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Sedimentary Facies Terminology John C

Sedimentary Facies Terminology John C

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Undergraduate Theses and Senior Projects Theses, Dissertations, and Senior Projects

1955 Sedimentary Terminology John C. Redmond

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SEDIMENTARY FACIES TERMINOLOGY

by

.Jolm c. Redmond TABLE OF CONTENTS

Introduction Page 1 Glos:sairy of Sedimentary Facies Terminology . 3

Ji1acies_i 3

Lithotope 7

Lithofacies 7

Biofaicies 8

Biotope 9

Physiofacies 9

Tectotope 9 Tectofacies 10

Magnafacies 11

Parvafa:cies 11

Explaination 12; Original Interpr~tations 13

Bibliography 20 1 .

INTRODUCTION

There exists at the present time , in the

field of , a confusion pretaining

to facies terminology. Some sedimentologists tend

to reduce the seriousne ss of the s i tuation such

as Griffiths , who states , " the problem of

facies is initially one of semantics , and t he

absence of agreement regarding the existing alternative definitions of the term r eflects both t he vague nature of the problem and a

lack of understanding which prevents any logical approach. " There is a reason for this confusion however , and it is a p tly stated as originating by t h e t i ghtening up of t h e facies terminology due to the growing realization of the i mportance of facies analysis in a number of geological fields . As proof of this the nature of the Alpine stru ctures and of complex structures of other regions were solved u sing the concept of facies

(Mu ller, 1949 , p . 49 ).

Another , and perhaps as imp ortant , a reason falls directly on those person~ who propose the 2 .

terminology themselves ; who do not practice what

they preach. One author was noted (Caster , 1934,

p . 10) who spent two pages to explain his term for

a phase of facies , then on the next page used

a diff erent term in his article . _

The writer does not believe however , t hat

Griffith is corvect in calling the confusion

a ma tter of semantics . Besides the aforemen­

tioned reasons f or confusion there seems to be

a glaring fault that stands out as t h e main

cause of confusion . That is the inapp licability

of t h e terms p roposed by one sedimentologist e in a specified area to fit the needs and structure

of another sedimentologist in a different area .

This incompatibility among sedimentolog ists also

is t h e reason for t h e variety of facies t 0rms

that a r e now present , and if the present trend

of orig inating n ew terms by each sedimentolog ist

instead of applying those definitions alreads ~ f) . on h and continue s , t he interpitation of facies

will become worthle ss in the literature f or t h e

fact that one will not be able to understand

what idea the writer is trying to conv ey. 3 .

GLOSSARY OF SEDIMENTARY FACIES TERMINOLOGY

Facies - The original recognition of sedi­ mentary facies is credited to Gressly and

Prevost (1938) based on lithologic chang es in the Jurassic rocks of Eastern France . In this case they are refering to the difference in types .

Through t h e years sedimentary facies has come to mean the combined products of past conditions , processes , and events as recorded over some fraction of the earth's surface and representing some fraction of g eological history (Moore , 1949 , p . 5) . An example of the formation of facies is given in Plate I .

Facies has also been used in t h e stratigraphic unrestricted sense , such as ; the red bed facies , which comprises all of the , or the black facies , which comp rises all of t h e black s hales known . Moore , in his same article, states that in t h is sense , facies is a term app licable to every distinguishable sedimentary record of a depositional envi ronment . However 4 .

PLATE I

The formation of facies on a coral island e (Moore , 1949 , p . 3) .

-- - .fac-- 1~ -

"cr0 :fq c,~.Po"'t .... . ' --~=.= ..... ·~...... •: - -- ...... • . 5 .

he further brings out that if we accept this

definition we must accept the following

conclusions : 1 . 'the word 11 faciesn· covers

t h e lithologic - biologic significance of every

observed ; 2 . facies follow

one another in ·. vertical s 3quence everywhere;

3 . most s edimentary formations compr ise several facies , which occur in sequence or are inter­ bedded; and 4 . unless we emp loy the same word

in div er gent manner , use of 11 I'acies 11 in t h is

sense l eaves us without a term for areally

segregate d parts of strati g raphic units in wh ich one or several different types of rocks furnish expression of g eog raphic variation in (Moore , 1949 , p . 7 ).

