

240° to 295° c__________________ 25. 3 

295° to 300° c__________________ 27. 3 

Residue___________________________________ 14. 0 

100. 0 

An ultimate analysis gave the following results: 

Ultimate analysis of coorongite. 

Moisture ___ ~---------------------------- Carbon _________________________________ _ 

Ilydrogen ______________________________ _ 

Ash ____________________________________ _ 

Fixed carbon ____________________________ _ 

Oxygen, etc _____________________________ _ 

0.46 

64. 73 

11. 63 

1. 79 

1. 005 

20. 375 

100. 00 

Analyses made in the Bureau of Mines laboratory at Pittsburgh gave the following results: 

Analyses of coorongite. 

Asre- Moisture Moisture 

ceived. free. and ash 

free. 

Proximate analysis: Moisture ___________ 1.6 -------- -------- Volatile matter ______ 90. 1 91.5 97. 2 

Fixed carbon ________ 2. 6 2. 7 2. 8 Ash ________________ 5. 7 5. 8 --------

100. 0 100. 0 100. 0 

Ultimate analysis: 

12. 0 Ilydrogen __________ 11. 3 11. 3 Carbon _____________ 73. 8 75. 1 79.7 

Nitrogen ___________ .7 .7 . 7 Oxygen ____________ 8. 4 7. 0 7. 5 Sulphur ____________ . 1 .1 . 1 Ash ________________ 5. 7 5. 8 --------

100. 0 100. 0 100. 0 

These figures agree fairly well with a number 

of determinations made by other analysts. 

Coorongite is partly soluble in carbon bisulphide, chloroform, ether, and benzol. A preliminary extraction with carbon bisulphide 

yielded about 70 per cent of soluble matter. 

The residue is of a tough, leathery consistency and has lost much of its elasticity. Besides the residue of the oil algae, it contains a 

few fragments of tissues and cuticles of higher 

plants, also mineral matter consisting of some 

diatoms and largely of sand. The ash amounts 

to 5.8 per cent in the untreated coorongite. 

All the insoluble extraneous substances have 

naturally been concentrated in the residue. 

The soluble matter is in the form of thick, viscous oil of a yellow color, which gradually 

turns darker on exposure to the air. 

Cumming 35 carried the investigations on 

the extraction with carbon bisulphide further. 

He obtained 24 per cent extract, leaving a resi35 Cumming, A. C., Coorongite, a South Australian elaterite: Chern. 

News, vol. 87, pp. 306-308, 1903. 
130 SHORTER, CONTRIBUTIONS TO GENERAL GEOLOGY, 1923-1924. 

due containing 30 to 40 per cent of ·ash. The nor undergo any further oxidation after the 

soluble matter therefore amounted to about 33 first change of color seems to account for the 

per cent of the original coorongite. This con- more or less complete preservation of the orsisted of a clear yellow, translucent, waxlike ganisms in coorongite. 

substance, which softened at 35° C. and was 

quite fluid at 42°. It was readily soluble in YELLOW BODIES OF BOGHEAD COALS COMPARED 

all proportions in benzene, ether, toluene, chloroform, and carbon bisulphide. Cumming 

was not able to saponify it and therefore concluded that it was of the nature of a mineral 

oil. Its composition (C, 77.92; H, 11.69; 0, 

10.39) and its molecular weight correspond to 

the formula (C10Ht80) 8 • 

The insoluble constituent was an unelastic, 

tough substance, which burned with a luminous 

flame, melted before the flame, and had an odor 

like burning fat. It was saponifiable with alcoholic potash. Its composition (C, 64; H, 10.52; 

0, 25.26) and molecular weight conform to the 

formula C10H180 3 • The chemical examination 

of coorongite and the ·oil derived from it has 

not been completed. 

CONCLUSIONS. 

The study of Elaeophyton therefore furnishes 

proof of the theory of the algal orgin of the 

boghead coals. The plan of organization, the 

structure, and even the form and size of the 

organism agree so closely with the corresponding character of the yellow bodies that constitute the boghead coals as to leave no room 

for doubt of their close biologic relation and 

their similarity in composition. The chemical 

nature of these organisms is so resistant to the 

agencies of putrefaction as to enable them, in 

a favorable environment, to survive the coalforming processes with more or less complete 

preservation in the forms found in the boghead coals. 

