25. PLANT ORGANIC MATTER IN SEDIMENTS FROM HOLE 336, DSDP LEG 38

L.J. Bogolyubova and P.P. Timofeev, Geological Institute of the Academy of Sciences, USSR

INTRODUCTION

It was not possible to use all of the available complexmethods for an exact diagnosis of the nature of all com-ponents in the organic constituents in the sediment.This was due to a very small weight of the sample com-bined with a relatively small amount of organic carbon(0.24%-0.96%). Thus, our study was at first confined toinvestigation of organic matter in bilaterally polishedsections by translucent light under parallel and crossednicols. Secondly, a luminescent-bituminologicalanalysis was used combined with paper-chromatography (Iljina, 1975). The latter methodenabled a characterization of the peculiarities of thecomposition of the bituminous part of organic matter.The bituminous part was isolated from the sedimentsthrough cold extraction.

Analytical Methods1

In preparing the chloroform extract, 1 g of groundsediment was extracted in tubes with 2.5 ml ofchloroform without heating. The concentration ofbituminous components in the samples was examinedby visual comparison to standards of bitumens in thesame solution using a luminescent lamp. The concen-tration of bituminous components was estimated inpercent per rock. The determination of bituminosity ofsediments by this method is often distorted due to thepresence of pentacyclic condensed aromatichydrocarbon-perilen (C20H12) in chloroform extracts.They cause a pronounced bright blue luminescence ofthe extract. Therefore, for an exact determination of thecomposition of organic matter of the chloroform ex-tract, the intensity of luminescence and colorcharacteristics were evaluated with a fluorescentphotometer. The character of bituminosity was de-ciphered through chromatography. Chromatographicanalyses were carried out on FN-3(DDR) paper.Chloroform "capillary extracts" were placed on paperbands. Chromatograms were obtained by means of"segregation" of "capillary extracts" by mixing withorganic solvents: H-hexane + acetone + benzol +ethanol, the ratio being 20:3:1:1. The zones obtained"at the beginning" and "at the front" according to theirluminescent characteristics made it possible to define atype of bitumen, recognize the presence of oil, as well asrecognizing aromatic and polycyclic hydrocarbons.

Along with the study of chloroform extracts, alcohol-benzol extracts obtained from sediments were exam-ined after successively being extracted by chloroform.The ratio of luminescent intensity of chloroform andalcohol-benzol extracts serves as a criteria for the deter-

1 All sample numbers referred to herein are GIN numbers,Academy of Sciences, USSR.

mination of syngenetic or epigenetic origin bituminoussubstances in a sediment (Baranov et al., 1974).

The organic carbon content was determined inparallel weight by the wet combustion method. In anumber of typical sediments, humic acids have beenisolated by the alternative treatment of a sediment in a0.1 N solution of NaOH and a 0.17V solution of HC1during heating in a boiling water bath for 2 hours. Thetotal amount of humic acids was estimated by thegravimetric method.

RESULTS

Organic Carbon Content in Various Types of SedimentsThe amount of organic carbon (Cwg) enables a judg-

ment of the organic matter content in the sediments.Examination of the sediment section shows (Table 1)that, on the average, the highest content of organic car-bon is associated with the upper portion includingPleistocene sediments and in the middle portioncharacterized by middle Eocene sediments. The organiccarbon content in Pleistocene sediments (Samples 1003-1033) is not constant, ranging from 0.19% to 1.15%.The variations are due to peculiarities in the lithologyof the deposits. The sediments consist of interbeds oftuffaceous clayey silts and clays with sandy silts. Thelatter may have been deposited by ice-rafting ofterrigenous material. In some samples (1014, 1018,1021), the higher carbon content is related to thepresence of clay pebbles in sediment interbeds con-taining considerable amounts of brown detritus. Thedetritus has been brought in together with terrigenousmaterial of the source area. Sediments of the middlepart of the section (Samples 1035-1085) (late-middleEocene) contain much less organic carbon. In somesamples (1049, 1054, 1064) organic carbon was absent;in others it varied within 0.23%-0.41%, often decreasingto 0.11%. An increase in the organic carbon content(Table 1) is generally related to sediments containing aconsiderable admixture of coarser material (Samples1069, 1070). The least amount (or absence) is found inthin bedded sediments enriched with siliceous tests(Samples 1035, 1037, 1040, 1042) or vitroclastic tuffs(Sample 1054). The organic carbon content in middleEocene sediments (Samples 1089-1107) is generally con-stant, ranging from 0.58% to 0.88% sometimes in-creasing to 1.26% (Sample 1104). The sediments consistof zeolititized clays interbedded with layers enrichedwith sand and gravel-sized grains of weathered basaltsand acid effusives. On the whole, the organic carboncontent in sediments from the hole is relatively small.