F~cies is also used in referring to a homogeneous unit of• sedimentary rock s that h as characteristics differentiating it from other rock units . It is also used in refering to a faunal or floral ass ociation which normally is t he result of t he type of bottom or other ecological factors

(McKee , 1949 , p . 36) . 6 .

There is the definition of facies which includes t he lithologic and biologic variations of differing strata and implies an environmentally controlled separation (Sp ieker, 1949 , p . 55) . Facies chang es based on either the rock variations or the faunal variation , whichever is t h e mos t obvious is u sed by Wood (1949 , p . 154} . Facies is also used in connection with the areas of differing deposition (see Fig . l} , such as continent al facies and ncritic facies (Lowman, 1949 , P • 125) .

North South Up dip Down dip

CONTINENTAL F'AC JES Upper Cat0Jhoula

Lowe~ Cataho.'ula

e Figure 1 (Lowman , 1949 ) 7 .

Facies are simpiy the lateral lithologic

variations, crea-ted essentially within the same

time limits, and are g iven geographic names 1 (Stockdale , 1949, · ) •

Lithotope - A lithotope includes all

of the enviromentally significant characteristics

of a sedimentary deposit ; characteristics from

which the environmental conditions may be

· interpreted (Wells, 1947 , p . 120) .

Lithofacies - Lithofacies denotes the

collective characters of any sedimentary rock

which furnish record of its depositional

environment (Moore , 1949 , p . 13) . The above

definition, in its broadest possible sense,

applies to sedimentary deposits without refrence

to how they are classified stratigraphically.

Another slightly different definition for

lithofacies states that it is each change in

rock type encountered laterally within a formation

(McKee , 1949 , p . 35) . It is also described

as the sum total of the lithological character­

istics of a sedimentary rock. (Krumbein, 1948 ,

P • 1909) . Lithofacies are groups of strata - 8 . e different in litholog ic aspec t from later ally

~quivalent rock s ( see Fig . 2 ), t h e aspect

being controlle d by t h e litLotope or a

c ombination of lith otop es . Thus lith ofac ies is

being derived from t h e t otal aspec t of t h e lith o­

l ogy (Sloss et . al., 1949 , p . 1924).

EXAMPLE OF: LITHO FACIE-S INTREPRETAT(Oij · qu.ar-11. ~.incl f•cie..s

. . .. . ' . .. , ·.. - . . . " . " .· -. ---~------=- :::::. ------~- --===--- :::::::-- --=---=------:::::: -

F i gure 2,

Biofacies - Biofa c i es designate s collectively

t he s trictly org anic elements of a pa r ticular

sed i mentary depos i t (Lowman , 194.6 , pl25 ).

Biofacie s ma y also be d efined as t h e compo sition

one or more biotopes differi n g in biologic

aspec t from laterally equi valent biolog ic : 9 .

assemblages. The biofacies is shown in figure 3 .

CENTRAL K N. S. KAN. N.OKLA.

-Fusu.linid facies fusulinid-OHonosia fades ---i•,

~R-oJtd,ils ~ ~ \'..?jJ,'~tonosi« 61Qp Crmo/J Stems (IJ -~ r

Figure 3 (Moore , 1949)

Biotope - A biotope is defined as an

area in which the ecologic conditions , and

organisms related to those ecological conditions ,

are uniform (Heese, Allen , & Schmidt , 1 937 , p . 33.~ ,.

Physiofacies - Physiofacies signifies the

total inorganic characteristics of a sedimentary

rock (Moore , 1949 , p . 27 ). By the reasoning

as used in lithofacies and biofacies , 11 physio­

tope11 correspond s to the designating of all

purely physiochemical elements of an environment .

