Journal of the Institute of Petroleum, Vol. 26, No. 201

P . 1 0 1 ( 1 , 0

J O U R N A L OF

T H E I N S T I T U T E

O F P E T R O L E U M

F O U N D E D 1 9 1 3 I N C O R P O R A T E D 1 9 1 4

V o l . 2 6 J U L Y 1 9 4 0 N o . 2 0 1

C O N T E N T S

PAGE

Classification of Oil Shales and Cannel Coals. By A. L. Down and G. W . H im us . . . .

329

E rrors in Acid-Bottle Readings. By G. H. Scott .

349

Use of Bitumen Emulsion in Soil Stabilization. By

A. E. Lawrence . . . . ■ - 3 5 7

Soil M echanics in Foundation Engineering. By R. L.

Jam es . . . . . . . .

365

Obituary . . . . . . . .

375

A bstracts . . . . . . . .

3 0 5 A

Book Review . . . . . . .

3 4 1 A

Books Received . . . . . . .

3 4 1 A

Institute Notes . . . . . . . i

Published by The Institute of Petroleum.

Address : c/o T he University of Birmingham, Edgbaston, Birmingham, 15.

Printed in Great Britain by Richard Clay and Company, Ltd., Bungay, Suffolk.

All rights of Publication or Translation are Reserved.

P r i c e

7

s.

6

d.

THE INSTITUTE O F PE T R O L E U M

C O U N C IL , 1 9 3 9 -4 0

PRESID EN T:

Prof. A . W . N ash, M .Sc.

A lfred C. Adam s Lt.-Col. S. J. M. Auld,

O.B.E., M .C., D.Sc.

Prof. J. S. S. Brame, C.B.E., F.I.C.

The Rt. Hon. Lord Cadm an, C .C .M .C ., D.Sc., F.R.S.

PAST-PRESIDEN TS :

T. Dewhurst, A.R .C.S.

A . E. Dunstan, D.Sc., F.I.C.

Sir Thomas H. Holland, K .C.S.I., K.C.I.E., D.Sc., F.R.S.

J. K e w le y, M .A ., F.I.C.

V IC E-P R ES ID EN TS:

A sh le y Carter, A.M .I.M ech.E.

C . D ailey, M.I.E.E.

F. H. C a rn e r, Ph.D., M .Sc., F.I.C.

M EMBERS O F C O U N C IL :

J. M cConnell Sanders, F.I.C.

F. B. Thole, D.Sc., F.I.C.

C . H. Coxon

A . Frank Dabell, M.I.Mech.E.

E. A . Evans, M.I.A.E.

E. B. Evans, Ph.D., M .Sc., F.I.C.

W . E. C o o d a y , A.R.S.M ., D.I.C.

A . C . Hartley, O.B.E., F.C .C .I.

Prof. V. C. Illing, M .A.

J. S. Jackson, B.Sc., F.I.C.

J. A. O riel, M .C., M .A.

E. R. Redgrove, Ph.D., B.Sc.

C . A . P. Southwell, M .C., B.Sc.

H. C. Tett, B.Sc., D.I.C.

A . Beeby Thompson, O.B.E.

A . W a d e , D.Sc., A.R.C.S.

W . J. W ilson, F.I.C., A .C .C .I.

C. W . W ood, F.I.C.

Arthur W . Eastlake, A.M .I.M ech.E., H onorary Secretary

H O N O R A R Y E D IT O R : Dr. A . E. Dunstan H O N O R A R Y A S S O C IA T E E D IT O R : Dr. F. H. C a rn e r H O N O R A R Y T R EA S U R ER : The Rf. Hon. Lord Plender, C.B.E.

S E C R E T A R Y : S. J. A stbu ry, M .A .

V o l . 2 G . N o . 2 0 1 . Ju l y 1 9 4 0 .

T H E C L A S S I F I C A T I O N O F O I L S H A L E S A N D C A N N E L C O A L S . *

B y

A. L.

D o w n ,

P h .D ., A.R.C.S., D .I.C ., a n d G. W .

H im u s,

P h .D ., M .I.C hem .E ., A.R.C.S.

Sy n o p sis

A tte n tio n is d irec te d to th e confusion t h a t e x is ts in th e n o m en c latu re a n d classification of n a tu r a lly o c cu rrin g o il-yielding m a te ria ls . A sy ste m of n o m en c latu re b a se d o n th o p rin c ip a l p la n t a n d m in e ra l c o n s titu e n ts a n d a classification show ing th e in te r-rela tio n sh ip s a n d g ra d a tio n of p ro p e rtie s of th ese su b sta n c es is p u t fo rw ard .

A t

th e P len ary Session o f th e Conference on Oil Shale a n d Cannel Coal, held a t Glasgow in 1938, a resolution

1

was passed “ T h a t th e Council of th e I n s titu te o f P etroleum be in v ited to ta k e steps to secure a sta n d a rd nom enclature o f th e various oil-producing m aterials discussed or described in th e various papers su b m itte d to th e Conference.” T he u rg e n t need for such a stan d ard ized nom enclature, a n d also for a ra tio n a l classification, is a p p a re n t from even a b rief stu d y o f th e lite ra tu re . T he object o f th e p resen t p ap er is to suggest a ra tio n a l system of nom enclature, coupled w ith a te n ta tiv e classification which shall show th e inter-relationships betw een th e various classes o f oil-yielding m aterials. W hile i t is realized t h a t th e proposed classification is n o t final, in th e opinion o f th e a u th o rs i t is based on th e m ost satisfacto ry d a ta available, a n d m ay serve as a fo undation on w hich fu rth e r classifications can be developed as our knowledge o f th e chem istry of these m aterials increases.

G reat confusion has arisen from tw o m am causes— firstly, owing to th e indiscrim inate use o f th o term s “ oil shale ” a n d “ cannel coal,” and secondly, due to th e g re a t v arie ty of nam es w hich hav e been applied by different investigators to one p a rtic u la r ty p o of substance. T hus, different deposits containing large num bers o f algæ j (i.e., sim ilar to th a t a t Torbane- hill, Scotland) have been variously referred to as “ to rb a n ite ,” “ boghead coal,” “ algal coal,” “ a lb e rtite ,” “ stellarite,” “ b a th v illite ,” “ b itu m in ite ,”

“ kerosine shale,” “ brown cannel coal,” “ petroleum -oil-cannel-coal,”

“ w ollongite,” etc., th e la st four being special nam es w hich hav e been applied a t various tim es to th e N ew S outh W ales “ boghead ” or “ to rb a n ite .”

O f these nam es, only “ algal coal,” which was suggested b y B e rtra n d an d R e n a u lt

,2

gives any indication as to th o n a tu re o f th e m aterial. I n an y new system o f nom enclature i t is essential, first, to avoid nam es w hich have been w idely m isused h ith e rto , an d secondly, to em ploy term s descriptive of th e m ain co n stitu en ts o f th e m aterials.

* P a p e r re ce iv e d 1 1 th J u ly , 1939.

f A lth o u g h th e re h a s b een m u c h c o n tro v e rsy a s to th e p recise n a tu r e of th o y ellow b odies o rig in a lly called “ a l g æ ” b y E d g e w o rth D a v id in 1889, th e research es of K . B . B la c k b u rn a n d B . N . T e m p erly 5 h av e, in th o o p in io n of th e a u th o rs , sa tis fa c to rily s e ttle d th e q u e stio n in fa v o u r of th e a lg a l th e o ry .

A A

3 3 0 D O W N A N D H I M U S : T H E C L A S S I F I C A T I O N O F

Pr i m a r y Cl a s s i f i c a t i o n.

E x am in atio n of th e naturally-occurring m aterials from which oil can be o btained b y h e a t tre a tm e n t shows th a t th e y fall in to threo m ain classes : Class I, substances from which th e g reater p a rt o f th e organic m a tte r can be e x tra c te d by th e norm al solvents for p etro leu m ; Class I I , substances w hich yield 50 per cent, or m ore of th e ir organic m a tte r as a n oil on h e a t tre a tm e n t, b u t from w hich only a sm all p ro p o rtio n o f th e organic m a tte r can be ex tra c te d by solvents; a n d Class I I I , m aterial form ed alm ost entirely from highly altere d p la n t rem ains which yield only a b o u t 15 per­

cent. o f th e organic m a tte r as oil.

O il-yielding M a terials.

C l a i s L Class I I . Class I I I .

Ivorogen R o ck s. C oals of th e

O il S a n d s, O il S hales. P e a t A n t h r a c i t e

T a r S an d s, series.

B itu m in o u s L im e sto n es.

D ecrease in D ecreaso in

so lu b le oil y ield -j-

m a te ria l. organic m a tte r .