The most ll:nportant fact concerning Elaeophyton with reference to the formation of coorongite, in consideration of the theory that 

boghead coals owe their origin to similar organisms, is the chemical composition of its cell 

wall. The cell walls in the living organism are 

composed largely of oil or oily substances. No 

theory of chemical changes from cellulosic or 

mucous substances into an oil or fat is necessary. The oil is such in the living plant. 

There is probably a slight oxidation of some 

constituents but no radjcal change. The fact 

that the cell walls do not appear to putrefy 

WITH ELAEOP,HYTON. 

In the light of the structure and other features of Elaeophyton as above set forth, we can 

now return to the boghead coals and by COJilparison and analogy get a more complete idea 

of the nature and the structure of the organisms that formed them, . and so of the nature, 

structure, and origin of the fossil bogheads 

themselves. By comparison of horizontal sec- · 

tions at a lower magnification the similarity is 

evident. Plate XXXII, B, represents a horizontal section of the Australian kerosene shale 

containing Reinschia a'ustralis, and in comparing this with Plate XXVII, B, showing the 

living Elaeophyton, all magnified at 200 diam:-

eters, the resemblance is clearly shown. At a 

higher magnification, at which the cellular 

structure is more definitely brought out, the 

similarity is definitely shown and is seen to 

correspond to a striking degree. Although 

almost any of the illustrations will serve, the 

most surprising similarity is shown in Plate 

XXXI, A, representing the living organism, 

and Plate XXXIV, A, representing a section 

of the Australian kerosene shale. Plate 

XXXIII, B, illustrating Reinschia, also shows 

a striking resemblance. 

It should be remembered that a photograph 

will not represent all the structural featuPes 

as clearly as they can be seen directly under 

the microscope, where, by focusing up and 

down, the structure may be followed throughout. When the two forms are thus studied, 

and allowances are made . for . the changes 

resulting from coalification processes, no doubt 

is left as to their common origin. 

The yellow bodies in the boghead coals can 

now be interpreted as colonies and compounds 

of colonies, exactly as in the living material. 

The smaller yellow bodies represent primary 

colonies in the central part of which the blank 

cells may often be discerned (see Pls. XXXIV, 

A}· XXXV, B}· and XXXVI, A); others are 

fusions of two, three, or four primary colonies, 

in which also the blank cells may be recognized (Pl. XXXVII, A). Probably most of 
ORIGIN OF THE BOGHEAD COALS. 131 

the yellow bodies are of this kind; in others, 

the large yellow bodies, a large number of 

colonies are united. The outlines of the primary colonies can usually be distinguished in 

the compound colonies, as in the living material. (See Pis. XXXIII, B/ XXXIV, A_; 

XXXVI, A7• XXXVII, B7• XXXVIII, A.) 

The protoplasmic or once living parts of the 

organisms are represented by the darker areas 

shown in the illustrations, most of them clearly 

of an oval outline, though some are contorted 

and disarranged. In thin sections of the boghead coals these portions are shown to be oval 

or ovoid sacks, or contorted or shriveled-up 

sacks that once were ovoid. Usually the contents are brown to dark brown. However, in 

the bogheads from different localities· they 

may vary considerably in state of preservation, color, size, form, and definiteness of outline. In the Scotch torbanite examined, for 

example, the cell contents of Pila, the yellow 

body, are much lighter in color and may even 

be of the same color as the cell-wall matter, the 

coloring matter being absent, so that the cell 

wall is indicated merely by a line of different 

refraction. In the Australian kerosene shale 

the colonies of Reinschia are in many specimens particularly well preserved, and the sacks 

contain much brown coloring matter; for this 

reason these shales furnish most favorable 

material for study. Each of the brown sacks 

is surrounded by a light-colored, usually relatively thick wall, which in turn is embodied 

in a slightly darker material, the medium 

cementing the cells into colonies. The oval 

sacks with their surrounding cell walls are 

grouped in a zone toward the outside. This 

zone may be two or more cells deep. Their 

arrangement commonly is irregular-that is, 

there is generally no definite orderly arrangement. In this respect they are similar to 

the living form. At the central part of each 

of the multiple colonies is found a blank 

structure-that is, cells without the brown 

sacks. These undoubtedly are analogous to 

the blank cells of the living colonies of Elaeophyton. 

COMPARISON OF THE BOG HEAD COALS EXAMINED. 