Tectotope - A tectotope is a or a

of strata with characteristics

indicating accumulation in a common tectonic

environment (Sloss et . al., 1949 p . 83) . 10.

Therefore a succession of graywackes , siliceou s

, and cherts form a 0 eosynclinal tectotope ; a succession of quartzose sandstone , clay s hales ,

a nd fragmental lime stone constitute a s h elf

tectotope .

Tectofacies - A tectopacies is a g roup

of strata of different aspect from laterally

equivalent strata (see Fig . 4) . A stratigra­

phic unit may be constituted, in a given area ,

of a basin tec totope alone and thus be designated

a basin tectofacies (Sloss et . al., 1949 , p . 84 ) .

Or a unit may be composed of sixty percent e basin tectotope and forty percent shelf tectotope

and b e designated a basin-shelf tectofacles .

I I ! i ~====~~ ·-·-....!·-- ·T·-J.. SHELF ') '-...... ·- ·~ . -·-·1 '\ \-.t-----\--1 ., ·-·-·-·~. ---... r----~-1 ~----1-=~~· ---·~I .

EXAMPLE OF: TECTOFAC.IES lijTERPRETATION Figura 4 (Sloss , et . al., 1949) 11.

Magnafacies - This term refers to each major belt of deposits whic h is distinguished by similar lithologic and paleontologic

character; any one magnafacies represents a particular sedimentary environment , which p.ersisted with more or less shifting of geographic placement during a ccumulation .

An example of this is the Catskill delta of the Devonial strata, it irreg ularly trangresses time-stratigraphic planes (C aster , 1934 , p . 8 ).

Parvafacies - This is a term that refers to the portion of any i,iagnafacie s which lies between designated time planes or key beds traced across t he magnafac ies (C aster , 1934, p . 1 2 ). 12 . - EXPLANATION OF GLOSSARY

It is obvious that t here are conflict ng

definitions for the same term and conflicting

terms for the same definition . For example ,

in most cases , the berms facies and litho­

facies are synonomus . As it is connotated

by most authors however , the term lithofacies

is synnonomus with Moore ' s physiofacies . There

is not mu ch confusion with the term biofacies .

However this is probably due to the fact that

biofacies are not readily used in t he field .

Lithotope and lithofacies may be confused .

A lithotope implies those characteristics of a

sediment which reveal the environment under

which it was deposited, while a lithofacies

is the sedimentary deposit that is controlled

by and differentiated from othe r.lith ofacies

by the lithotopes . Vith these exceptions the

glossary is fairly well defined. 13.

OR IGINAL INTERPRETATIONS

To solve any problem there is one main prerequisite; and that is to know what you desire for an end product . Each author uses the facies terminology in such a manner as to accomplish the structure or special interpretation of h i s area. Thus the facies terms , which must remain flexible , are given strict definitions by these authors . An example of a special interpretation is given by Sloss , Krumbein , & Dapples . They have as their final objective a paleogeographic approach. py this they attempt to reconstruct the ancient source areas and depositional environments and distribution of the past geographic patterns (Sloss , et. al., 1949, p85 ). Caster ha s applieg t h e use of magnafacies and parvafac ies to better understand the stratigraphic relationships of the a rea in which he was working. The disagreement to usage of Caster ' s terminology is that i t confronts us 14.

with special words and concepts (King , 1949 ,

P • 165) , and that it is difficult to recognize

in the field (Moore , 1949 , p . 30) . Also

Caster ' s terms hold only if the facies planes

are not parallel to the planes of contemporanity.

If this occurs the magnafacies and parvafacies

would be synnonomus; and they would both

become time-rock units .

Facies is very important and fills a

need for a differentiated unit . It must ,

to fill the need completely, be a flexible

measure . The concept of facies implies the

difference of one sedimentary body to the

surrounding . A sedimentary facies,

would then occupy a space , a volume of existance

of any shape or size , whose boundries are

measured only by a difference of some aspect .