These m ain groups are by no m eans sharply defined, and interm ediate ty p es arc frequently m et. Thus, R . H . McKee, w orking on a sam ple from lo n e, California, obtained 10-98 per cent, e x tra c t w ith acetone and 10-1G p er cent, e x tra c t w ith chloroform , b o th of which are equivalent to ap p ro x i­

m ately 50 p er cent, o f th e oil yield on distillation. The gap betw een Classes I I and I I I is bridged b y th e v arie ty o f m aterials com m only referred to as cannel coals.

T he scope of th e p re se n t p ap er is confined to Classes I I an d I I I , th e de­

tailed work required for its extension to Class I n o t y e t hav in g been carried out.

Since th e nam es “ oil shale ” a n d " cannel coal ” hav e been frequently m isused, and since th e te rm “ oil shale ” is m isleading, w hilst “ cannel ” gives no indication of th e n a tu re o f th e m aterial to which i t is applied, it is advantageous to avoid using either. T rue oil shales contain no oil as such, th o oil is only form ed by th e d estru ctiv e distillation of th e organic m a tte r, to which Crum B row n applied th e nam e “ kerogen,” or “ oil-form er,” th u s th e m aterials in Class I I m ay be given th e general group-nam e “ kerogen ro ck s.” A n im p o rta n t d istinction betw een kerogen rocks an d coals is th e high p ro p o rtio n of m ineral m a tte r in th e form er. F o r th e m aterials bridging th e gap betw een Classes I I an d I I I (form erly know n as “ cannel coals ” ) th e general nam e “ kerogen coals ” is suggested since th e organic m a tte r yields a relatively high proportion of oil and th e y are freq u en tly associated w ith coals.

W hereas th e b anded c onstituents o f bitum inous coals m ay be sub-divided solely on a basis o f th e organic m a tte r, th e relatively sm all percentages of associated m inerals being u n im p o rta n t, in dealing w ith th e kerogen rocks th e chief m ineral c onstituents m u st be ta k en in to account. Only th e general

?• * i I 4 / f j

O I L s h a l e s a n d c a n n e l c o a l s. 3 3 1

diHerences can be d e te c te d from th e exam ination of h an d specim ens and, in th e p resen t s ta te of our knowledge, th e only satisfacto ry m eth o d of classification o f kerogen rocks is one based on th e ir principal organic constituents, as revealed by m icroscopic exam ination, an d th e n a tu re of th e associated m ineral m a tte r as determ ined by chem ical analysis.

Ge n e r a l Co n s i d e r a t i o n s o n Ke r o g e n Ro c k s a n d Ke r o g e n Co a l s.

I t is generally accepted th a t in th e g re a t range o f organic deposits of sedim entary origin, th e source-m aterial was vegetable m a tte r, an d anim al rem ains played little or no p a rt. S trong su p p o rt for th is view is found in th e w ork o f H . R . J . Conacher

,4

who m ade com parative te sts on (inter alia) norm al L evenseat oil shale an d on a sam ple from a b an d crow ded w ith shells of lin g u la ; he found th a t although th e shells caused considerable increase in th e percentage of ash, th e yields o f oil, w hen calculated on th e dry, ash-free basis, were identical w ithin th e lim its o f experim ental error.

M oreover, th ere was no appreciable difference betw een th e specific gravities a n d settin g points of th e oils from th e norm al shale a n d th e lingula band.

T he existence o f such a g reat range of re lated m aterials can be a ttrib u te d to tw o p rim ary causes : (i) differences in th e original p la n t m aterials, an d (ii) differences in th e conditions o f deposition an d th e subsequent h isto ry o f th e deposits. T he num ber of in term ed iate m aterials exhibiting a g rad atio n of p roperties arises from th e possibilities of m ixtures o f th e source m aterials in various proportions an d th e lim ited num ber o f proxim ate p la n t constituents. T here is no evidence to suggest th a t th ere has been any essential a lte ra tio n in th e com position or co n stitu tio n of these proxim ate p la n t co n stitu en ts th ro u g h th e ages.

Ke r o g e n Ro c k s.

T he kerogen rocks arc sedim entary deposits, containing organic m a tte r, o f w hich ap p ro x im ately 50 p er cent, is yielded as a n oil w hen th e rock is h ea te d to ab o u t 500° C .; th e y are very w idely d istrib u ted , occur in con­

tinuous seams, covering considerable areas, a n d m ay differ widely in age.

T hey are n o t usually in tim ately associated w ith coal seams. T he kerogen co n ten t is v ery variable, an d m ay range from 50 p er cent, u pw ards to practically zero.

E xam ples of kerogen rocks o f v e ry different geological ages are : E sth o n ian (Lower and Middle Ordovician), Swedish (Silurian), A m erican (T ertiary), A u stralian an d B razilian (Recent).

T he g re a t m a jo rity of kerogen rocks, w hen exam ined in th in sections u nder th e microscope, show unresolvable masses o f m acerated p la n t debris containing a few spores a n d /o r algae. This organic m a tte r can only be called “ kerogen,” hence th e rocks m ay be logically designated “ kerogen shales ” or “ kerogen lim estones,” according to th e p reponderating m ineral co n stitu en t. Sam ples are found in w hich th e organic m a tte r consists in g rea t m easure o f spores or algae a n d where these recognizable c o n stitu en ts p reponderate, i t is suggested th a t th e word “ kerogen ” should be replaced b y th e nam e of th e recognizable c o n stitu en t which predom inates.

T ypical photom icrographs o f representative kerogen rocks are show n in

Figs. 1 to 4.

3 3 2 D O W N A N D H M D S : T I I K C L A S S I F I C A T I O N O F

Ke r o g e n Co a l s.

K erogon coals are carbonaceous m aterials in w hich th e organic m a tte r is p re p o n d eran t; th e y occur in lenticular patches, usually over a very lim ited area, a n d o ften associated w ith bitum inous coals, w ith which th ey m ay fo rm aco m p o u n d seam , or in to which th e y m ay grade eith er laterally or vertically. The m a jo rity o f kerogen coals w hich hav e been described are o f Carboniferous or Perm o-Carboniferous age.

U nder th e microscope, th in sections show th a t th e kerogen coals contain m uch m acerated p la n t debris w ith considerable num bers of either algae or

spores, or b o th spores a n d algae.

A num ber of these m aterials have been illu stra te d a n d described b y W . J . Skilling

.6

Am ong these are th e following : Low er D y sa rt, Fife, yielding 23-1 per cent, ash, is a n algal c o a l; th e H u m p h (16-2 p er cent, ash) is a spore coal, while th e 18-inch seam , New Cumnock, A yrshire (16-2 per cent, ash), w hich contains b o th algae an d spores, is a n in term ed iate ty p e, or a n algal-spore coal. O ther exam ples of algal-spore coals are th e Mercer, P ennsylvania, illu strated by R . Thiessen

,7

an d th e K en tu ck y , illu stra te d by E . C. Jeffrey

.8

D eposits are know n th e organic co n stitu en ts of which are sim ilar to those o f a n algal coal, b u t which co n tain large proportions (50 per cent, or more) of m ineral m a tte r, pred o m in an tly clay, an d owing to th is high m ineral content, these m aterials m u st be classified as algal shales, form ing a link betw een th e tw o m ain groups o f kerogen rocks a n d kerogen coals. T he Erm elo algal shale consists o f masses o f alga; em bedded in a groundm ass of unresolvablo p la n t debris, as shown in th e photom icrograph, Fig. 5. The proxim ate com position of th is m ate ria l shows i t to co n tain kerogen and m ineral m a tte r in approxim ately equal p ro p o rtio n s; th e m ineral m a tte r consists o f clay plus excess silica, w ith only 0-5 per cent, of carbonates.

The P a rro t R ough (Skilling, b e . cit.) is a sim ilar m aterial.

T here is a related group in which th e organic m a tte r consists alm ost entirely of alga), and in w hich th e m ineral m a tte r m ay v a ry from as little as 5 p er cent, to as m uch as 30 p er cent. These m aterials are a special interm ediate ty p e betw een algal coals a n d algal shales, for which th e only logical nam e is “ algal ro c k ,” since algie are th e only im p o rta n t constituent.

T h a t so few algal rocks are know n is due to th e r a rity o f th e occasions when th e requisito enorm ous num bers o f algaa, free from appreciable q u an tities of extraneous vegetable m aterials, becam e accum ulated an d preserved.

The spore coals grade insensibly in to th e d u ra in of bitum inous coals.

The foregoing conclusions as to th e properties, differences, a n d in te r­

relationships of these groups of m aterials have been set o u t in ta b u la r form .

Co n c l u s i o n s.

1. N a tu ra lly occurring oil-yielding m aterials can bo p rim arily divided according to th e solubility of th e organic con stitu en ts in th e usual solvents for petroleum .

2. T he insoluble m aterials can be divided in to kerogen rocks, kerogen coals, an d m em bers of th e p e a t-to -a n th racito series.