In comparing with one another the boghead 

coals studied c.onsiderable differences in structure and the degree of preservation may be 

observed. Many of these differences are, 

however, possibly due to extrinsic causes and 

are not differences that existed in the organisms themselves when living. 

AUSTRALIAN BOGHEAD, OR "KEROSENE SHALE." 

The boghead coal from the W olgan Valley, 

New South Wales, in a formation of Permian 

age, is compact and homogeneous in its outer 

appearance and shows but little stratificati?n. 

It is of a dark or dull-brown color, breaks w1th 

a typical conchoidal fracture, and can not be 

made to split along any particular cleavage 

plane. 

As seen in thin sections, the yellow bodies, 

the colonies of Reinschia australis, are somewhat 

loosely packed. This is shown in Plate 

XXXII, A, in which the bodies are represented 

by irregular, elongated patches and the groundmass by the black areas. There is, however, a 

considerable difference in this respect in different parts of the same sample or even in the 

same thin section. The colonies or yellow 

bodies ·have been flattened considerably, the 

larger ones more than the smaller ones. The 

ratio of the larger diameter to the shorter 

averages about 2: 1; in the smaller bodies it , 

is 3:1. Most of the smaller bodies represent 

single colonies; the larger ones represent compound colonies. 

The colonies are embedded in an opaque, 

dirty-looking groundmass, which, in general, is 

composed of matter produced by organic degradation and a small amount of mineral matter. 

A large part of this organic matter is the result 

of degradation of the yellow bodies themselves; 

besides this, bits of plant tissues and plant 

fibers and remnants of cuticles form a very small 

part of it . Spores are n.ot numerous in this 

boghead but are invariably present, as is to be 

expected. 

The yellow bodies or colonies of Reinschia in 

this sample are the best preserved of all the 

a]gae in the boghead coals examined. There is, 

however, a considerable variation in their state 

of preservation. In some the structure is 

remarkably well preserved, every detail of the 

structure of the organism being intact; in 

others it is very obscure. Between these two 

extremes all shades of preservation may be observed. The sacks-that is, the once living 

protoplasmic contents-contain much brown 
132 SHORTER CONTR-IBUTIONS TO GENERAL GEOLOGY, 1923-1924. 

coloring matter, which differentiates them 

clearly from the remainder of the cell and also 

lends the section as a whole a brown color under 

the microscope. 

BOGHEAD COAL (TORBANITE) FROM TORBANE 

HILL, SCOTLAND. 

In its outward appearance the sample of boghead coal from Torbane Hill, Scotland, resembles an ordinary spore cannel coal. It is 

slightly laminated, and although the cross and 

oblique fracture is conchoidal in general, it will 

split along certain horizontal bedding planes. 

It represents the celebrated deposit of torbanite found in the Calciferous sandstone series, of 

MiE'sissippian age. 

As seen in thin sections, the yellow bodies, 

the colonies described as Pila scotica, are a 

little more closely packed than the colonies 

in the Australian shales and are not nearly 

so much compressed. This is clearly shown 

in an examination of the photographs of the 

cross section reproduced in Plate XXXIV, B, 

and in a comparison with the horizontal section in Plate XXXV, A. The groundmass is 

of the same appearance and probably of the 

indicative of the characteristics of a deposit 

for a considerable space around the sample. 

The material is from the Calciferous sandstone 

series, of Mississippian age. 

The yello-w bodies (colonies referred to 

Pila scotica) in the Bathgate boghead coal 

are considerably more flattened than those in 

the Torbane Hill deposit and have a more 

pronounced brownish color. (See Pls. 

XXXVI, B; and XXXVII, A.) The embedding medium is of the same appearance as 

that in the Torbane Hill boghead. The structure is much better preserved than that in 

the Torbane Hill coal but not quite as well as 

that in the Australian shale. The sacks are 

well preserved and well differentiated from 

the cell walls, owing to their dark-brown contents. The structure is very similar to that 

in the Australian boghead. The differences 

in preservation are due to outside influences; 

evidently the organisms that gave rise to the 

deposit at Bathgate and Torbane Hill were 

very simi1ar to those in the Australian deposits, 

to which they are most clearly related. 