Petrographic Composition of Plant Organic MatterThin section studies of the organic matter in the

sediments from the hole enabled recognition of the

815

L. J. BOGOLYNBOVA, P. D. TIMOFEEV

TABLE 1Amount of Organic Carbon (Corg) and Characteristics of Plant Organic Matter

Age

PLANT ORGANIC MATTER IN SEDIMENTS, HOLE 336

to xylain or xylovitrain, i.e., to the components fromthe gelinite-telinitic group (Internationales Lexicon fürKohlenpetrologie, System GIN, Academy of Science ofthe USSR, Paris, 1963; Timofeev, Yablokov, et al.,1962; Timofeev, Bogolyubova, 1965).

The coarse and fine detritus, as well as tissueremains, is brown. Its separate inclusions are structure-less, but have outlines and are attributed to vitrain. Thesmall size of the inclusions indicates they belong to thegroup of gelinite-posttelinitic components.

The gelefied homogeneous structure is structureless,brown, sometimes grayish-brown. It is a final trans-formation product of plant matter through the processof gelefication. It may originate by coagulation ofhumic acids. Based on its structural peculiarities, itbelongs to components of the gelinite-collinitic group.

Organic matter of the sapropelic series was not foundas form elements under microscope, i.e., preservedalgae. It appears to be present as a collomorf form, andis absorbed by a clayey constituent of a sediment form-ing organo-mineral complexes. If it is not masked by ahumic matter, it causes the sediments to have a dirtyyellowish tint.

The above petrographic components of the organicmatter of sediments from the hole are quantitativelybut unevenly distributed throughout the section. Mid-dle Eocene sediments generally consisting of silty clays(Samples 1089-1107) are greatly enriched with all threepetrographic groups of components of the humic series.All groups are characterized by a relatively higheramount of structureless gelefied matter that is ab-sorbed by clay material of a sediment and is a part ofthe complex of ferrum hydroxides. A higher number oftissue fragments were observed in the form of xylainand xylovitrain. They are often pyritized. A rather largeamount of brown detritus of different sizes was dis-persed in the sediment. Peculiar "microaggregates,"generally of an oval shape, of varying sizes, and with ahigher content of ferrous hydroxides were occasionallyobserved. They are separated by fissures from the restof the sediment. The distribution of tissue fragmentsand detritus is without orientation. Some areas of dis-colored clay matter were observed, as are found inhydromorphous soils. Relative enrichment of thesesediments with gelefied plant material corresponds to ahigher carbon content in this part of the section, as wellas an outflow of humic substances (Tables 1, 2).Sediments of the upper part of the section of Pleisto-cene age (Samples 1003-1033), as well as those of themiddle Eocene, are characterized by a higher content ofhumic series components. Small tissue fragments arealso frequently observed, as well as coarse and finedetritus. This detritus often is associated with claypebbles. However, gelefied structureless matter is near-ly absent.

Sediments from the middle part of the section(Samples 1035-1089) (late-middle Eocene andOligocene) are characterized by a very small amount ofhumic components. Tissue fragments in the form ofxylain and xylovitran are sporadic, being found mainlyat the base of this part of the section (Samples 1085,1070, 1058). Detritus is present in very small amounts,and its content gradually decreases upwards to singleinclusions, where clay sediments are strongly enriched

with siliceous tests (Samples 1042, 1040, 1037, 1035). Inthis part of the section, the pollen of superior plants isobserved, with sporadic resinous grains also beingfound.