3. The various groups can be sub-divided according to th e chief p la n t

K I M E R I D C E K E R O G E N S H A L E , N O R F O L K , S H O W I N G L A M IN A T E D O R S H A L E Y S T R U C T U R E A N D M A C E R A T E D P L A N T D E B R I S . X 1 5 0 .

[To face p. ^{3 3 2 .}

B R O X B U R N M A IN K E R O G E N S H A L E . S C O T L A N D , S H O W IN G L A M IN A T E D O R S H A L E Y S T R U C T U R E A N D M A C E R A T E D P L A N T D E B R I S . V E R T I C A L S E C T I O N . X 150.

H o riz o n ta l.

,)■

V ertical.

Fid. 3.

T A SM A N IA N " S P O R E S H A L E S H O W IN G T H E G R E A T P R E P O N D E R A N C E O P C R U S H E D S P O K E C A S E S A N D T H E A B S E N C E O F O T H E R P L A N T R E M A IN S . X 150.

E S T H O N I A N A LG A I, L I M E S T O N E , W IT H G R E A T A C C U M U L A T IO N O P A L G A L C O L O N IE S T O G E T H E R W IT H P I E C E S O F S H E L L S . H O R IZ O N T A L S E C T I O N . X 150.

Fig. 4.

H o riz o n ta l.

V ertic al.

Fig. 5.

E R M E L O A L G A L S H A L E , S O U T H A F R I C A , S H O W I N G A L G A L C O L O N IE S I N A D A R K U N R E S O L V E D M A T R IX . X 1 5 0 .

co n stitu e n ts as seen in th in sections u nder tho microscope, an d th e n a tu re o f th e m ineral m a tte r, where im p o rta n t.

4. A ra tio n a l nom enclature is based on th e n a tu re o f tho p la n t rem ains plus th e n a tu re of th e m ineral m a tte r (where im p o rtan t), prefixed b y an adjective ex p lan ato ry of th e locality from which tho ma terial w as obtained.

Ac k n o w l e d g m e n t s.

W e desire to express our th a n k s to Professor A. C. G. E g erto n , E .R .S ., for his continued in terest in th e researches on oil-yielding m aterials, a n d to D r. R . Crookall o f th o Geological Survey for th e helpful suggestions he has m ade, also to D r. J . M. Connor for his assistance in tak in g th e p h o to ­ m icrographs.

Department o f Chemical Technology, Im perial College, S .W .l .

5th J u ly , 1939.

References.

1 “ O il S halo a n d C annol C o al,” 1938, p . x ix .

2 C. E . B e rtra n d , B u ll. Soc. In d u str. M in ., 1892, sor. 3, 6, 453-500, a n d la te r p a p ers.

3 R . H . M cK ee, “ S h ale O il.” A .C .S . M onograph, 1925.

4 H . R . J . C onacher, T ra n s. Beol. Soc. Glasgow, 1917, 16, 170.

5 K . B . B la c k b u rn a n d B . X . T em p o rly , T ra n s. R o y . Soc. E d in ., 1936, 58, 841-868.

15 IV. J . S k illing, “ O il S halo a n d C an n el C oal,” 1938, p. 32.

7 R . T hiessen, “ O rigin of th o B o g h ead C oals.” U .S. G eol. S u rv . P ro fessio n al P a p e r 1 3 2 ,1, 1925.

8 E . C. Jo ffrey . “ Coal a n d C iv iliza tio n ,” 1923, p . 45.

” A . E . F ly n n , N a tio n a l R e se arc h C ouncil of C an ad a, R e p o r t N o. 18, 1926.

13 A . R a is tric k a n d C. E . M arsh a ll, “ T ho N a tu r e a n d O rigin of Coal S eam s,” 1939 ; W . A . B o n e a n d G. W . H im u s, “ Coal, I t s C o n stitu tio n a n d U ses,” 1936.

11 T a s m a n ia n G eological S u rv ey , M in eral R esources B u lle tin , 1933, 2, N o. 8.

12 J . M. P o trio , .7. Soc. chcm. I n d ., 1905, 24, 996-1002.

13 H . P . W . G iffard, “ Oil Shalo a n d Cannol C oal,” 1938, p . 78.

O IL SH A LES AND C A N N EL COALS. 3 3 3

3 3 4 D O W N A N D H I M U S : T H E C L A S S I F I C A T I O N O F

General Definitions and Field Rela­

tions.

Principal Organic Constituents.

Principal Mineral Constituents.

Structure.

Proposed Nomenclature.

Examples, using Present Name.

Proposed Names.

Microstructurc.

Conditions of Deposition.

Proximate Composition.

Kerogcn ClayExcess Silica CaCO, MgCO, FeCO,

Approximate ratio oil yield organic residue"

T H E C LA SSIFIC A TIO N OF K E R O G E N

SHOWING THEIR INTER-RELATIONSHIPS AND KEROGEN ROCKS.

Sedimentary rocks containing organic matter which, on distillation, yields an oil, equivalent to approxi­

mately 50% of the organic content. Occur in con­

tinuous seams, covering considerable areas. Generally not associated with coal.

Spores.

Clay.

Laminated.

SPORE SHALE.

Tasmanite.

TASMANIAN SPORE SHALE.

Large numbers of llatteued spore cases, embedded in One mudstone.

Algæ.

Limestone.

Macerated plant debris.

Limestone.

Massive.

ALGAL LIMESTONE.

Kukcrsitc.

ESTl IONIAN ALGAL LIMESTONE.

Masses of algæ with shells and

silt.

Clftj".

ninatcd.

Varying amounts of plant debris, not highly compact, with a few spores, algaj and crystals of mineral matter (calcite, dolomite, pyrite, etc.) in a brownish matrix lacking

visible structure.

Fish remains.

Algæ and macerated plant debris.

Clav.

Microclastic.

ALGAL SHALE.

Ermelo Torbanite.

Stellarite.*

ERMELO ALGAL SHALE.

PIOTOU ALGAL SHALE.

Decrease in algal content.

<--- Increase in drifted constituents, i.e.

plant debris and mineral matter.

Organic matter Organic matter Organic matter accumulated partly Organic matter

mainly drifted, accumulated in in situ, partly drifted. accumulated

situ . mainly in situ.

Tasmanian Esthonian Kohat Broxburn Main Ermelo

Spore Shale.11 Algal Limestone. Kcrogen Shale. Kerogcn Shale. Algal Shale.

26 52 11*85 26-0 53-G5

27 9-25 41-95 45-2 31-3

38 5-75 8-0 8-4 11*3

Ij—Oio 20-95— 20-37-35 2-11*95 •j r 0-5 it

— — 3-5 9-0

I J

Ermelo Algal Shale.

0-G Oils obtained on carbonisation at 500° to G00° C., often contain paraffin wax (up to 10%), generally contain less than 10% of material soluble in aqueous caustic soda and have a

calorific value of over 17,000 B.Th.U.’s per pound.

Note (1). Proximate compositions in italics are calculated from data given in references 11 and 12. The remainder from analyses by the authors.

Note (2). References G to 10 are to photomicrographs of the examples cited.

O IL SH A LES AN D CAN NED COALS. 3 3 5

ROCKS AND K E R O G E N COALS.

THEIR GRADATION INTO BITUMINOUS COALS.

KEROGEN COALS.

Carbonaceous materials, in which the organic matter preponderates, occurring in lenticular patches, usually over very limited areas.

Often associated with bituminous coals, with which they may form a compound seam, or into which they may grade either laterally or vertically. The majority are of Carboniferous or Pcrmo-Carbon-

iferous age.

Algæ.

COALS.

Accumulations of fossilized plant debris, forming seams covering considerable areas, associated with relatively small amounts of mineral matter.

On distillation, yield about 10% of the organic matter as oil.

§ Ł p. s t£>

w 9

Algte and Spores and macerated macerated plant debris. plant debris.

Relatively small proportion of mineral matter.

Microclastic, exhibiting sub-conchoidal to conchoidal fracture.

ALGAL

ROCK. ALGAL

COAL.

Heterogeneous mass of decom­

posed vegetable v matter.

Single fragments of decomposed vegetable matter.

M ix tu r e .

■ Relatively small proportion of - mineral matter.

Massive. Laminated. Lenticular.

Joadja Creek Shale.7 Torbauehill

Mineral.*

JOADJA CREEK ALGAL ROCK.

TORBANEFQLL ALGAL ROCK.

Lower Dysart Cannel, Fifeshire.*

LOWER DYSART ALGAL COAL.

A mass of pale yel­

low algal colonies, so dense as to leave very little opaque

matrix.

ALGAL-SPORE COAL.

Mercer Cannel Humph Cannel, Pennsylvania.7 Lanarkshire.4

Kentucky Boghead'.8

MERCER ALGAL- IIUMPH SPORE

SPORE COAL. COAL.

KENTUCKY ALGAL- SPORE GOAL.

