-
99GEODIVERSITAS • 2002 • 24 (1) © Publications Scientifiques du
Muséum national d’Histoire naturelle, Paris.
www.mnhn.fr/publication/
Silurian and Devonian strata on the SevernayaZemlya and Sedov
archipelagos (Russia)
Peep MÄNNIKInstitute of Geology, Tallinn Technical
University,
Estonia Ave 7, 10143 Tallinn (Estonia) [email protected]
Vladimir V. MENNERInstitute of Geology and Exploitation of
Combustible Fuels (IGIRGI),
Fersman Str. 50, 117312 Moscow (Russia) [email protected]
[email protected]
Rostislav G. MATUKHINSiberian Research Institute of Geology,
Geophysics and Mineral Resources (SNIIGiMS),Krasnyj Ave 67,
630104 Novosibirsk (Russia)
[email protected]
Visvaldis KURŠSInstitute of Geology, University of Latvia,
Raina Ave 19, LV-1050 Rīga (Latvia) [email protected]
Männik P., Menner V. V., Matukhin R. G. & Kuršs V. 2002. —
Silurian and Devonian strataon the Severnaya Zemlya and Sedov
archipelagos (Russia). Geodiversitas 24 (1) : 99-122.
ABSTRACT Silurian and Devonian strata are widely distributed on
the islands of theSevernaya Zemlya and Sedov archipelagos. The
Silurian is represented byfossiliferous shallow-water carbonates
underlain by variegated sandstonesand siltstones of Ordovician age.
The Devonian consists mainly of variousred sandstones, siltstones
and argillites, with carbonates only in some inter-vals. The best
sections available for study are located in the river valleys,
andin the cliffs along the coastline of islands. Type sections of
most of the strati-graphical units identified are located on the
Matusevich River, OctoberRevolution Island. As the Quaternary cover
is poorly developed onSevernaya Zemlya, the Palaeozoic strata can
be easily traced also outside thesections.
KEY WORDSSilurian,
Devonian, Sedov Archipelago,
Severnaya Zemlya Archipelago, Russia,
lithostratigraphy, biostratigraphy.
406
-
INTRODUCTION
The Severnaya Zemlya and Sedov archipelagoslie north of the
Tajmyr Peninsula, between theKara and Laptev seas. The Severnaya
ZemlyaArchipelago, with a total area of about 37 000km2, consists
of four large islands (OctoberRevolution, Bol’shevik, Komsomolets
andPioneer) and up to 70 smaller ones. Six islands– Srednij,
Golomyannyj, Domashnij, Figurnyj,Vostochnyj and Samojlovich – form
the SedovArchipelago. About half of the SevernayaZemlya
Archipelago’s territory is covered bycontinental glaciers (Fig. 1).
Due to a very poorvegetation, the rocks are well exposed.Numerous
continuous sections of highly fossil-iferous Lower and Middle
Palaeozoic strata putthe archipelagos among the key areas for
geo-logical studies in the Circum-Arctic region. Thebeginning in
1996 of the IGCP Project 406(Circum-Arctic Lower and Middle
PalaeozoicVertebrate Palaeontology and Biostratigraphy)reactivated
the studies connected withSevernaya Zemlya. The aim of the present
paper is to give a generalidea about the sections, lithologies and
stratigra-phy of the Silurian and Devonian strata onSevernaya
Zemlya.
Männik P. et al.
100 GEODIVERSITAS • 2002 • 24 (1)
PREVIOUS STUDIES
The Severnaya Zemlya Archipelago was discov-ered in 1913. The
first evidence of the existenceof Palaeozoic strata on the
Severnaya Zemlya,but also in the Sedov Archipelago, came
fromcollections made by G. A. Ushakov and N. N.Urvantsev during the
expedition in 1930-1932.In samples from Severnaya Zemlya, B.
B.Chernyshev identified Silurian tabulates, similarto those known
from Tajmyr and NovayaZemlya. In 1948-1954, a group of
geologistsfrom the Scientific Research Institute ofGeology of
Arctic (NIIGA, St.-Petersburg), ledby B. Kh. Egiazarov, studied the
archipelagosand compiled a geological map on a scale of1:1 000 000.
A rich collection of fossils was stud-ied by A. P. Bystrov, Z. G.
Balashov, V. A.Vostokova, R. S. Eltysheva, M. S. Zhizhina,B. N.
Nalivkin, O. I. Nikiforova, V. N.Ryabinin, Ya. D. Zekkel’ and S. V.
Cherkesova.The general stratigraphy of the Palaeozoic stratawas
published in a number of papers and mono-graphs (Egiazarov 1957,
1959, 1970, 1973).Modern understanding of the Lower andMiddle
Palaeozoic strata on Severnaya Zemlyais based mainly on the data of
detailed geologi-cal mapping by V. A. Markovskij, A. A.