BOGHEAD COAL FROM ALASKA. 

same composition as that in the Australian In outward appearance the Alaskan bogshales, though it is somewhat more opaque. head, according to the one sample on hand, is 

The sacks, or once living protoplasmic parts of very similar to an ordinary cannel coal. . This 

the cells, contain little or no brown coloring sample came from a district drained by Colville 

matter and hence are not well differentiated River; the exact locality and the geologic 

from the remainder of the cell. That they age of the beds are not known. It is compact 

are present is clearly revealed through a and dark grayish black. When examined at 

difference in refraction of the cells along the a low magnification (200 diameters), it presents 

borders of the sacks, although this may not the same general appearance as the boghead 

be reproduced distinctly in the photographs; coals from Scotland and Australia and at 

yet every photograph taken shows clear once gives the impression that it is of the same 

evidence of the structure. The lack of the kind. (See Pis. XXXVIII, B, and XXXIX, A.) 

brown coloring matter makes the sections of a But under a higher magnification it presents 

much lighter color than those of the Australian a marked difference, and offhand it gives the 

boghead. The algal colonies appear to have appearance of not belonging to the same kind 

suffered considerable changes during the peat ' at all. · The yellow bodies on the whole are 

stage and look as if they were waterworn. A somewhat smaller than in the samples precareful comparison shows that their general viously described, the large majority have no 

structure was very similar to that of the brown coloring matter in the sacks, and they 

Australian deposit. reveal no definite structure or only a faint 

Spores are invariably present in this coal, structure. But a careful survey of the secthough in relatively small numbers. tion.s, both horizontal and cross, discloses 

here and there yellow bodies whose structure 

BOGHEAD COAL FROM BATHGATE, SCOTLAND. has been well preserved . and whose entire 

Only one small sample from the deposit at 

Bathgate, Scotland, has been examine<;).. ~xperience shows, however, that one section is 

organization may be reconstructed. These 

show that the general structure is similar to 

that in the Australian boghead coal, if not the 
ORIGIN OF THE BOGHEAD COALS. 133 

same, and that they must have been derived 

from an organism of the same nature as that 

which gave rise to that coal. Between those 

that are well preserved and those in which 

little or no structure has been retained all 

grades of transition are found; and as the 

general appearance, nature, and form of all 

the yellow bodies are the same, it must be 

concluded that all were derived from the same 

source. 

The alga characterizing the Alaska boghead 

is almost certainly of the same nature and is 

probably closely related to those forming the 

yellow bodies in the other boghead coals here 

described, as well as the living Elaer>phyton. 

BOGHEAD COALS OF THE KISKIMINETAS REGION, 

PENNSYLVANIA. 

The boghead coal at Kiskiminetas Junction, 

Pa., in the region where Kiskiminetas River 

joins Allegheny River, is found in a thin bed, 

not more than 2 feet in thickness, in the limestone between the Upper and Lower Freeport 

coals, in the Allegheny formation, of Pennsylvanian age. It begins with an ordinary 

shale at the bottom, which quickly changes 

into a bituminous "slate" and then within a 

few inches into a rich boghead coal. It much 

resembles a bituminous shale throughout its 

thickness . . (See Pl. XXXIX, B.) It is laminated and wi1l split horizontally along certain 

bedding planes. 

In thin sections its resemblance to the other 

boghead coals is at once apparent. The 

yellow bodies are, on the whole, of the same 

size as those in the Alaskan boghead but 

smaller than those in the Scotch and Australian 

samples. · In general form and appearance the 

yellow bodies (Pl. XL, A) are the same as 

those in the other bogheads, but on comparison 

of the minute structure they are found to 

differ markedly, showing very little organized 

structure or none at all. Here and there the 

microscopist may imagine that he recognizes 

the brown sacks, but in the last analysis there 

is no positive proof of them. If conclusions 

were to be based upon the structure of the 

bodies in this coal alone, they would be relegated at once to the category of the unknown; 

but in looking over the bogheads from different 

places and considering the varying state of 

preservation of the structure, a continuous 

series can be constructed-at one end those 

in which the structure is perfectly preserved, 

gradually and imperceptibly grading into those 

at the other end, in which no structure is 

observable, the same or very similar general 

form, color, and nature being maintained 

throughout the series. Such a result gives 

strong support to the reasoning that the whole 

series is of the same origin. Such a series 

comprises the Australian bogheads, with the 

structure in a perfect state of preservation, at 

one end, and the Pennsylvanian bogheads, 

with no structure preserved, at the other. In 

this light, until further evidence is found to 

the contrary, it may be assumed that the deposit at Kiskiminetas Junction js of the oilalgal origin and a true boghead coni. 