DURAIN.10 CL AR A IN.18 VTTRAIN.10

Banded Constituents of British Bituminous Coal.

Increase in algal content.

Increase in macerated plant debris, but not In

mineral matter.

A mixture of algse, Decrease A concentrated mass Thin bands spore cases and bit.s in algal of micro-and macro- and shreds of cuticle, embedded content. spore cases, cuticles of vitraiu in a groundmass of --->- and fragments of anddurain.

highly decomposed spores and cuticles,

plant debris. Often and resin lumps,

a greater proportion embedded in an un- of matrix than recog- resolvable mass of

nlsable constituents. macerated plant

debris.

Fish remains.

Very nearly homo­

geneous black mass.

Usually each shred is a single piece of plant debris in an advance state of decay and highly

compressed.

Organic matter accumulated in

situ.

Joadja Creek Algal Rock.1*

93 3-2 3*5 Traces,

j

Organic matter accumulated partly in situ and partly drifted.

>- Increase in proportion of drifted

material.

Vegetable debris generally accumulated in situ . Sometimes drifted.

On account of the low proportion of mineral matter, a knowledge of its proximate composition is of little significance.

Joadja Creek Lower Dysart Algal Rock. Algal Coal.

10 W

Torbanehlll Algal Rock.

5-7

Humph Spore Coal.

0*6 The ratios for a number of British bituminous coals were all of the order of 0*2.

Oils obtained by carbonisation at 500° to 600° C.

do not contain paraffin wax, generally contain upwards of 30% of material soluble in aqueous caustio soda and bave calorific values of approxi­

mately 16,000 B.Th.U.’s per pound.

3 3 6 D ISC U SSIO N ON T H E CLASSIFICA TIO N OF

D I S C U S S I O N .

C ai-t. W . H . C ad m an

(Anglo-Iranian

O il Co.) : A t th o final P le n a ry M eeting o f tlio successful first In te rn a tio n a l C onference o n Oil Shale a n d C anncl Coal, o rg an ized b y th is I n s titu te , a n d w h ic h w as hold in S co tlan d in J u n o 1938, ono o f th e S ectional R eso lu tio n s s u b m itte d a n d carried u n a n im o u sly called fo r s te p s to bo ta k e n to securo a s ta n d a rd n o m en c latu re o f th o v a rio u s oil-p ro d u cin g m ate ria ls.

I n th o d iscussion o n som o o f th o p ap o rs p re se n te d to th e Geology a n d M ining S ection, a n d also to th o R e to rtin g a n d R efin in g Section, th o u rg e n t n eed for a s ta n d a r d a n d ra tio n a l sy s te m o f n o m e n c la tu re w as rev ealed a n d w a s fre q u e n tly re m a rk e d u p o n . On m a n y occasions a tte n tio n w as d ire c te d to th e a b so lu te n e ce ssity for th e fo rm u la ­ tio n o f a s ta n d a rd iz e d a n d in te rn a tio n a l classification o f coals a n d oil shales, in ord o r to rem o v e an o m alies o n th e s u b je c t o f te rm s . C onfusion fre q u e n tly o ccu rred ow ing to th e m isap p lica tio n o f th o to rm s “ oil sh a le,” “ can n o l,” “ to rb a n ito ,” “ b o g h e ad ,” a n d

“ p a r r o t c o al,” a s u s e d b y d ifferen t m o m b crs. T hose w o rd s w ere fre q u e n tly a p p lie d in a v e ry loose m a n n e r as deso rip tiv o n am es. T h is confusion in n o m en c latu re w as n o t d u e m ere ly to th o m a n y difforent c o u n tries re p re se n te d a t th o Conference, a s i t w as also fo u n d to o x ist a m o n g s t d ifferen t re p re se n ta tiv e s o f th o sam e c o u n try . T h e a n o m a ly w as p a r tly e x p lain ed b y G. W . L oppor, w h en d iscussing W . J . S killing’s p a p e r to th o C onference o n th o “ N a tu ro o f S c o ttish C annels,” in h is re m a rk s t h a t

“ w hile, thorcforo, fro m th o p o in t o f view o f th o tec h n ica l c h em ist, c o n cern ed w ith oil p ro d u c tio n , tliero m ig h t bo a n a lm o st im p e rce p tib le g ra d u a tio n in h is ra w m ate ria l, fro m p o o r oil shalo, th ro u g h rich o r oil sh ale to loan cannels, ric h e r cannels, a n d finally to to rb a n ito , to th o geologist, oil shalos a n d can n els w cro lith o lo g ically d is tin c t.”

I n th o soction o n " O il Shalo O ccurrence a n d G eology ” in v olum o 4 o f th o “ Science o f P o tro le u m ,” i t is also p a r tly ex p la in ed b y H . R . J . C onachor, w here h e say s t h a t w hilo th o te rm “ oil shalo ” is p re cisely ap p licab lo to th o ro ck s o r th o m a te ria l w hich is w o rk ed o n a largo scale in th o L o th ia n s o f S co tlan d , “ co m m ercial p ra c tic e h a s oxpandod its m ea n in g to includo all m a n n e r o f m a te ria ls from w liich m in e ral oil can be o b ta in e d b y d istilla tio n . C on seq u en tly i t is n o w a p p lie d to a n u m b e r o f cases w hich lith o lo g ically aro n o t shalo, a n d w h ic h differ fro m th e S c o ttish ty p o also in th o n a tu ro o f th e ir o rg an ic m a tte r , a n d , co n seq u en tly , in tho c h a ra c te r o f th e oil o b ta in a b le from th e m .”

A ccording to C onachor, a re d u c tio n in th o a m o u n t o f m in e ral m a tto r o f a shalo o f th o L o th ia n ty p o re s u lts in i ts g ra d u a l c h an g e in to a to rb a n ito .

A n o th e r R e so lu tio n w h ich w as p a ssed a t th o P le n a ry M eeting w as a R e c o m m e n d a ­ tio n to tho I n s titu te o f P e tro le u m to c o n sid er th o q u estio n o f h o ld in g a sim ila r co n fer­

ence o n oil shalo a n d can n el coal w ith in th o n e x t te n y e a rs. I t is g ra tify in g to find t h a t in loss th a n tw o y e ars fro m th o d a te o f th o C onference h eld in S co tlan d , a serious e ffo rt h a s boon m ad e b y su ch e m in e n t w o rk ers in th is field a s D r. D ow n a n d D r. H im u s to estab lish a sy s te m o f u n iv e rs a l n o m e n c latu re fo r oil shales a n d cannol coals.

W h e th e r th e ir a tt e m p t w ill m e e t w ith u n iv ersal a p p ro v a l o r n o t re m a in s to bo soon.

T ho I n s titu te o f P e tro le u m in p u b lis h in g th is p a p e r is m ak in g a ste p fo rw ard to tho secu rin g o f a s ta n d a r d n o m en c latu re . T h e a u th o rs h a v e av oided, in th o ir sy s te m o f n am es, tho so w h ich hav o beon w id ely m isu sed h ith e rto , a n d in ste a d h av o em p lo y ed te rm s w h ich aro d escrip tiv o o f th o m a in c o n s titu e n ts o f th o m ate ria ls.

W h ilst m a n y m a y ag ree w ith th o a u th o rs t h a t it w o u ld bo a d v a n ta g e o u s to a v o id u sin g su ch n a m e s a s “ oil shalo,” “ cannol c o al,” e tc ., th e fa c t ro m ain s t h a t thoso n am es h a v e b eo n in local a n d genoral u se fo r so long t h a t i t is d o u b tfu l w h e th e r ev en p r o ­ h ib itio n b y a n A c t o f P a rlia m e n t w ould p re v e n t p eople from u sin g th e m , in clu d in g thoso w ho kn o w t h a t tru o oil shalo c o n ta in s no oil a s su ch , b u t o n ly p ro d u ces oil w hen tho o rg an ic m a tte r i t c o n ta in s (kerogon) is s u b je c te d to d e stru c tiv e d is tilla tio n b y h e a t, a n d tho so w ho kn o w t h a t no “ c an n e l coal ” is to -d a y bein g u se d for th o p r o ­ d u c tio n o f sm o k y lu m in o u s flam es resem b lin g th e e arly ‘ ‘ can d les ’ ’ w h en b u rn in g .

T ho a u th o r s b o ld ly p ro p o se a n e n tire ly n ew n o m e n c latu re, to bo b a se d on th e n a tu ro o f th o p la n t re m a in s a n d on th o n a tu ro o f th o m in e ral m a tte r (whoro im p o rta n t), p r e ­ fixed b y a n n d jectiv o e x p la n a to ry o f th o lo c a lity fro m w h ic h th o m a te ria l w as o b ta in e d . T h u s S c o ttish oil shalo becom es “ B ro x b u rn m a in kero g en sh ale S c o tla n d ," th o E s th o n ia n oil sh ale k u k e rsito b ecom es “ E s th o n ia n a lg a l lim e sto n e,” S o u th A frican E rm e lo to rb a n ito becom es “ E rm e lo alg al sh a lo ,” a n d so on.