RÉSUMÉLes niveaux stratigraphiques silurien et dévonien des
archipels de SevernayaZemlya et de Sedov (Russie).Sur les îles de
Severnaya Zemlya et de Sedov, les niveaux du Silurien et duDévonien
sont bien représentés. Le Silurien est représenté par des
carbonatesfossilifères de dépôts peu profonds, recouverts par des
grès et des silts d’âgeordivicien. Les niveaux dévoniens sont
représentés par des grès rouges, dessilts et des argilites, qui
alternent parfois avec des niveaux carbonatés.Comme souvent, les
meilleures coupes sont localisées dans les vallées et surles
falaises le long des côtes. Les coupes-types des unités
stratigraphiquessont principalement localisées dans la vallée de la
rivière Matusevich sur l’îlede la Révolution d’Octobre. Sur
l’archipel de Severnaya Zemlya, la couver-ture quaternaire est si
réduite que les niveaux paléozoiques peuvent être faci-lement
retrouvés en dehors des coupes-types.
MOTS CLÉSSilurien,
Dévonien, archipel de Sedov,
archipel de Severnaya Zemlya, Russie,
lithostratigraphie, biostratigraphie.
-
Silurian and Devonian strata on Severnaya Zemlya
101GEODIVERSITAS • 2002 • 24 (1)
SchmidtIsland
Glacier ofAcademy of Sciences Komsomolets
Island
OctoberRevolution
Island
RusanovGlacierPioneer
Island
Golomyannyj I.
Domashnij I.
SedovArchipelago
SrednijIsland
Figurnyj I.
Pionerka R.
VkhodnojPeninsula
Vostochnyj I.
Bedov R.
Bol'shaya R.
Pod. R.
Obryv. R.
Al'banovGlac. Krasn.Bay
C
A
BMal'yutka
Glacier
KarpinskiGlacier
VstrechnayaHill
VatutinPeninsula
Glacierof
University
VavilovGlacier
Samojlovich(Dlinnyj)Island
KARA
SEA
KARA SEA
LAPTEV SEA
10 0 10 20 30 40 km
1 2 3 4Bol'shevik
Island
102°
FIG. 1. — Distribution of Palaeozoic strata on Severnaya Zemlya,
showing location of studied sections and spot samples
(geologymodified from Egiazarov 1959). Areas A, B and C show the
location of detailed maps in Figs 2; 6; 9. Areas of Silurian
outcrops stud-ied on Pioneer Island (according to Klubov et al.
1980) are indicated as follows: I, samples 2A-4G; III, samples
4D-6A, 8G; V, sample12. Samples 7A-7B, 8D-8G, 9E, 9Zh and 10A-10B
come from areas I or II (precise location not known). Bedov. R.,
Bedovaya River;Obryv. R., Obryvistaya River; Gr. R., Gremyashchaya
River; Krasn. Bay, Krasnaya Bay; Pod. R., Pod’’emnaya River. 1,
Cambrianand older rocks; 2, Ordovocian; 3, Silurian; 4, Devonian to
Quaternary strata.
-
Makar’ev, Yu. G. Rogozov, B. N. Batuev, A. F.Khapilin and others
in 1973-1979. A properstratigraphical framework for the mapping
wasprovided by special sedimentological and bios-tratigraphical
studies. During field-work in1974, 1976, 1978 and 1979, many
sections indifferent parts of the archipelagos weredescribed in
detail and fossils collected. Yu. G.Samojlovich, D. K. Patrunov and
A. A. Egorova(St.-Petersburg, Russia), V. Karatajūtē-Talimaaand J.
Valiukevičius (Lithuania), E. Mark-Kurikand P. Männik (Estonia), V.
Kuršs (Latvia),R. G. Matukhin (Novosibirsk, Russia), V. Vl.Menner
(Moscow, Russia), and B. A. Klubovand E. I. Kachanov (Magadan,
Russia) partici-pated in the expeditions. The collections
werestudied and described by A. Abushik (ostra-codes), O.
Afanassieva (vertebrates), A. Blieck(vertebrates), S. Cherkesova
(brachiopods), D.Drygant (conodonts), I. Evdokimova (ostra-codes),
V. Karatajūtē-Talimaa (vertebrates),E. Levitski (trilobites), E.
Lukševičs (verte-brates), Z. Maximova (trilobites), E. Mark-Kurik
(vertebrates), T. Modzalevskaya(brachiopods), P. Männik
(conodonts), T. Märss(vertebrates), L. Nekhorosheva (bryozoans),H.