Luminescent-bituminological and ChromotographicStudy

Figure 1 presents a comparison of luminescentcharacteristics of chloroform and alcohol-benzol ex-tracts of the sediments from Hole 366. Coloredcharacteristics of luminescence are plotted on the X-axis Ic/Io (Table 2), and intensity of luminescencemeasured with the help of a fluorescent photometerthrough a blue light filter are plotted on the Y-axis. Thearrangement of points of the graph corresponding tochloroform extracts enables a subdivision of thesamples into four groups. The first group includesSamples 1049, 1054, 1058, 1059, 1064, 1069, 1081, and1101. They are characterized by a weak bituminosity ofthe chloroform extract (Ic

00

00 TABLE 2Characteristics of the Organic Matter, Hole 33

Depth(m)

3.82

5.53

11.32

14.62

36.73

41.05

45.86

47.38

53.10

69.42

115.20

226.20

228.77

235.66

240.48

243.38

Sample(Interval in cm)

336-1-3, 80-82

336-14, 100-102

336-22, 80-82

336-2-4, 110-102

336-5-1,120-123

336-5-4, 103-105

336-6-1,84-86

336-6-2, 85-88

336-6-6, 58-60

336-8-4, 90-92

336-114,68-70

336-21-2, 75-77

336-21-1,75-77

336-22-1,64-66

336-22-5,96-96

336-22-6, 86-88

SamplefromGIN

Acad.Sci.

USSR

1002

1003

1006

1007

1011

1014

1017

1017b

1021

1025

1033

1048b

1049

1054

1058

1059

org

(% forT\r tr

UTyWeight)

Not

determined0.24

0.19

0.85

0.91

0.96

0.32

Notdetermined

1.15

0.23

0.26

Absent

Absent

Absent

0.36

Not

determined

Lithology

Unsorted sandy siltwith clay cementAs above

Silty clay with an ad-mixture of sandymaterial

Clayey silt, with asandy admixtureSilty clay, with sandand pebblesSandy, clayey silt

Tuffaceous silt, withsiliceous testsAs above

Silty clay, with sand

Tuffaceous clayey silt

Silty clay with siliceoustestsPelitomorphic clay withquartz grains andzeolite

Pelitomorphic clay withbasalt fragments andquartz grainsVitroclastic tuff,zeolitized

Homogeneous tuff

As above

MicroscopicCharacteristics of

Plant OrganicMatter

No plant remains

As above

As above

Brown detritus

As above

Brown detritus, claypebbles enriched withdetritusBrown detritus

As above

Clay pebbles enrichedwith detritusNo plant remains

No plant remains

Brown detritus

No plant remains

As above

Sporadic brown detritusand fragments ofgelefied tissuesAs above

Bituminosityfor Rock

Chloroform alExtracta

0.0012

0.04

0.005

0.02

0.04

0.08

0.005

0.08

0.04

0.005

0.005

0.0012

0.0003

0.0003

0.0006

0.0003

Luminescent Characteristicof Extracts

ChloroformalExtract

I blc

0.83

3.6

0.67

2.7

6.6

9.6

1.95

6.2

4.5

1.95

1.0

1.0

244.81

246.31

256.31

267.11

272.61

331.21

369.22

435.88

440.24

440.86

442.40

336-23-1, 109-111

336-23-2, 79-81

336-24-2, 79-81

336-25-3, 109-111

336-25-6, 109-111

336-30-1, 120-122

336-32-1, 120-122

336-36-1,136-138

336-36-3, 52-53

336-36-4, 122-124

336-36-5, 34-36

1060

1061

1064

1069

1070

1081

1089

1101

1103

1104

1105

Notdetermined

2.71?