O IL SHA LES AND CAN NEL COALS. 3 3 7 I t is difficult to see how th o a u th o rs w ould d isc rim in a te b e tw een “ T o rb an e h ill m in o rai ” (to rb an ito ), “ b o g h e a d ca n n e l,” a n d “ p a r r o t c o al,” in all o f w h ich th o alg al c o n te n t is hig h . I t w ill bo rom em borod t h a t th o first tw o n a m e s bocam o o f h isto ric in te re s t o n a cc o u n t o f th o co n tro v e rsy w h ic h aro se co n cern in g th o n a tu ro o f tho m a te ria ls in 1853 a n d w h ich led to a law su it.

P ro fesso r H ick lin g , w ho o x am inod a v e ry largo n u m b e r o f cannois m icroscopically, fo u n d w h a t ho te rm e d a ty p ic a l cannol to c o n sist o f “ v e ry sm all sh re d s o f v itrain -lik o m ate ria l, in la m in a r s tru c tu re , a n d to differ fro m d u ra in s b y a lm o st com ploto absonco o f a)gæ, b u t b y th o p resen ce o f sporo exinos, c u ticles a n d re sin s in som e q u a n tity .”

F ro m th is , D r. M o tt concludes t h a t i t w o u ld a p p e a r t h a t th e source o f oil fro m ty p ic a l cannois m a y bo th o resinous m a tte r p re s e n t. M r. Skilling p o in ts o u t t h a t tho m ate ria l w hich P ro fesso r H ick lin g re g ard s a s a ty p ic a l c an n el w ill n o t b u m w ith a sm o k y lu m in o u s flam e, su ch a s h a s a lw ay s boon re g ard e d a s a c h a ra c te ris tic to s t fo r a can n e l coal.

I t is to b e h o p e d t h a t th o a u th o rs w ill c a rry o u t m o re d e ta ile d w o rk in tho n e a r fu tu re o n th o lines o f th o p re s e n t p a p o r, in o rd e r to b rin g o th e r oil-yiolding m a te ria ls info th o classification th o y h a v e o u tlin e d , a n d p a rtic u la rly th o se o f Class I, w hich inclu d es th o oil san d , t a r sa n d s, a n d b itu m in o u s lim e sto n es w h ich hav o n o t boon in clu d ed in th o p a p er.

T h o y h av o dono a real se n d e e b y in clu d in g a t th o ond o f th e ir p a p o r a ta b u la te d classification o f m a n y kerogon ro ck s a n d kerogon coals, show ing th e ir in te r-rela tio n sh ip a n d tlio ir g ra d a tio n s in to b itu m in o u s coals. I n th is tab lo th o y give th e n a m e s c o m ­ m o n ly u se d a t p re s e n t, sido b y side w ith th o new n a m e s now p ro p o se d fo r th e m in th is sy sto m o f n o m en c latu re. A s th is classification gives, fo r th o first tim e , a ra tio n a l a n d scientific defin itio n o f th e p re s e n t n a m e s is th e re re a lly a n y n eed to av o id th o uso o f th es e o ld n am es, p ro v id ed th o y a re o n ly u se d a s defined b y th e a u th o rs o f th is v alu ab lo p a p o r ? S u rely th o p ro p o se d n o m en c latu re sh o u ld p re v e n t m isap p lica tio n o f th o old te rm s in fu tu re.

>

M r. J . M c C o n n e l l S a n d e r s (A sia ticP etro leu m Co.) : Scientific classification h a s boon defined 1 a s “ th o fo rm u la tio n o f a schem e o f m u tu a lly exclusive a n d co llectively e x h a u s tiv e categories, b ase d o n th o m o s t im p o r ta n t c h a ra c te ris tic s o f tho th in g s concerned, a n d th o a c tu a l re la tio n s botw oen th e m .”

F o r p ra c tic a l reaso n s th is defin itio n re q u ire s a m p lificatio n so a s to in d ic a te tho m ea n s w h e reb y th o im p o r ta n t c h a ra c te ris tic s re fe rre d to m a y b e a sc e rta in e d an d co m p ared . T h is becom es o f in creasin g im p o rta n c e w hon specific te rm s a re e m p lo y e d in th o classificato ry n o m en c latu re w h ich a re n o t se lf-ex p lan ato ry .

B efore co m m en tin g u p o n tho v e ry co m prehensive sy ste m o u tlin e d b y D ow n a n d H im u s, i t sh o u ld b e p o in te d o u t t h a t th o re so lu tio n p a ssed b y th e P le n a ry S ession o f th o Conference on Oil S hale a n d Cannol Coal in 1938 in v ite d tho In s titu to o f P e tro le u m to consider th o n o m en c la tu re o f th e v a rio u s oil-p ro d u cin g m a te ria ls discu ssed o r doscribed in th o v a rio u s p a p e rs s u b m itte d to tho C onference.

W ith th o e x cep tio n o f cannol, no v a rie tie s o f coal e n te re d in to th o d e lib e ra tio n s o f th o C onference, lionco th o ex te n sio n o f th e n o w p ro p o sed schom e so a s to in clu d e tho classification o f coals o f th e p e a t- a n th r a c ite series is so m e w h at o u tsid e th e scopo o f th o original in v ita tio n .

M oreover, th o classification o f coals h a s a lre a d y boon th o s u b je c t o f c o n sid era tio n b y o th e r I n te r n a tio n a l C onferences, a n d a cc o rd in g to R e d m a y n o 2 th o b e s t o f theso classifications w as t h a t a d o p te d b y th o I n te rn a tio n a l G eological C ongress h e ld a t T o ro n to in 1913.

U n d e r th is schem e coals w ore d iv id e d in to fo u r m a in classes a n d throo sub-classes, a n d it in clu d ed n o t o n ly can n el, b u t also lignito a n d b ro w n coal. I t is n o t p ro p o sed to d iscuss th o m e rits o r d e m e rits o f th o T o ro n to schem o, th e b a sis o f classification boing e n tire ly différent fro m t h a t p ro p o sed b y D ow n a n d H im u s.

N evertholoss, th o su g g estio n b y th o l a tte r t h a t th o classificatio n o f oil-yielding m a te ria ls sh o u ld co m p re h en d coals w h ic h u n d e r c e rta in c o n d itio n s m a y bo said to also y ield oils is e n tire ly ra tio n a l, a n d w o rth y o f c arefu l c o n sid eratio n .

A s is well kn o w n , lo w -to m p o ratu ro coal ta rs , a n d especially v a c u u m ta rs , c o n ta in c o n s titu e n ts w h ich a re id e n tic a l w ith su b s ta n c es fo u n d in p e tro le u m , a n d w h ereas a h ig h -te m p e r a tu r e t a r is m a in ly a ro m a tic in c lia ra e te r, a lo w -tem p cra tu re one is paraffinoid.

I t is th erefo re n ecessary to closely define th o c o n d itio n s u n d e r w hich oil is p ro d u c ed

3 3 8 D ISC U SSIO N ON T H E CLASSIFICA TIO N OF

b y h e a t tr e a tm e n t if, as p ro p o sed b y D ow n a n d H im u s, th e ir C lass I I (oil shales) aro to b e defined a s “ su b s ta n c e s w h ic h yield 50 p e r cen t, o r inoro o f th o ir o rg an ic m a tte r as o il,’’ a n d a re th u s to bo d istin g u ish e d fro m C lass I I I m a te ria ls w h ich yield only 16 p e r c en t, a s oil.

I t is tru o t h a t theso defin itio n s a re ta k e n in c o n ju n c tio n w ith th e re la tiv o solu b ility o f th e o rg an ic m a tte r in “ n o rm a l so lv o n ts fo r p o tro le u m ,” b u t th o l a t t e r expression is so m e w h a t am b ig u o u s, b o th a s re g ard s th e n a tu ro o f p erm issib le so lv e n ts a n d th e c o n d itio n s o f e x tra c tio n . A s w ill bo n o te d late r, h e a t tr e a tm e n t o f th o m a te ria l before a p p lic a tio n o f a so lv e n t m ig h t bo considered a leg itim a te m o th o d o f a sc ertain in g th e n a tu ro o f th o organic m a tte r prosont.

T horo w ould a p p ea r, h ow ever, little difficulty in se ttlin g th ese d e ta ils o f p ra c tic a l p ro ced u re a n d a d o p tin g th o p rim a ry classification in to tlireo m ain classes. A s reg ard s n o m en c latu re, it is n o te d t h a t i t is p ro p o sed to a b a n d o n th o n a m e s “ o il shalo ” a n d

“ cannol co al,” th o first o n th e g ro u n d t h a t i t is m isleading, a n d th o second b e cau se it gives n o in d ic a tio n o f th o n a tu ro o f th e m ate ria l.