Nestor (stromatoporoids), M. Shurygina(rugose corals), M. Smirnova
(tabulate corals),N. Sobolev (conodonts), G. Stukalina
(crinoids),V. Sytova (rugose corals), G. Vaitiekūnienē(miospores),
and J. Valiukevičius (vertebrates).A special meeting devoted to the
stratigraphy ofSevernaya Zemlya was held in Vilnius,Lithuania, in
1980, and several papers were pub-lished later (e.g., Kurik et al.
1982; Matukhin etal. 1982; Markovskij & Smirnova 1982). Also
in1980, during a meeting in Novosibirsk, an offi-cial stratigraphic
scheme of the Silurian andDevonian systems of Severnaya Zemlya was
rat-ified (Gurari & Krasilov 1982).
GENERAL GEOLOGY AND STRATIGRAPHY
The sequence of sedimentary rocks onSevernaya Zemlya ranges from
the Upper
Proterozoic on Bol’shevik Island (Kaban’kov etal. 1982) to the
Upper Palaeozoic (small oucropsof Carboniferous and Permian rocks
onBol’shevik, October Revolution andKomsomolets islands; Dibner
1982) (Fig. 1).Large areas on northern Komsomolets Islandare
covered with Cenozoic sediments. The old-est Palaeozoic strata
(Cambrian) are exposed inthe eastern part of October Revolution
Island. The Cambrian-Devonian sediments in the mid-dle and eastern
parts of October RevolutionIsland are folded, with the Silurian
andDevonian outcrops situated on the limbs of anorth-west
south-east trending anticline. Thisstructure extends to the
southwesternmostKomsomolets Island. The core of the anticline
isformed of Ordovician rocks. On westernOctober Revolution Island
and on PioneerIsland, the Palaeozoic strata are less deformed.
SILURIANThe best Silurian sections available for study
arelocated in the river valleys, perpendicular to theoutcrop belts
in the central part of OctoberRevolution Island, and in the cliffs
along thecoastline of the Sedov Archipelago islands. Over40 years
ago, Egiazarov (1959) noted that themost complete sequence of
Ordovician, Silurianand Devonian strata is exposed on theMatusevich
River (Figs 1; 2). Later, this sectionhas been studied in detail by
many geologists,and the type sections of most of the Silurian
for-mations are located there (see below). Almostcomplete, but not
studied in detail, Siluriansequences are known from the
southwesternpart of Komsomolets Island (Fig. 1), and fromsome areas
on western and northern PioneerIsland. In general, the Silurian
strata onSevernaya Zemlya are represented by fossilifer-ous
shallow-water carbonates, underlain by var-iegated sandstones and
siltstones of Ordovicianage, and overlain by mainly red terrigenous
sed-iments of Devonian age. All Silurian formationswere erected and
described during field-work in1978 by a team (included V.
Karatajūtē-Talimaa,V. Kuršs, V. Markovskij, R. Matukhin, V.Menner,
Yu. Samojlovich and J. Valiukevičius)
Männik P. et al.
102 GEODIVERSITAS • 2002 • 24 (1)
-
led by V. Menner. The Ust’-SpokojnayaFormation was originally
described as IzluchinaFormation, and was renamed later (see
below).
Llandovery and WenlockVodopad Formation. The Vodopad Formationis
the lowermost Silurian unit on SevernayaZemlya (Fig. 3). It is
named after the waterfall(in Russian, “vodopad”) on the
MatusevichRiver, October Revolution Island, where thetype section
of the formation is located (out-crops 14 and 13a; outcrop 13, beds
87-141;Figs 2; 4; 5) (Menner et al. 1979). The lowerboundary of the
Vodopad Formation corre-sponds to the level where variegated mainly
ter-rigenous rocks of the Strojnaya Formation(Upper Ordovician) are
replaced by dark greylimestones and dolostones.The formation has
highly variable lithologies,formed in open-shelf conditions during
the first
major early Silurian transgression in theSevernaya Zemlya
region. It is dominated bygrey to dark grey fine- to coarse-grained
biode-trital and dolomitic limestones. Tabulate andrugose corals,
stromatoporoids, brachiopods,ostracodes and echinoderms are
abundant, par-ticularly in the upper part of the formation.
Thelowermost and uppermost strata are rich in pen-tamerid
brachiopods. At some levels pentameridcoquinas occur. In the lower
pentamerid inter-val, Borealis Boucot, Johnson & Rubel, 1971
hasbeen identified (T. Modzalevskaya pers.comm.). An interval of
thin-bedded argillaceouslimestones, rich in stromatolites but
almostlacking other fossils, divides the VodopadFormation into two
parts, the upper one con-taining large colonies of tabulate corals
andsiliceous nodules.On October Revolution Island the thickness
ofthe Vodopad Formation varies within 240-280 m
Silurian and Devonian strata on Severnaya Zemlya
103GEODIVERSITAS • 2002 • 24 (1)
Mal'yutkaGlacier
18
18a
17
19
7
6 5 431 212
11
1314
1013a
N
1 0 1 2 3 4 km
Mat
usev
ich
Rive
r
FIG. 2. — Localities on the Matusevich River (= A on Fig. 1).