CANNEL COAL FROM UPPER POTTSVlLLE FORMATIONS IN WESTERN PENNSYLVANIA AND 

EASTERN KENTUCKY. 

Samples of cannel coal from the upper Pottsville at Lesley, near Paintsville, Ky., were also 

examined. The bed at Lesley is approximately 5 feet 9 inches thick. At the bottom 

is a layer of ordinary bituminous coal about 

2,Y2 inches thick, changing soon into cannel 

coal, which continues to the top, with the 

exception of a 4-inch layer of stratified bituminous coal in the middle of the bed. The 

bed has a roof of rather gritty gray shale containing carbonized plant remnants and residues. 

The cannel is black and tough and cleaves 

in slabs of varying thickness; but the cross and 

oblique fractures are distinctly conchoidal. 

The cannel is really a spore cannel coal, because by far the larger part of the organic 

matter consists of spore matter. Spore exines 

of a number of different kinds, both microspores and megaspores, enter into its composition. Much macerated spore matter and some 

cuticular matter are observed in the ground 

mass.36 

Among the spore exines are peculiar yellow 

bodies in varying amounts, resembling those 

of the boghead coals in certain respects. No 

definite organized structure, however, can be 

discerned in them. These bodies have been 

described by the writer 36 as follows: 

The coal contains interesting objects that are very 

abundant in certain strata, where they constitute more 

36 White, D avid, and Thiessen, Reinhardt, The origin of coal: Bur. 

Mines Bull. 38, p . 253, 1914. 
134 SHORTER CONTRIBUTIONS TO. GENERAL GEOLOGY, 1923-1924. 

than half of the bulk. In other strata they are comparatively rare. On the whole, they constitute only 

a small proportion of the total mass. They are in 

general appearance distinctly similar to Renault's 

genus Pila of his supposed algae. 

These bodies vary greatly in size, ranging roughly 

from 30 to 17 5 microns in diameter. In color they are 

almost of a paraffin-white, which in thicker sections 

becomes a light brass-yellow. Their form is roughly 

oval, with an irregular outline. This irregularity 

consists of processes, often pseudapoda-like, arid 

irregular cavities or depressions, reaching often to the 

center or even through the body. 

The structure of these bodies is, in fact, so 

irregular that an adequate description of it is 

difficult. It is probable that these yellow 

bodies had their origin in an organism similar 

to that which gave rise to the Australian and 

European boghead coals. 

Numerous yellow bodies, apparently comparable to those · described in the foregoing 

pages, are found in a cannel coal occurring 

in the Mercer shale on Neshannock Creek near 

Leesburg, in Springfield Township, Mercer 

County, Pa. As shown in Plate XL, B, this 

coal contains much material of humic origin. 

Besides the spore exines and the yellow bodies, 

of which the latter are plainly recognizable 

in the photograph, the section discloses large 

numbera of cuticular fragments and numerous 

lumps of resin, two kinds of which, one dark 

and the other lighter, are seen on the left. 

It is likely that a close examination of cannel 

coals will reveal algal colonies in many of 

them, as is to be expected on account of the 

open-water environment in which they were 

lai~ down. In view of the interesting results 

of the present study of bogheads and cannel 

coals, a more systematic examination of the 

cannel series, of which abundant material is 

already in hand, is contemplated. 

SUMMARY. 

According to origin, bituminous shales and 

cannel coals may be classified into humic, spore, 

eerie, resinous, and algal deposits. 

This paper endeavors to show that the yellow bodies of the boghead coals are not derived 

from spores but represent colonies of alga-like 

organisms heretofore not well known. In all 

the bogheads investigated these colonies, described as Reinschia and Pila, are s~milar to 

an organism now living in the salt lakes and 

salt lagoons of South Australia and neighboring islands. The living organism has been 

termed Elaeophyton because of the large amount 

of oil it contains. 

Elaeophyton is a colonial organism in some 

respects resembling · some of the blue-green 

algae, but its cell wall differs from that of the 

algae ordinarily described. The colonies, which 

are just visible to the naked eye, may be single 

or compound; they are solid and of globular 

form. Each colony is composed of an irregular outer zone of living cells, several cells deep, 

inclosing a core of irregular ir~ner cells that 

lack protoplasmic contents. The living cell 

contents are of oval or ovoid form, are relatively small (about 3 microns in diameter and 

·5 microns long), and contain no definite nuclei. 