O n th o o th e r h a n d , b o th theso to rm s aro v e ry firm ly estab lish e d , a n d it w o u ld bo difficult to rep lace th e m ; n e ith e r sh o u ld i t bo n ecessary if th o ir m isu se co u ld bo ob%'iatod b y a m o re prociso defin itio n o f th e ir ow n m ea n in g o r t h a t o f th o te rm s to w h ich th e y aro fre q u e n tly m isap p lied .

O il shalo is p e rfe c tly well u n d e rsto o d b y tec h n o lo g ists to m ea n “ a shalo cap ab lo o f y ield in g oil ” a n d i t is no m o re m isle ad in g th a n su c h te rm s a s “ oil seed ,” “ oil c a k e ,”

a n d “ o ilsto n o ,” in w h ic h th reo d is tin c t m ean in g s aro a tta c h e d to th o w o rd “ o i l ” a n d o n ly ono o f th o su b s ta n c es co n cern ed is u n d e rsto o d to c o n ta in oil as such.

A gain, i t m ig h t bo c o n te n d e d t h a t th o t e r m “ can n o l,” i f its d e riv a tio n fro m “ c a n d le ” is acc ep te d , does in fa c t in d ic a to th o n a tu ro o f th o m ate ria l, o r a t le a st ono o f i ts p ro p e rties. A p a rt fro m th is , c an n cl com es u n d e r Class C o f th o T o ro n to classification o f coals, a n d th u s e arn s tho r ig h t to re ta in i ts placo a m o n g s t tech n o lo g ical term s.

A c tu ally th o ro is a v a s t n u m b e r o f a c c ep te d te rm s in tech n o lo g y w h ich givo no in d ic a tio n o f th o n a tu ro o f th o m a te ria l to w hich th e y aro a p p lied , a n d y e t a re useful a n d co n v en ien t os ty p o d esig n atio n s in a elassificatory schem e.

I t is su g g ested t h a t th o p ro p o sed a lte rn a tiv e to rm s “ kcrogen ro c k ” a n d “ kerogen coal ” sh o u ld p ro fo rab ly bo o m ploycd in th e a d je c tiv a l form , since kerogon is a s u b ­ s ta n tiv e ; a n d t h a t th o p rim a ry classification sh o u ld bo m odified so a s to a d a p t its e lf to th o classificatio n o f se d im e n ta ry re e k s sug g ested b y H . B . M ilner.3

T h u s th o la tto r ’s m a in g ro u p “ B ” (R ocks o f o rg an ic origin) co u ld h av o its fo u rth sub-d iv isio n “ B 4 ” (C arbonaceous rocks) ch an g ed a s follow s :—

B,.

11,1.

Bituminous Rocks.

ltocka yielding oil or tar by destructive distillation.

C haracter.

Arenaccou-s Calcareous Argillaceous Aspiialtic

B,2.

Kerogenous Rocks.

T y p e . Oil sands Tar sands Bituminous

limestone Oil-bearing

shales Native asphalts Gilsonite

Character.

Calcareous Argillaceous Calcsreo-

argillaccous Sapropelic

B,3.

Carbonaceous Rocks.

T y p e.

lvukersite Scottish oil

shales Tasmanltc Koliat oU shale Torbanltcs Bogheads

Character.

Anthracitic

T y p e . Anthracite and

semi-anthra­

“ Bituminous” Bituminous cite Kerogenous Canncl coal coal

Lignitic Lignite

Brown coal Sub-lignltlc Peat

T h e p ra c tic a l a p p lic a tio n o f th is schom o a s a p re lim in a ry so rtin g to s t does n o t re q u ire a v e ry e la b o ra te p ro ced u re. A ll tho se d im e n ta ry ro ck s c o n sid ered y ield oil o r t a r b y d is tilla tio n ; th o se in G roup B , 1 aro d istin g u ish e d fro m th o se in th o o th e r tw o g ro u p s b y th o g re a te r so lu b ility o f th e ir organic m a tto r os p ro p o se d b y D o w n a n d H im u s.

G roup B j2 differs from B ,3 in t h a t c a rb o n iza tio n o r “ co alification ” h a s a d v a n c e d to a g re a te r dogrco in th e la tte r. T h u s b lac k cannol is co n sid ered a s a kerogenous coal, w h ereas th o lig h ter-co lo u red ty p e s o f c an n e l w h ic h m a y c o n ta in a re la tiv e ly larg e r p ro p o rtio n o f p re serv e d o rg an ic re m a in s (kerogon) a re con sid ered a s Sapropelic kerogenous rocks.

T h e seco n d ary classification p ro p o se d b y D ow n a n d H im u s is b a s e d o n th e a s s u m p ­ tio n t h a t th o o rg an ic re m a in s, w h ic h c o n s titu te th o kero g en in som o o f th o se oil- a n d tar-y ie ld in g m in erals, c an be re a d ily a n d d efin itely id en tified a s e ith e r alga; o r spores.

OIL SH A LES AN D C A N N EL COALS. 3 3 9 I t is tru o t h a t th o w o rk o f B la c k b u rn a n d T cm p erlo y h a s show n m o s t co n v in cin g ly t h a t th o “ yellow b o d ies ” in a n u m b e r o f cannols a n d b o g h e ad s a re th o re m a in s o f a n a lg a v e ry sim ila r to th o liv in g Bolryococcus B r a u n ii, b u t th o p o sitio n re g a rd in g th o id en tificatio n o f o th e r o rg an ic m a tte r a s spores is n o t so c le ar c u t.

As p o in te d o u t b y S to p es a n d W h eeler,4 a g ro u p o f c rushod, sem i-d ecay ed , o r b acteria -in v a d o d sporos m ay sim u la to o th e r p la n t ro m ain s o r algas o f v a rio u s s o r ts .' I t is also possible, especially in th o caso o f m icrospores, t h a t th ic k -w a lle d re s tin g spores o f algjo aro alono preserv ed , o r p a r tly so, in w h ic h case th e m a te ria l c o n ta in in g th e m sh o u ld rig h tly bo d e sig n ated a s ‘ ‘ alg a l.’ ’

T h ere is a fu rth e r o b jectio n to th e u se o f th e te rm “ alg al ” w h e n a p p lie d in c o n ­ n ectio n w ith se d im o n to ry ro ck s, in t h a t i t is liable to bo co nfused w ith th o sam e te rm a s co m m o n ly e m p lo y ed to d e sig n ate ro ck s, b u ilt u p o f o r c o n ta in in g fossilized o r m in eralized algae

T h u s D ow n a n d H im u s use th o to rm “ alg al lim esto n e ” to classify ro c k s o f th o E s th o n ia n ICukorsito ty p o , b u t a m o n g p e tro g ra p h o rs th o to rm is u se d to classify lim e ­ sto n e s w h ich c o n ta in o r aro m ad o u p o f th o re m a in s o f su c h algse a s L ithotham nion o r Chara.

E v e n th o m ore g en eral to rm “ algal ro c k ” m ig h t bo c riticize d fro m th is viow point, for, acco rd in g to S o lm s-L au b a e h ,5 u n d o u b te d Liihotham nicc a re a b u n d a n t th ro u g h o u t th o series o f T e r tia r y d ep o sits, a n d in som e localities form a lm o s t th o e n tire m a te ria l o f th ic k la y e rs ; th o y com pose th o g ran ito -m arb lo o f th o N u m m u litic rocks.

T ho q u estio n arises w lieth o r i t is n e ce ssa ry o r desirablo to a tt e m p t su c h a fino d istin c tio n botw eon algae a n d sporos a s b ein g re sp ec tiv e ly in d ic a tiv e o f d is tin c t ty p e s o f kerogon. T ho p a s t h is to ry o f in v estig a tio n s re la tin g to th e la tte r show s only to o c learly t h a t th o p ra c tic a l id en tific atio n o f tho ‘ * yollow b odies ’ ’ h as b e en a m a tte r o f su ch d ifficulty t h a t ovon oxpcrioncod o b se rv ers h a v e b e e n c o n te n t to a d o p t C rum B ro w n ’s in d efin ite te r m , o r so m o th in g e q u ally n o n c o m m itta l.

S o m etim es bodios o f sporo-liko ap p o aran co h a v e b e en d oscribed a s rosins, th o d esc rip tio n bein g su b s e q u e n tly a b a n d o n e d o n th o g ro u n d t h a t th o y w ore insolublo in th o u su a l rcsin -so lv en ts. A lth o u g h in som o cases th o a c tu a l o rg an ized re m a in s havo b een id en tified a s sporos o r algae, i t is w o rth y o f n o to t h a t rosin o u s m a tte r m ig h t w ell h av o b een p re se n t, sinco sovcral fossil re sin s aro k n o w n to bo insolublo u n til th e y hav o b een h e a t-tre a te d , a n d it is a w ell-know n fa c t t h a t th o a m o u n t o f o rg an ic m a t t e r r e ­ m o v ab le b y so lv o n ts fro m kerogenous m a te ria l is in cre ased b y h e a t tr e a tm e n t.