For legend refer to Fig. 1. Numbers along river correspond to
outcrops asshown on logs in Figs 4 and 12.
-
in the Ushakov and Matusevich River sections,but reaches up to
360 m in the Krasnaya Bayregion. On the Sedov Archipelago islands,
onlythe uppermost part of the formation is exposed.The Vodopad
Formation can be recognized alsoon the southwestern Komsomolets
Island.
The assemblages of stromatoporoids (includingClathrodictyon
boreale Riabinin, 1951, C. vario-lare (Rosen, 1867), Ecclimadictyon
microvesicu-losum Riabinin, 1951; H. Nestor pers. comm.),rugose
corals (Shurygina & Sytova 1999), tabu-late corals (Markovskij
& Smirnova 1982),ostracodes (Abushik 1999, in press) and
bra-chiopods (Modzalevskaya 1999, in press) indi-cate a Llandovery
age for the VodopadFormation. The assemblages of conodonts
andcrinoids occurring in this formation allow us tocorrelate it
with the upper Rhuddanian andlower Aeronian (Männik 1997, 2002;
Stukalina1999) (Fig. 3).Golomyannyj Formation. This formation
isnamed after Golomyannyj Island in the SedovArchipelago (Menner et
al. 1979) (Fig. 1).However, the type section of the formation
islocated on the Matusevich River, OctoberRevolution Island
(outcrop 13, beds 34-86; Figs2; 5). The lower boundary of the
formation istaken just above the uppermost bed with pen-tamerid
brachiopods. Sedimentological and palaeontological data sug-gest
that the strata of the Golomyannyj Forma-tion were formed in the
conditions of a majormarine regression. The formation is built up
ofthin-bedded argillaceous limestones withinterbeds of sandstone,
stromatolitic limestone,and dolostone at some levels. Mud-cracks
arecommon in many intervals. Ostracodes, gas-
Männik P. et al.
104 GEODIVERSITAS • 2002 • 24 (1)
SERIES STAGE FORMATION
Upper
Middle
Lower
Přidoli
Ludlow
Wenlock
Llando-very
Famennian
Frasnian
Givetian
Eifelian
Emsian
Pragian
Lochkovian
Ludfordian/Gorstian
Homerian/Sheinwoodian
Telychian
Aeronian
Rhuddanian
Mal'yutka
Vavilov
Matusevich
Gremyashchaya
Vatutin
Vstrechnaya
Al'banov
Rusanov
Spokojnaya
Pod''emnaya
SevernayaZemlya
KrasnayaBukhta
Ust'-Spokojnaya
Samojlovich
Srednij
Golomyannyj
Vodopad
SIL
UR
IAN
DE
VO
NIA
NS
YS
TEM
?
FIG. 3. — The sequence of Silurian and Devonian formations
ofSevernaya Zemlya and its probable correlation with the
interna-tional subdivisions of the Silurian and Devonian
Periods.
FIG. 4. — Limestones in the lower part of the VodopadFormation.
Matusevich River, outcrops 13a and 13. Photo byP. Männik.
-
Silurian and Devonian strata on Severnaya Zemlya
105GEODIVERSITAS • 2002 • 24 (1)
Matusevich River Spokojnaya RiverKrasnaya Bay
D1D1
1 2 3 4 5 6
7 8 9 10 11 12
13 14 15 16 17 18
19 20 21 22 23 24
O3
Vod
opad
Fm
. G
olom
yann
yj F
m.
Sre
dni
j Fm
.
Sam
ojlo
vich
Fm
. U
st'-
Sp
okoj
naya
Fm
.
Ust
'-S
pok
ojna
ya F
m.
Kra
snay
a B
ukht
a Fm
.
2223
1
1
50
24
1
24
1
8
9
12
1
51
1
2122
86
1
16
27
293334
8687
122123
124
141Outcrop 14
Outc
rop
13Ou
tcro
p 13
aOu
tcro
p 12
Outc
rop
11
Outc
rop
2Ou
tcro
p 11
Outc
rop
47Ou
tcro
p 45
Outc
rop
46
FIG. 5. — Silurian section on the Matusevich River, and in the
Spokojnaya River-Krasnaya Bay region (for location of outcrops
seeFigs 1; 2; 9). To the right of the lithological log are shown
the numbers of the beds described, and the extent of the outcrops
studied.The interval above bed 24 in outcrop 45 was not logged in
detail. 1, limestone; 2, argillaceous limestone; 3, dolomitized
limestone;4, limestone with pentamerids; 5, limestone with tabulate
corals; 6, limestone with stromatoporoids; 7, limestone with
stromatolites;8, coral-stromatoporoid biostromes and bioherms; 9,
oolithic limestone; 10, oncolitic limestone; 11, carbonate
conglomerates;12, silicified limestone; 13, sandstone; 14,
conglomeratic sandstone; 15, fine cross-bedding in sandstone; 16,
coarse cross-beddingin sandstone; 17, marlstone; 18, dolomitized
marlstone; 19, siltstone; 20, argillite; 21, gypsum. Colour of rock
for Fig. 12: 22, grey;23, red; 24, variegated.