They are surrounded by a relatively thick cell 

wall of irregular thickness. The different cells 

are cemented together by a medium apparently 

similar to the cell walls. These colonies appear on the lakes and lagoons toward the end 

of winter, are blown to the shore, and there 

form a rubber-like mass called coorongite. 

Coorongite does not appear to decompose or 

oxidize further; it is rich in oil and volatile 

matter, burns with a bright, hot flame, and 

melts before burning. When heated in a closed 

test tube it melts into a sirupy liquid, becmning viscous on cooling. When distilled, it 

yields about 70 per cent of oils, some tarry 

matter, some gas, and very little solid residue. 

Coorongite is the peat stage of boghead coal. 

The structure and size of the yellow bodies 

in the boghead coals examined correspond 

closely to those of the colonies of Elaeophyton. 

The yellow bodies contain an outer zone of 

thick-walled cells inclosing oval sacks, most of 

which have brown contents. These sacks represent the once living protoplasmic contents of 

the cell. The preservation of the structure as 

a whole differs in deposits at different localities, the coals examined showing a range from 

a very well preserved structure to a condition 

in which the structure has been completely 

effaced. A similar range occurs to some extent 
ORIGIN OF THE BOGHEAD COALS. 135 

in the deposits of well~preserved material. By 

analogy and through the similarity in structure, appearance, and qualities of the yellow 

bodies in the boghead series, it is concluded 

that all had a similar source--that is, colonial 

algae of the same general nature and of a conl.-

position similar to that of the colonies of the 

living Elaeophyton. 

ACKNOWLEDGMENTS. 

In addition to numerous suggestions made 

by members of the Bureau of Mines staff, whose 

names need not be mentioned, the writer is 

indebted for extensive and constructive criticism to David White, most of whose sugges- · 

tions have been incorporated in these notes. 
PLATES XXVII-XL 

137 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 132 PLATE XXVII 

A. COLONIES OF THE LIVING ONE-CELLED ALGA, ELAEOPHYTON N. GEN., FROM THE COORONG 

DISTRICT, SOUTH AUSTRALIA 

Single as well as compound colonies are shown. The size of the compound colonies depends on the number of primary colonies in them. The small bodies are apt to be single colonies, the larger ones compound colonies. X 200 

B. A NUMBER OF COLONIES OF ELAEOPHYTON MERGING INTO A LARGER MASS 

The black specks represent the living cell contents. X 200 
U. S. GEOLOGICAL SUR VEY P ROFE SSION AL PAPER 132 PLATE XXVIII 

A. A COLONY OF THE LIVING E~AEOPHYTON, COMPRESSED UNDER THE ·coVER GLASS AFTER 

STAINING WITH SAFRANIN 

The dark oval or pvoid spots represent the living cell contents. At many points the outlines of the cell walls are shown. 

X 1,000 

B. SECTIONS OF SEVERAL COLONIES OF ELAEOPHYTON, TWO OF WHICH SHOW THE CORE OF INNER 

BLANK CELLS. X 600 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 132 PLATE XXIX 

A. SECTION OF A SMALL COMPOUND COLONY OF ELAEOPHYTON 

Showing the thick zone or shell of living cells, and the structure of the inner core of blank cells. X 600 

B. SECTION OF COMPOUND COLONY OF ELAEOPHYTON AND OF AN ADJOINING SINGLE COLONY 

Showing the blank inner tissue surrounded by an outer zone of living cells. X 600 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 132 PLATE XXX 

A. SECTION OF COMPOUND COLONY OF ELAEOPHYTON AND PARTS OF NEAR-BY COLONIES AT A 

HIGHER MAGNIFICATION 

Plates XXX and XXXI show more definitely the organization of the individual cells. The oval dark spots represent the contents of the living cell, the lighter area bordering each of these spots represents the reinforcement of fatty or oily matter deposited inward on the primary cell wall, and the darker heavy lines surrounding the cells and uniting them represent the cementing matter. The lighter areas of irregular structural pattern represent the blank cells. The irregular 

light strips represent open spaces between the colonies. X 1,000 

B. SECTION OF COMPOUND COLONY OF ELAEOPHYTON 

Showing in particular the aspect and variation of the blank cells in the center of the colony. X 1,000 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 132 PLATE XXXI 

A. SECTION OF COMPOUND COLONY OF ELAEOPHYTON 

Showing the thick fatty matter deposited about the cavity of the cell and forming its thick wall. Compare this figure with Plate XXXIV, A. X 1,000 