When facies is mentioned alone it signifies

only that there is a volume in the sediments

that is different from the surrounding sediments .

It should be properly prefixed as : geosynclinal

facies, which would imply that the boundaries of

the sediments are marked off only by the e 15.

differences of those sediments that are characteristic of a geosyncline ; it may be used as a facies , which would imply that the facies is a volume in the sediments whose boundaries are marked only by the termination of the limestone . It might well b e mentioned as a word of caution that a bit of confusion may arise if, for instance , the limestone facies in the vicinity of the area under discussion were small and scattered. Actually it should not be , and in this case the author should make it clear that this is the nature of the facies . It would be wise to compose the entire prefix of "facies" to include a geographic location and another term which designates the difference of the facies that is to be used as the marker of its boundaries in the sediments . In the above definition a more complete meaning would be to designate it the Threadgill limestone facies , which would place the limestone facies in the vicinity of threadgill . It would be just as legal to use the Threadgill Eospirifer facies , which would 16. •

imply that the boundaries that are to be marked

off only by the relative termination of the

presence of Eospirifer.

Lithofacies , biofacies , and tectofacies ,

although they do not loose their significance,

become somewhat abated in written usage . A

lithofacies implies that the boundaries

surrounding the differentiated volume is indicated

by a change in rock type . With biofacies the

difference is biologic , and with tectofacies

the difference is indicated by a change in

tectonism. Though somewhat removed from the

actual literature these terms may be used in the

following manner . When speaking, for example ,

of the Fountain arkose , which is a formation as

well as being able to be designated by facies

terms, one asks, "what s its lithofacies?"

The answer would be the Fountain arkose facies .

When asked of its tectofacies the answer would

be the Fountain zeugogeosyncline facies . Howe v er

when an author is writing an article he will not

have to designate which of these types he is

referring to because by the prefix it will be - obvious . 17 .

Caster ' s magrtafacies and parvafacies, although in limited cases , are useful tools ·of the facies concept . As mentioned before this concept would not be valicl in those cases where the facies planes are parallel to the planes of contemporaneity, as in t h e "pancake" bedding of the ~illiston Basin . It is however , valuable in those locations of a trangressing or regressing se~. This concept proved its value when it helped Caster to solve the nature of the Devonian strata in Pennsylvania. I believe t Qat the magnafacies concept is extremely more an asset than the parvafacies concept.. The parvafacies are difficult for anyone but an experienced paleontologist to decifer. There ~re those who claim that these are difficult to recognize in the field . I do not believe that Dr. Caster meant that they were easily seen . If they can be illustrated, even in a crude form, they would be valuable in giving up the secrets of areas similar to the Devonian of Pennsylvania . Another objection to Caster ' s terminology was that it was a new concept (King , 1949 , p . 165) . This is very poor and

·' 18.

very short-sighted reasoning . I wonder if Dr . King would, by the same reasoning, have objected to Hutton's uniformitarianism had he been present at the time. I believe that magnafacies and parvafacies should be used, and that by their mention should connotate

~ trangressing or regressing environment of deposition. I have given my personal conclusions, and I sincerely believe that they are the answer to the enigma of facies terminology. Facies is a flexible term that is used for all sizes , shapes , and types of sediments . This is not a far fetched idea in . For example the Alcova limestone member , which is only two feet thick, overlies the Red Peak member which is seven hundred feet thick. Therefore by the writer ' s definitions it would be proper to speak of the Jurassic facies which would be those volume of sediments that are differentiated from the surrounding sediments by the fact that they are of a different age . 19.

Or it would be proper to speak of the Chicago biohermal facies , .which would imply, that volume of sediments , in the location of Chicago, whose boundaries are selected by the contact of the bioherm with other sediments·. This system of terminology is adapted to fit any of the multitude of differentiated sediments that can be designated in no other manner , and , I believe, with this system, would fill a necessary void in the terminology of sediments . 20.