-
tropods, small brachiopods and fragments ofechinoderms are
abundant in the argillaceouslimestones, whereas rugose corals,
tabulatecorals and stromatoporoids are very rare. Thebest sections
of the Golomyannyj Formation,up to 100-120 m thick, are located on
theMatusevich and Ushakov rivers (Figs 2; 5; 6). Inthe sections of
the Sedov Archipelago the thick-ness of the formation does not
exceed 60-70 m.Poor faunas from the Golomyannyj Formation,including
among others the tabulate coralsPalaeofavosites schmidti Sokolov,
1951,Mesofavosites fleximurinus Sokolov, 1951 andFavosites
gothlandicus Lamarck, 1816, ostra-codes Hogmochilina orientalis
Abushik, 1975and Tollitia navicula Abushik in press, bra-
chiopods Dubaria tenera Nikiforova &T. Modzalevskaya, 1968
and conodontsPranognathus tenuis (Aldridge, 1972) andIcriodella
aff. inconstans Aldridge, 1972, indicatean Aeronian age (Nikiforova
& Modzalevskaya1968; Markovskij & Smirnova 1982; Johnson
etal. 1997; Männik 1997, 2002; Abushik 1999, inpress; Modzalevskaya
1999, in press) (Fig. 3).In the paper by Markovskij & Smirnova
(1982)the Vodopad and Golomyannyj formations aredealt with as the
lower and upper subformationsof the Snezhinka Formation.Srednij
Formation. The Srednij Formation isnamed after Srednij Island in
the SedovArchipelago (Menner et al. 1979) (Fig. 1). Thelower
boundary of this formation corresponds
Männik P. et al.
106 GEODIVERSITAS • 2002 • 24 (1)
N31
31a 32 46
Ushakov River
VavilovGlacier 53 52
51 50
Stro
jnaya
Rive
r
1 0 1 2 3 4 km
FIG. 6. — Localities on the Ushakov and Strojnaya rivers. For
legend refer to Fig. 1. Numbers correspond to outcrop numbers.
-
to the contact between the uppermost bed ofsandstone in the
Golomyannyj Formation andthe overlying fossiliferous limestones.
Alike tothe Vodopad Formation, the Srednij Formationalso formed
during an extensive transgression.However, the sedimentological and
palaeonto-logical data suggest that the sea was shallower,and the
environmental conditions more variablethan in early Llandovery. In
its type section onthe Matusevich River (outcrop 13, beds
1-33;outcrop 12; and beds 22-23 of outcrop 11;Figs 2; 5), the
Srednij Formation consists ofcyclic intercalations of
horizontal-bedded, some-times silicified, tabulate-stromatoporoid
lime-stones with tabulate-stromatoporoid (less withalgal)
biostromes and bioherms, and thick layersof brownish-grey
limestones containing ostra-codes, gastropods, echinoderms,
cephalopodsand rare tabulate corals. The coral-stromato-poroid
biostromes and bioherms (Fig. 7) occurmore frequently in the middle
and upper partsof the formation. Interbeds of
greenish-greythin-bedded dolomitic limestones are poor infauna,
dominated mainly by ostracodes. In theseintervals, stromatolitic
limestones and mud-crack structures may occur. The thickness of the
Srednij Formation onOctober Revolution Island varies from 290 to350
m in the sections on the Matusevich andUshakov rivers, and reaches
up to 500 m in theKrasnaya Bay region. In the latter region
thelithology of the formation changes consider-ably: its lower part
(200 m) is represented bydark grey biodetrital limestones, the
middle part(150 m) consists of intercalated grey limestonesand
black marlstones with rare fauna, and theupper part (100-150 m) is
characterized bycoral-stromatoporoid biostromes and biohermsin
biodetrital limestones. The Srednij Formation can be recognized
alsoon southwestern Komsomolets Island and,probably, on Pioneer
Island. In the SedovArchipelago its thickness evidently does
notexceed 130 m, although the rocks are very simi-lar
lithologically to those in the type locality onthe Matusevich
River. According to Yu. G.Samojlovich, on Samojlovich Island the
Srednij
Formation is about 300 m thick. Here, three dis-tinct intervals
with coral-stromatoporoidbiostromes and bioherms are recognized,
andthe upper strata of the formation are consider-ably more
argillaceous than the lower ones. Although the associations of
stromatoporoids,tabulate corals, and rugose corals allow
precisecorrelation with coeval strata in Siberia, in theTiman-Urals
region, and Novaya Zemlya, cor-relation of the Srednij Formation
with the inter-national Silurian standard has for a long timebeen
unclear, because different groups of fossilshave given inconsistent
ages. The assemblages ofstromatoporoids (including Vikingia
tenuis(Nestor, 1966), Ecclimadictyon robustumNestor, 1966,
Simplexodictyon validum (Nestor,1966, etc.) and tabulate corals,
indicate aWenlock age for the Srednij Formation(Markovskij &
Smirnova 1982; H. Nestor pers.comm.). However, the ostracodes
Hogmo-chilina maackii (Schmidt, 1873), Noviportia aff.silurica
(Sarv, 1962) and some new taxa(Abushik in press), the brachiopod
Meristinanorilica (Nikiforova, 1961), and conodontsApsidognathus
sp. and some others, correlatethese strata with the Telychian
(Männik 1997,2002; Abushik 1999, in press; Modzalevskaya1999, in
press). It is this solution which is adopt-ed here (Fig.