E n g lo r 8 s ta te s t h a t c e rta in in soluble “ b i tu m e n s ” becom o solublo a f te r h e a tin g ; V ignon 7 show ed t h a t th o a m o u n t o x tra c tc d fro m coal b y tr e a tm e n t w ith p y rid in e , an ilin e, a n d quinolino in creased in th o sam o o rd e r a s th o increaso in b o iling p o in t o f th o so lv e n t, w h ilst M cKoo a n d L y d o r 8 h o ld th e view t h a t tho d e co m p o sitio n o f kerogon b y heat, to fo rm oil ta k e s placo in tw o stag es, th e in so lu b le kerogon b e in g first c o n ­ v e rte d in to a solublo fo rm w hich is u n s ta b le to w a rd s h e a t, th is on f u r th e r h e a tin g g iv in g oil o f th o p o tro lo u m ty p o o f h ig h er s a tu r a tio n a n d g re a te r s ta b ility .

T ho p re s e n t w rite r h a s fo u n d rosin d ro p lets, in th e insolublo form , p re s e n t in sovcral v a rie tie s o f crudo p e tro leu m , a n d o fte n a cc o m p a n ied b y spore cases, p a r tly decom posed p la n t d eb ris, a n d algal ro m ain s. S o m etim es th o ro h av o boon fo u n d in th o sam o crude oil fra g m e n ts o f w oody tissu e in w h ic h th e cells lin in g schizogenous resin ca v itie s w ere p e rfe c tly p reserv ed , w h ilst re sin w as fo u n d d issolved in th o oil.

R esin o u s m a tte r in coals, cannols, a n d lignites h a s boon th e s u b je c t o f o x tonsive in v estig a tio n , a n d i t a p p e a rs to bo tho co n sen su s o f o p in io n t h a t resin, w axes, a n d h ig h er f a tt y acid s h av o exorcised som e k in d o f p ro te c tiv e fu n c tio n in p re serv in g th e cuticles, spore cases, p o llen oxinos, b a rk , a n d c o rk w h ich a re fo u n d in c arb o n aceo u s rocks.

T hose co n sid eratio n s seem to p o in t th o w a y to th o conclusion t h a t th o re al kerogon—

th e oil-form er— does n o t e n tire ly resido in th o c u tic u la r sk eleto n s o f alga;, th o o u te r co atin g s o f spores, o r th o relics o f p la n t tissu e , a lth o u g h th o se o rg an ic re m a in s m a y c o n trib u te to th o co m p o sitio n o f th e oil o r t a r p ro d u c ed b y d istillatio n .

I n fa c t, a s a b asis fo r classification, i t w o u ld a p p e a r t h a t sp o res a n d algio, o r a n y o th e r e m b a lm e d organic rem a in s, a re n o t m u tu a lly exclusivo n o r collectiv ely e x h a u s tiv e d esig n atio n s : th o y re p re se n t o n ly tho s y m p to m s o f tho oil-yielding p ro p e n s ity in tho m a te ria ls concerned, n o t th e ir p rim a ry cause.

I n a p p a re n t o p p o sitio n to th is o p inion, B la c k b u rn a n d T em p erle y ,8 a s a re s u lt o f e x p erim e n ts o n re ce n t, d rie d coorongite, show ed t h a t w h ilst oily a n d w a x y m a te ria l co u ld bo e x tra c te d b y so lv en ts, th o re la tiv e ly insolublo resid u e co u ld b e p re su m e d to bo cap ab le o f y ield in g “ p araffin p ro d u c ts ” b y d e stru c tiv e d istilla tio n .

3 4 0 D ISCU SSIO N ON T H E CLA SSIFICA TIO N O F

T h o y also rofor to th e fa c t t h a t cannois m a y o r m a y n o t c o n ta in “ yellow b o d ies ,”

b u t w h en those do fo rm a largo p ro p o rtio n o f th o coal i t becom es m o re v a lu a b le a s a source o f “ p araffin ” t h a n o f gas.

Thoro a p p e a rs to bo a n im p lied d istin c tio n b etw een “ p araffin ” d e riv e d fro m cannol coal a n d “ paraffin p ro d u c ts ” fro m re c e n t coorongite, th e l a t t e r p re s u m a b ly referrin g to a n y m em b ers o f th o p araffin series fro m m e th a n e u p w a rd s, th o fo rm er to th o w a x w hich c a n bo o b ta in e d b y re -ru n n in g th o c ru d e d istilla te a n d chilling th o pressiblo

“ c u t.”

I n e ith e r case th eso a u th o rs w ould seem to fa v o u r th o h y p o th es is t h a t oil is d eriv ed fro m th e alg al sk eleto n s ra th e r th a n fro m th o m a tr ix w hich s u rro u n d s th e m in th o m in eral. W h ils t i t is tru e , a s show n b y L egg a n d W hcolor,10 t h a t a m o d e m cutielo (A gave am cricana) gave a b o u t GO p e r c en t, o f v a cu u m t a r c o n ta in in g h y d ro c a rb o n s, a n d fossil cuticlo fro m R u ss ia n p a p o r coal g av e a b o u t 20 p e r c en t, loss, th o fo rm er w as easily a tta c k e d b y alk ali, th o la tte r o n ly slig h tly , a n d th u s , w hile a c c o u n tin g fo r tho fo rm atio n o f h y d ro c arb o n s b y th o d e stru c tiv e d is tillatio n o f c u tin a n d acco m p a n y in g f a tt y a cid s a n d w axes, tho ex iste n ce o f su lp h u r a n d n itro g e n c o m p o u n d s in th o r e su ltin g oil is n o t oxplained.

I f orig in al coll c o n te n ts aro assu m e d to acc o m p a n y th o alg al sko leto n o r sp o re c o a ts in th o korogen, th e n n o t o n ly su lp h u r a n d n itro g e n , b u t p e rh a p s tho p h o sp h o ru s w h ic h is fo u n d in th o a s h c an bo a c c o u n te d for.

I n th is con n ectio n i t is in te re s tin g to n o te th o an aly sis o f B a lk a sh S apropolito (p resu m ab ly Botryococcus) g iv en b y Z elin sk y .11

T ho la tte r s ta te s t h a t 39 p e r c en t, o f tho m a te ria l is soluble in carb o n te tra c h lo rid e , th o o x tra c t c o n ta in in g frco f a tt y a cid s a n d th e ir esters. T ho o rg an ic m a tte r is s ta te d to h av o th o follow ing com p o sitio n :—

%

C arbon . . . 73-7G

H y d ro g e n . . . 10-01

S u l p h u r . . . . . . . . 1 - 0 3

N itro g en . . . 0-56

P h o s p h o ru s . . . traco

O xygen . . . 13-74

I n th e case o f T a s m a n ia n oil shale, K u r t h a n d R o g ers 12 s ta to t h a t n e a rly , b u t n o t q u ite all th o oil y ield is p ro d u c e d fro m th o am bor-liko bodies, w h ic h th o y su g g est aro n o t sporo cases, b u t th o spores th e m se lv es fossilized. T h e y f u r th e r s ta to t h a t tho shalo, freed fro m sp o re cases, p ro d u c es som o oil, b u t t h a t th o gas p ro d u c o d d u rin g d istilla tio n is free fro m h y d ro g e n su lp h id e. T ho e n tire shalo is show n to y ield b o th a m m o n ia a n d su lp h u r co m p o u n d s.

I n view , th e n , o f th e d ifficulty in e sta b lish in g th o id e n tity o f th e “ y ellow b o d ies ” in all cases, a n d b ecau se i t is n o t y e t e stab lish e d t h a t korogen is e x clu siv ely re p re se n te d b y algæ a n d /o r spores, i t is su g g ested t h a t th o l a tte r te rm s aro n o t e n tire ly s a tis fa c to ry fo r p u rp o se s o f classification.

F o r p ra c tic a l p u rp o se s th e re is m u c h to b e sa id fo r a n o m en c latu re w h ic h is self- suggestivo o f p ro p e rtie s w h ic h a re re a d ily d iscem ib lo o r e asily a sc ertain a b lo . M an y o f th o d e sc rip tiv e te rm s a lre a d y com m o n ly e m p lo y e d in th o in d u s try aro o f th is n a tu r e , b u t confusion h a s a risen becau se m a te ria ls h a v in g a single, o r a t b e s t a few, p h y sic a l p ro p e rtie s in co m m o n h a v e b e en d e sig n ate d b y th o sam e te rm .

S o m etim es tho m is a p p lica tio n h a s been in re sp e c t to tho m in e ral co m p o n e n t o f tho m a te ria l, w h ilst in o th e rs i t is th e organic a ttr ib u te w h ic h h a s b e en w ro n g ly d e sig n ated .