B. SECTION OF COMPOUND COLONY OF ELAEOPHYTON 

Showing variability in size, form, and aspect of blank cells; also relations of fatty inner cell thickening about the central cavity to the cementing matter and the blank cells. X 1,000 
U. S. GEOLOGICAL SURVEY 

A. CROSS SECTION OF BOGHEAD COAL (THE SO-CALLED KEROSENE 

SHALE) OF PERMIAN AGE FROM THE WOLGAN VALLEY, NEWNES, 

NEW SOUTH WALES, AUSTRALIA 

The irregular, light, somewhat spongy masses that form "yellow bodies" in this fossil deposit are the compound colonies of the one-celled alga Reinschia australis B. 

Renault. X 200 

PROFESSIONAL PAPER 132 PLATE XXXII 

B. HORIZONTAL SECTION OF BOGHEAD COAL OF PERMIAN AGE FROM 

THE WOLGAN VALLEY, NEWNES, NEW SOUTH WALES 

The section shows large and small colonies of Reinschia australis B. Renault. X 200 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 132 PLATE XXXIII 

A. HORIZONTAL SECTION OF BOGHEAD COAL OF PERMIAN AGE FROM THE WOLGAN VALLEY, NEWNES, NEW 

SOUTH WALES, AUSTRALIA 

This section shows compound colonies, mostly of rather small_size, of the fossil alga Reinschia australis B. Renault. X 200 

B. HORIZONTAL SECTION OF BOG HEAD COAL OF PERMIAN AGE FROM THE WOLGAN VALLEY, NEWNES, 

NEW SOUTH WALES, AUSTRALIA 

More highly magnified to show a number of primary colonies of the fossil alga Reinschia australis B. Renault. The dark oblong spots represent the remains of the contents of the living cells, now stained dark by biochemical decomposition 

pmducts more or less distinctly humic. X 1,000 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 132 PLATE XXXIV 

A. HORIZONTAL SECTION OF BOGHEAD COAL OF PERMIAN AGE FROM THE WOLGAN VALLEY, 

NEWNES, NEW SOUTH WALES, AUSTRALIA 

Showing oolonies varying in size of the fossil alga Reinschia ·australis B. Renault, characteristic of the kerosene shale. The more completely the rock is made up of these colonies of fatty algre the more voluminous the distillate and the better 

its quality. X 1,000 

B. CROSS SECTION OF BOGHEAD COAL (TORBANITE) OF MISSISSIPPIAN AGE FROM TORBANE HILL, 

SCOTLAND 

The section shows the colonies of the one-celled alga Pila scotica B. Renault, now fossil and embedded in a general attritus of dark-brown color. But little flattening has taken place. X 200 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 132 PLATE XXXV 

A. HORIZONTAL SECTION OF BOGHEAD COAL (TORBANITE) OF MISSISSIPPIAN AGE FROM TORBANE 

HILL, SCOTLAND 

The colonies of the fossil one-celled alga Pila scotica B. Renault, which form the "yellow bodies," are embedded in an attrital matrix of dark-brown color, "the groundmass," in which is mingled a considerable amount of dirt. The large macerate:i 

body at the top appears to represent the fossil organism described by B. Renault as Cladiscothallus, a fungus. X 200 

B. HORIZONTAL SECTION OF A COLONY OF PILA SCOTICA B. RENAULT FROM THE SAME LOCALITY 

AND DEPOSIT AS THE SPECIMEN ILLUSTRATED IN A 

Shows an outer zone of cells surrounding the inner core of blank cells in the fossil species just as in the living Elaeophyton. The brown cell contents of some of the cells are distinguishable. The algae of the colonies are slightly decomposed around the edges of the colonies. X 1,000 
U. S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 132 PLATE XXXVI 

A. HORIZONTAL SECTION OF AN ALGA COLONY, PILA SCOTlCA B. RENAULT, IN THE BOGHEAD COAL 

(TORBANITE) OF MISSISSIPPIAN AGE FROM TORBANE HILL, SCOTLAND 

The primary colonies are easily distinguishable; also the inner core of blank cells. The brown oval contents of the cells have largely disappeared, as is common in this bog head coal, but the outlines of the cells are still visible through a difference in 

refraction. X 1,000 

B. CROSS SECTION OF BOGHEAD COAL OF MISSISSIPPIAN AGE FROM BATHGATE, SCOTLAND 

The "yellow bodies," compound colonies of the one-celled algoa Pila scotica B. Renault, have been much more flattened than are those in the deposit at Torbane Hill. (See PL XXXV.) The blank cells of the core of the colony have been more flattened than the individual algae, thus giving the colony the appearance of a highly sculptured spore exine. X 1,000 
U. S. GEOLOGICAL SUHVEY PROFESSIONAL PAPER 132 PLATE XXXVll 