3).Samojlovich Formation. The SamojlovichFormation (with its type
section on the
Silurian and Devonian strata on Severnaya Zemlya
107GEODIVERSITAS • 2002 • 24 (1)
FIG. 7. — Reef in the upper part of the Srednij Formation.
SrednijIsland, outcrop 1(79). Photo by P. Männik.
-
Matusevich River: outcrop 11, beds 1-21, andoutcrop 2, beds
51-86; Figs 2; 5) is named afterSamojlovich (Dlinnyj) Island in the
SedovArchipelago (Menner et al. 1979) (Fig. 1). Theboundary with
the underlying SrednijFormation is placed at the top of the
uppermost,2-3 m thick bed of limestone with
abundantstromatoporoids. The Samojlovich Formationshows rhythmic
intercalation of highly variablelimestones (grey stromatolitic,
oolitic andoncolitic limestones; greenish-grey
thin-beddedargillaceous limestones with numerous gas-tropods,
brachiopods, ostracodes and trilobites),with almost unfossiliferous
dolomitic lime-stones and argillaceous dolostones. In thedolomitic
rocks mud-cracks are quite common.Characteristically, the
Samojlovich Formationalmost totally lacks beds with tabulates
andstromatoporoids, but contains abundant stro-matolitic structures
(including stromatolitic bio-stromes; Fig. 8). With the
stromatolitic strata areconnected numerous lens-like interbeds of
car-bonate conglomerates. In most of theseinterbeds the pebbles are
inclined. Tabulate, andalso rugose corals, have only been
recordedfrom some beds in the upper SamojlovichFormation. In the
uppermost strata of the for-mation the number and taxonomic
variation offossils decrease rapidly, and the content ofsandy
material increases. Sedimentological fea-
tures in the Samojlovich Formation indicate thatthese strata
were formed in shallow-waterrimmed-shelf environments, under
conditionsof continuous shallowing of the basin.In the sections on
the Ushakov and Matusevichrivers the formation thickness is 240-280
m,increasing to 400 m in the Krasnaya Bay region,as does also the
content of clay in the rocks. Theformation has been recorded also
on southwest-ern Komsomolets Island (150-180 m thick), inseveral
regions on Pioneer Island, and in theSedov Archipelago (Srednij and
Samojlovichislands; Fig. 1).The age of the Samojlovich Formation is
stillunder discussion. Traditionally, based on theassemblages of
stromatoporoids, tabulate corals,ostracodes and brachiopods, the
lowerSamojlovich Formation has been considered oflate Wenlock age,
and the upper part of Ludlowage (Abushik 1982; Smirnova 1982;
Markovskij& Smirnova 1982; Matukhin et al. 1982; Kuriket al.
1982). However, the occurrence of anApsidognathus-fauna in the
lower SamojlovichFormation suggests a Telychian age for
thesestrata, whereas the conodonts Ozarkodinaconfluens bucerus
(Viira, 1983) and Kockelellacf. ortus (Walliser, 1964), and the
vertebrateLoganellia grossi Fredholm, 1990 indicate mid-dle to late
Wenlock age for the upper part of theformation (Männik 1997, 2002;
Märss &Karatajūtē-Talimaa in press) (Fig. 3).Ust’-Spokojnaya
Formation. This stratigraphicunit was originally described as the
IzluchinaFormation (Menner et al. 1979), but was laterrenamed the
Ust’-Spokojnaya Formation(Menner et al. 1982). The new name is
derivedfrom the Spokojnaya River, as the mostcomplete sections of
this formation occur closeto the river mouth (Fig. 9). However, the
typesection of the Ust’-Spokojnaya Formation islocated on the
Matusevich River (outcrop 2,beds 1-50; Figs 2; 5). The lower
boundary ofthis formation corresponds to the base of thelowermost
distinctive sandstone bed. On theMatusevich and Ushakov rivers the
upper partof the formation has been eroded beforeDevonian
sedimentation started, and its upper
Männik P. et al.