I t w as su g g ested b y M aegregor 13 t h a t th o n o m e n c la tu re sh o u ld ta k o in to a cc o u n t su ch fa cto rs a s a p p ea ran c e, s tru c tu re , oil-yicld, a n d a sh c o n te n t, w h ils t R o b e rts 11 affirm s t h a t if a n y a tt e m p t w ore m a d e to sim p lify th o n o m en c latu re o f can n els, a tt e n ­ tio n sh o u ld also bo giv en to th e ir coking pro p en sities.

I t m a y b e su g g ested f u rth e r t h a t in g a th e rin g m a te ria l fo r th e p u rp o so o f classifica­

tio n m o re a tte n tio n sh o u ld bo g iv en to th o p o ssib ilities o f th e m in e ra ls w h ic h a cc o m p a n y th o kerogenous m ate ria ls , a n d w h ich m a y bo recognized b y p é tro g ra p h ie m e th o d s o r d e te c te d b y chem ical an aly sis.

A m o n g st th e la tte r, c e rta in elem en ts, su c h a s v a n a d iu m , nickel, a n d to som o e x te n t a lu m in iu m a n d m ag n esiu m , m ay h av e a special significance in re la tio n to th e o rg an ic c o n s titu e n ts o f th e m a te ria l.

F o r in stan co , T a s m a n ito c o n ta in s as korogen, bodies w h ich a re su p p o sed to bo th e

O IL SHA LES AND CAN NEL COALS. 3 4 1 p re serv e d spores o f ly co p o d iu m . Since th o Lycopodineas, a rc q u ite re m a rk a b le fo r th e ir h ig h a lu m in iu m c o n te n t, a n d since th o spores aro largo a n d easily s o p a rn tc d from th o m in e ra l m a trix , th e e stim a tio n o f a lu m in iu m in th e ir a sh w ould a p p e a r to h a v e m o re vuluo th a n th o an aly sis o f tho b u lk m inoral.

References to contribution o f M r . M cC onnell Sanders.

I W olf, A b ra h a m , “ E n c y c lo p e d ia B rita n n ic a ,” 1 4 th E d itio n , V ol. 5, p . 778.

3 R e d m a y n e, S ir R . S., ibid., “ Coal a n d coal m in in g ,” p p . 868-903.

3 M ilner, H . B ., “ S e d im e n ta ry P e tro g ra p h y ,” 1929.

4 S topos, M. C., a n d W heeler, R . V ., “ T h o C o n s titu tio n of C oal,” D .S .I.R . M o n o g rap h , 1918.

6 S olm s-L au b aeh , H . G raf 7.u, “ E o ssil B o ta n y ,” E n g lish tra n s la tio n , 1891.

6 E n g lo r, C „ D a s E rdol, 1917, 1, 35.

7 V ignon, L ., C om pt. rend., 1914, 158, 1421.

8 M cKeo, R . H ., a n d L ydor, E . E ., J . I n d . E n g . C hem ., 1921,

13,

613 cl seq.

0 B la c k b u rn ,,K . B ., a n d T om perley, B . N ., T ra n s. R o y . Soc. E d in ., 1936, 58, 841-S68.

10 Logg, V. H ., a n d W hcoler, R . V ., “ S a fe ty in M ines,” R e s. B d . .P ap er N o. 17, 1926, a n d J . chem. Soc., 1925,

127,

1412.

II Z elinski, N . I)., Brennsl.-C hc/nie, 1925,

6,

36 5 -3 6 9 ; 1926,

7,

35-37.

12 K u r th , E . E ., a n d R ogers, L. J . , “ O il S hale a n d C annol C oal,” 1938, p p . 193-209.

13 M acgrogor, M ., ib id ., p p . 8-17.

14 R o b e rts , J . , ib id ., p . 39.

D it. M. M a c g r e g o r (Geological Survey) : In a p a p o r c o m m u n ica te d to th o C on­

ference on O il Shale a n d C annel Coal h o ld a t G lasgow in 1938 I em p h asized th o d e s ir­

a b ility o f securing, if possible, a s ta n d a r d n o m en c la tu re for th o v a rio u s oil-yielding m a te ria ls in clu d e d u n d e r th o d e sig n atio n s can n el, b o g h e ad , e tc . I h a d in m in d tho d ifficulty e x p erien ced b y th o fiold w o rk er in tho lac k o f a n y s ta n d a r d series o f categ o ries to w hich to refer, a n d th o fa c t t h a t te r m s su ch a s oil shalo a n d can n el w ere u se d fo r m a te ria ls differing w idely in m odo o f occurrence, origin, a n d co m p o sitio n . T h u s th o te rm oil shalo, long e m p lo y ed in S co tla n d in co n n ectio n w ith th e L ow er C arb o n ifero u s sh ales o f th o L o th ia n s, h as b e en u se d to d esig n ate oil-yielding m a te ria ls o f m a n y d ifferen t k in d s a n d ages. I t h a s b e en used , fo r e x am p le, fo r th o to rb a n ite s a n d cannois o f Now S o u th W ales (P erm o-C arboniforous) ; for th o sp o re-rich “ ta s m a n ito ” o f th e M ersoy R iv e r V alley in T as m a n ia, re g ard e d a s a sh a llo w -w ater m arin e se d im e n t p ro b a b ly o f P erm o -C arb o n ifo ro u s a g e ; for th e E sto n ia n “ k u k e rs ite ,” a m arin o d e p o sit o f O rdovician a g o ; fo r th o “ m a ra h u ito ” o f B a h ia in B razil, a so m e w h a t v ariab lo m a te ria l o f alg al origin, allied to to rb a n ito (C retaceous o r E a rly E ocene) ; fo r th o b la c k c arb o n aceo u s shales o f th o E a s te rn U n ite d S ta te s (D ovonian) ; a n d for o th e r d e p o sits o f v a ry in g c h a ra c te r in d ifferen t c o u n tries. T ho te r m cannol, a g ain , includes m a te ria ls o f d iffere n t c o m p o sitio n a n d w idely d ifferen t econom ic v alu e. I n p u ttin g fo rw ard m y sug g estio n I e n v isag ed th o a p p o in tm e n t o f a sm a ll co m m itte e to o xam ine a n d re p o rt u p o n th o qu estio n , ju s t a s th e B ritis h A ssociation C om m ittee on p é tro g ra p h ie classification a p p o in te d in 1932 o x am in ed a n d re p o rte d on th o n o m en c la ­ tu r e o f igneous rocks. T ho a u th o rs o f tho p a p e r now p re s e n te d h av o b o ld ly ta c k led tho p ro b lem o f b o th th o n o m en c latu re a n d th o classification o f th e n a tu r a lly o ccu rrin g oil-yiolding m ate ria ls. T h e ir n o m en c latu re is b a se d o n th e d o m in a n t p la n t a n d m in o ral c o n s titu e n ts p re so n t a n d th e classification is p u t fo rw a rd m erely a s “ a fo u n d a ­ tio n o n w h ich fu rth e r classifications c a n b o doveloped a s o u r know ledge o f th o c h e m istry o f th ese m a te ria ls in creases.” I t is v ery d o u b tfu l, h ow ever, if th o p ro p o sed n o m e n ­ c la tu re w ill be acc ep ta b le to thoso w ho h a v e to d eal w ith th o ra w m a te ria ls in th e field a n d lab o ra to ry . T h e in tro d u c tio n o f su c h te rm s a s “ korogen ro ck s ” a n d “ kerogen coals ” a p p e a rs superfluous. N o r does i t scom in th o lea st n ecessary to d isc o n tin u e th o u se o f su ch lo n g -estab lish ed n a m e s a s oil-shalo a n d cannel. I t sh o u ld bo q u ite possible to re ta in thoso n a m e s fo r defin ite g ro u p s o f oil-yiolding m ate ria ls , a n d to su b d iv id e thoso f u rth e r a cco rd in g to th e ir esse n tia l m acroscopic a n d m icroscopic c lia ra c te rs.

C annels a re m ic ro -frag m e n ta l coals a n d fo rm a g ra d ed series ra n g in g fro m th o rich ly alg al b row n a n d b la c k bogheads, th ro u g h alg al-sp o re can n els w ith in cre asin g p ro p o r­

tio n s o f d ecom posed p la n t d e b ris fo rm in g a b rig h t tra n s p a r e n t groundm asB , to c anneloid sh ales c o n ta in in g a h ig h p ro p o rtio n o f in organic m a tte r . I t sh o u ld bo q u ito possible to define th o series b ro w n b oghead, b la c k b o ghead, b o g h ead -ean n el, can n el, can n elo id shalo n o t o n ly in te rm s o f d e cre asin g oil-yield, b u t also in te rm s o f m acroscopic a n d