BIBLI03-R.l\.PHY

C'lster, Kenneth E., 11 The Strati,:ra9hy and of North1,restern Pennsylv"tni1., 11 Bu letin of .American Paleontolo:ists, Vol. 21 , No . 71.,. June 9 , 1934, :p • 8 - 180.

:0"_:-i::,les, E. C., Krum ein, i. C., Sloss, L.L., 11 ':!:ectonic Control of Li tholo,..,.ic Association, 11 A.A. P.~. Bull. 32 ,-"p rt 2, np. 1924 - 947.

3-riffiths, John 1'1., "Or..,l Presentation, 11 e imentarv F cies n Geolo~ic Histor , G. S.A. Memoir 39, 1949, PPP . 140- 141.

Hesse, R., r\llee, 1,r.c., an Schn dt, K.P., 11 .:cologic"'~l Ani mel Geoe;r phy, 11 N. Y., N. Y., 1937, 597n.

K1.y , Marshall, 11 An::>lYsis of Str2ti:ra9hy, 11 MPG, Vol. 31, ~p. 162 - 178.

Kin;:, Philli_ B., 11 0ral Presentation, 11 Se ime"J.tri.r1r F cies in Geolo(.f'ic Histor, G.S.A . liemoir 39 , 1949, DD. 165-171.

Krumbien, William , 11 Li thofacies i_aps and Re,.,.ional 3edimentar1 -Sty,q, t i:rq,nhic Ar1alysis, 11 A. . P. G. Bull. 32, Part~' October, 1~48, ~:p. -9-9- --1923.

Lowm'l1, S. W., 11 0r9.l Presen... '1tion, 11 Sedimentar·r Facies in Geoloe·ic History, G. S.A. Memoir 39, 1949, P.• 125 - 130. McKee, Edwin, D. , 11 Facies Ch ne;es in the Colorado Pla.te'lu, 11 Q.~.A,. I emoir 39 ,· 3e imentary Facies in Geolo,,.i nistorv, June, 1949, pD . 35 - 54.

Moore, Raymond C. , 11 .:.,tr<> ti:::.r1._ hi cal Paleontology, 11 g.~.~- Bul. 59, P..,rt _, ~9. 301 - 326 , 1948.

11 Moore, Raymond C., :r-ceani 0 1r· of Facies," Q.J.~. Memoir 39, J ne, 1949, _p. 2 - 33. 21 .

Muller, 3ie"'1on W., "Sedimentary F"tcie "1Yld Geolof"ic Structures L~ the Basin and R~n__::e Provinces," ::_.::_.I:!. I.emoir 39, J ne, 1949, :pp. 49 - 54.

1 S::)ie :er, "'"'dmund, "Sedi:ne:1t ry F 0 .cies and Associated DiastroDhism ir the U')Der Cri=>taceo, s of Co·..,tr-i '3..Yld .c..a tern Utah, 11 G.,2.~. ::emoir 39, JuYie, 1949, :?:P• 55 - P.l. "toclrd'lle, Pa.r; s 'R., 11 Lo ver I,fississi. pia.n Rocks of t'1e -.;,8st - Ce ntr-:tl Interior, 11 G.S .• Sueciel P '.)er :Ko. 22, Dece,..nber 20, 1939.

11 V'lnH01 ten, Fran1 lin B. , 11 Oral Pre sent 1. tio11, er" ir.!e:nt-:i.r1r Faci8s i11 GPolo-·ic Hi tor,r, G.q.A. Lemoir 39, '149, . '?9· 152-:: 154.

Wells, J. W., "Provision:~ P"1leoec-o o:::ic'l !18.lys s of the Devonian Roc 1ts of the Columbus Re_i on Ohio, 11 Ohio Journal of Science, Vol 47, No. 3, pu. 119 - 129, 192+7.

:iooa , Por0 ce E., 11 Oral Prese~tatio'1, 11 ~ediment'lf* F1..cies in Geo10~ ic Historv, Q.~.~. r1:e .... noir 39, 19 9, le pp. 154 - 155.