108 GEODIVERSITAS • 2002 • 24 (1)
FIG. 8. — Stromatolites in the middle part of the
SamojlovichFormation. The length of the hammers handle is about 80
cm.Ushakov River, outcrop 32. Photo by P. Männik.
-
boundary corresponds to the erosional surfaceat the base of the
Severnaya Zemlya Formationof early Devonian age (Figs 5; 10). The
upperpart of the formation is available for study onlyin the
Krasnaya Bay region, near the mouth ofthe Spokojnaya River (section
47, beds 9-12;Figs 5; 9). Here, the upper boundary of the
Ust’-Spokojnaya Formation corresponds to the tran-sition from
variegated marlstones withostracodes to the red sandstones and
argillites ofthe overlying Krasnaya Bukhta Formation.The
Ust’-Spokojnaya Formation consists main-ly of brownish-red,
violet-grey and greenish-grey marlstones with thin lens-like
interbeds ofargillaceous limestone containing ostracodes,bivalves,
gastropods, and vertebrate remains(Fig. 11). Interbeds of grey,
greenish-grey anddark grey fine-grained and oolitic
limestonescontaining bivalves, ostracodes,
cephalopods,stromatolites and oncolites, characterize thelowermost
part of the formation. Stromatopo-roids, rugose and tabulate
corals, and echino-
derms have not been found. The lowermost partof the formation
contains interbeds of sand-stone, and thin beds of dolostone are
common.The lithology of the Ust’-Spokojnaya Formationindicates the
continuous shallowing of the sedi-mentary basin, and an increasing
input of red ter-rigeneous material from neighbouring land
areas.The thickness of the Ust’-SpokojnayaFormation is highly
variable: from 60-100 m inthe central part of October Revolution
Island(where the upper strata of the formation aremissing) to
270-340 m in the Kasnaya Bayregion. Strata on Komsomolets Island,
probablycorresponding to this formation are 180 m thick.The
Ust’-Spokojnaya Formation can be recog-nized also on Pioneer
Island, and probably alsoin the eastern part of the Sedov
Archipelago(Figurnyj and Vostochnyj islands; Fig. 1).The
Ust’-Spokojnaya Formation is of Ludlowage based on the occurrence
of the vertebratesTremataspis obruchevi Afanassieva &
Karatajūtē-Talimaa, 1998, Paralogania martinssoni (Gross,
Silurian and Devonian strata on Severnaya Zemlya
109GEODIVERSITAS • 2002 • 24 (1)
5048
49
162
163164 165
42
505
627
157158
161
51
44 506
43
512
40?509
52
? 1341 46
45
47
RusanovGlacier
KrasnayaBay
Spokojnaya River
159
160
N
1 0 1 2 3 4 km
FIG. 9. — Localities in the Spokojnaya River region. For legend
refer to Fig. 1. Numbers correspond to outcrops.
-
1967), Phlebolepis elegans Pander, 1856, andAndreolepis sp., and
also on the ostracodesEukloedenella posterioalta Abushik,
1980,Herrmannina nana Abushik, 1960, H. hebesAbushik, 1980,
Tollitina minuta (Abushik,
1980) (Märss et al. 1995; Abushik & Evdo-kimova 1999;
Abushik 1999, in press; Karatajūtē-Talimaa & Märss in press)
(Fig. 3).Krasnaya Bukhta Formation. The KrasnayaBukhta Formation is
named after Krasnaya Bay(in Russian “bukhta”), October
RevolutionIsland (Menner et al. 1982) (Fig. 1). Its typesection
lies close to the northern coast of thisbay, about 0.5 km east from
the mouth of theSpokojnaya River (outcrop 47, beds 1-8; out-crop
45; and beds 1-24 of outcrop 46; Figs 5; 9). The Krasnaya Bukhta
Formation represents theyoungest part of the Silurian sequence
onSevernaya Zemlya. It contains brownish-redsiltstones, argillites,
marlstones and sandstoneswith rare interbeds of greenish-grey
marlstonesand argillaceous limestones. In the carbonateinterbeds
ostracodes, bivalves, vertebrates andcharophytes (algae) have been
found. At thelower boundary of the Krasnaya BukhtaFormation
variegated marlstones, characteristicof the underlying
Ust’-Spokojnaya Formation,are replaced by red sandstones (Fig. 5).