A. CROSS SECTION OF BOGHEAD COAL OF MISSISSIPPIAN AGE FROM BATHGATE, SCOTLAND 

The "yellow body" in the central part of the photograph is clearly shown to be a compound colony of the one-celled fossil alga Pila scotica B. Renault. The primary colonies are well marked off. X 1,000 

B. HORIZONTAL SECTION OF BOGHEAD COAL OF MISSISSIPPIAN AGE FROM BATHGATE, SCOTLAND 

The outlines of the cell3 of the individual algae (Pila scotica B. Renault) in this highly magnified thin section are rather clearly shown. and the brown oval cavity which once contained the protoplasm of t he alga is shown distinctly. X l,OUO 
U. S. GEOLOGICAL SURVEY 

A. HORIZONTAL SECTION OF BOGHEAD COAL OF MISSISSIPPIAN AGE FROM 

BATHGATE, SCOTLAND 

This section outlines the primary colonies of the oil-forming fossil alga Pila scotica B. Renault, and the brown cell contents are. clearly distinguishable. This and the four preceding illustrations should be com _pared with the photographs of the living Elaeophyton shown in Plates XXIX, 

XXX, and XXXI. X 1,000 

PROFESSIONAL PAPER 132 PLATE XXXVIII 

B. CROSS SECTION OF A BOGHEAD COAL FROM COLVILLE RIVER, ALASKA, SHOWING YELLOW BODIES 

The obscurely indicated structure is comparable to that of the living Elaeophyton and to the fossil alga colonies characteristic of the kerosene shale (torbinate) and other bogheads. The Alaska yellow bodies also are probably compound colonies of a related alga. X 209 
U. S. GEOLOGICAL SURVEY 

A. HORIZONTAL SECTION OF BOGHEAD COAL FROM COLVILLE RIVER, 

ALASKA 

The similarity between the yellow bodies in this fossil deposit of unknown age in Alaska to the compound colonies of Elaeophyton (see Pl. XXVII) and to the fossil boghead algae of different ages is at once apparent. X 200 

PROFESSIONAL PAPER 132 PLATE XXXIX 

B. VERTICAL SECTION OF BOGHEAD COAL, LYING MIDWAY BETWEEN 

THE UPPER AND LOWER FREEPORT COALS, IN THE ALLEGHENY 

FORMATION AT KISKIMINETAS JUNCTION, WESTMORELAND 

COUNTY, PA. 

The organic matter in this deposit is composed very largely of yellow bodies, appar- ently comprising algal colonies closely comparable in general aspect and to a degree at least in structure with Elaeophyton and the fossil types of boghead colonial algae. Relatively very few spores are present. The deposit begins with an ordinary shale at the bottom, which first gradually and then quickly changes into a rich boghead 

coal. X 200 
U. S. GEOLOGIC,AL SURVEY 

A. CROSS (VERTICAL) SECTION OF CANNEL COAL FROM A FREEPORT 

BED OF THE ALLEGHENY FORMATION AT KISKIMINETAS JUNCTION, 

WESTMORELAND COUNTY, PA. 

The yellow bodies in this section, here seen in greater enlargement, are strongly suggestive of Elaeophyton and are probably alga colonies ~similar in general composition to the living and the fossil forms shown in the precedin~ illustrations. X 1,000 

PROFESSIONAL PAPER 132 PLATE XL 

B. CROSS (VERTICAL) SECTION OF CANNEL COAL FROM THE MERCER 

SHALE (UPPER POTTSVILLE) ON NESHANNOCK CREEK NEAR LEESBURG STATION, PA. 

This section shows spore exines, lumps of resin (at left), and a number of yellow bodies, 

probably colonial algae related by nature and composition to Elaeophyton. The section exhibits the characteristic aspect and constitution of a cannel coal in which spore exines predominate and in which occur also minor amounts of reilin lumps, 

alga colonies, fragments of cuticle, etc. X 200