Absent

0.41

0.41

0.39

0.58

0.59

0.85

1.26

0.88

As above

Clay with silt

Clay with grains ofquartz and extrusives

Clay, silty, stronglyarenaceousAs above

Silty clay with frag-ments of weatheredbasaltsClay saturated withzeolites

Zeolitized tuff

Silty, zeolizited clay

As above

As above

Brown detritus

Brown detritus andtissue fragmentsBrown detritus

As above

Brown detritus andsporadic fragments ofgelefied tissuesBrown detritus

Brown detritus,gelefied structurelessmatterSporadic brown detritus

Brown detritus, smallfragments of gelefiedtissues, gelefiedstructureless matter

0.0006

0.0012

0.0003

0.0003

0.0006

0.0003

0.0006

0.0003

0.0012

0.006

0.006

0.98

0.83

L. J. BOGOLYNBOVA, P. D. TIMOFEEV

17-

16-

15-

14-

13-

12-

11-

10-

^ . 9-

Q -O

7-

6-

5~

4-

3-

2-

1-

\\

\\\\

o2.8 \

1I

o9

/

07 o4 /

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O27O1.15/010.18 /O O26 3.14.16 /

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12.15^3.14.15.16 j f . T T , '20O2lλ 20*22.24 ) l i α

II I

I l al i bl i el i d

IcIo

• 7.

^ 1

- Alcohol-benzol extract- Chloroformal extract (hardly soluble)- Very weak bituminosity of the chloroformal extract- Weak bituminosity= Strong bituminosity and pirelen- Weak bituminosity of the chloroformal extract,

but a high color ratio- Intensity of blue luminescence of the chloroformal extract- Intensity of blue luminescence of the alcohol-benzol extract- Color characteristic

« • " " • i i j

• 6 \\

\\

\

\

•5 I• 8 'He

/

/

•2 //

•4 /

10^/

Ib ^ ^ I I d

V ^ 2 3 26 j /1 2 3 4 5 6 7 8 9

J/c

Figure 1. Luminescent characteristics of chloroformal and alcohol-benzol extracts of sediments, Hole 336.

10

i.e., Ic chloroform < Ic alcohol-benzol. In this relation,the points on the graph (Figure 1) characterizingbituminosity of alcohol-benzol extracts are located inthe left side of the area relative to the points ofchloroform extracts. This indicates a syngeneticcharacter for the bituminous components of thesediments from Hole 336. For an epigenetic characterof bituminous components, the Ic chloroform would begreater than the Ic alcohol-benzol.

In all samples (Table 2) the data of luminescent-chromatographic characteristics of chloroform extractsdo not show the zones representative of components ofthe oil type, i.e., there are no indications of the pres-ence of oil.

CONCLUSIONS

1. The distribution of organic carbon in sediments ofthe hole is variable. Roughly, a higher amount is foundin Pleistocene sediments (the upper part of the hole)and in middle Eocene sediments (the lower part of thehole).

2. A higher Corg content is observed in sedimentswith a larger grain size (related to ice-rafting ofterrigenous material [Pleistocene]), and in claysediments of the middle Eocene which indicate a closerlocation of the source of supply. A lower C

PLANT ORGANIC MATTER IN SEDIMENTS, HOLE 336

clays in sediments of the lower part of the section (mid-dle Eocene) indicate their more or less autochthonousorigin. Conversely their allochthonous character maynot be related to a distant transfer of plant material.

6. The brown color of the humic matter componentsand its solving in mononormal alkali point to a lowrank of the organic matter corresponding to the limitsof brown coal.

7. Components of an oil series have not beenrecognized during the investigation of the chloroformextract by means of paper chromatography.

REFERENCESBaranov, T.E., Belikova, A.G., and Sheinerman, N.A., 1974.

Diagnosis of syngenetic and epigenetic bituminous sub-

stances through luminescent bituminology methods:Trudy Vnigri,v. 355, p.

Iljina, A.A., 1975. Characteristics of the composition ofbituminous components of the organic matter of recentsediments based on data of the luminescent-spectralanalysis. In Transformation of organic matter in recentand fossil sediments and the main generation stages of freehydrocarbons: Trudy VNIGNI, v. 175, p. 134-142.

Timofeev, P.P., Yablokov, V.S., and Bogolyubova, L.I.,1962. Die Entstehung und die genetische Klassifikationvon Humuskohlen in den Hauptbecken der USSR:Brennstoff-Chemie, no. 4, Bd. 43, p. 97-105.

Timofeev, P.P., Bogolyubova, L.I., 1965. Genesis of humiccoals and specific features of their distribution in differenttectonic types of coal measures in the USSR. In Geologyof coal measures and stratigraphy of the carboniferous inthe USSR: Moscow (Nauka), p. 21-45.

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