The sed-iments of the Krasnaya Bukhta Formation wereevidently
deposited in shallow-water restrictedmarine environments during a
continuingregression of sea. Most common in the poorfauna of this
formation are micro- and macro-remains of vertebrates, but some
beds also con-tain ostracodes and charophytes occur.The total
thickness of the Krasnaya BukhtaFormation in the region just north
fromKrasnaya Bay is about 350-400 m. To the westthe thickness of
the formation decreases rapidlydue to the pre-Devonian denudation
of upperSilurian strata. It does not exceed 100-150 m inthe
outcrops to the west of the SpokojnayaRiver. Further to the north
from Krasnaya Bay,in the Bedovaya River region, the thickness ofthe
formation increases to 600-700 m. Beside thenortheastern part of
October Revolution Island,the Krasnaya Bukhta Formation can
probablybe recognized only on southwestern Komso-molets Island, and
on Pioneer Island.Thelodonts Paralogania cf. borealis
(Karatajūtē-Talimaa, 1978), Loganellia cuneata (Gross,1947),
Gonioporus alatus (Gross, 1947) and the
Männik P. et al.
110 GEODIVERSITAS • 2002 • 24 (1)
FIG. 10. — The Silurian-Devonian boundary between argilla-ceous
limestones below and conglomeratic sandstones above.The hammer lies
on the upper surface of the Silurian strata.Matusevich River,
contact between sections 2 (below) and 1(above). Photo by P.
Männik.
FIG. 11. — Dolomitic marlstones and argillaceous dolostones
ofthe Ust’-Spokojnaya Formation. Matusevich River, outcrop 2.Photo
by P. Männik.
-
osteostracan Hemicyclaspis sp. correlate theKrasnaya Bukhta
Formation with the Přidoli(Märss & Karatajūtē-Talimaa in press)
(Fig. 3).Acanthodians, represented by the Poracantho-des punctatus
Zone assemblage (Valiukevičius1999, in press), and ostracodes are
also indica-tive of a Přidoli age (Abushik & Evdokimova1999;
Abushik 1999, in press).
DEVONIANOn October Revolution Island, but particularlyon
Komsomolets and Pioneer islands, theDevonian strata are more widely
distributedthan the Silurian sediments. In the SedovArchipelago,
the Devonian is known only fromFigurnyj and Vostochnyj islands
(Fig. 1). Elevenformations, most of them recognized all overthe
archipelago, are identified in the almostcomplete Devonian sequence
on SevernayaZemlya, and all standard Devonian stages arerepresented
by deposits (Fig. 3). Most of theformations were originally defined
anddescribed in the continuous Devonian sectionon the Matusevich
River, October RevolutionIsland (Menner et al. 1979). However,
later itappeared that in several sections on Pioneer andKomsomolets
islands some intervals of theDevonian sequence are more completely
repre-sented than along the Matusevich River.
Lower DevonianSevernaya Zemlya Formation. The SevernayaZemlya
Formation was originally described in1978 (Menner et al. 1979). Its
lower boundarycorresponds to the base of coarse-grained
con-glomeratic sandstones unconformably overlyingthe rocks of the
Krasnaya Bukhta or Ust’-Spokojnaya formations (Fig. 10). The type
sec-tion of the Severnaya Zemlya Formation islocated on the
Matusevich River (outcrop 1,beds 21-28; Figs 2; 12). The Severnaya
Zemlya Formation can be subdi-vided into lower and upper parts. On
OctoberRevolution Island, in the sections on theMatusevich, Ushakov
and Spokojnaya rivers(Figs 2; 6; 9; 12), the basal strata of the
lowerSevernaya Zemlya Formation are represented
by greenish-grey coarse-grained sandstoneswhich contain numerous
lenses or interbeds ofconglomerates with pebbles of different
Silurianrocks. Higher in the sequence, these sedimentsare replaced
by variegated siltstones andargillites. The upper part of the
Severnaya ZemlyaFormation consists of dark grey slate-like
lime-stones, marlstones and argillites with numerousflat nodules
holding well-preserved (often com-plete) fish remains, eurypterids,
ostracodes andalgae (Fig. 13). The thickness of the lower partof
the formation varies between 17 and 70 m,and of the upper part
between 20 and 30 m. Thetotal thickness of the Severnaya
ZemlyaFormation on October Revolution Island is 30-100 m, and on
Komsomolets Island it is also upto 100 m thick. The formation has
also beenidentified on Pioneer Island but its thicknessthere is not
known.The association of heterostracans, representedby the genera
Anglaspis Jaekel, 1926, CorvaspisWoodward, 1934, Ctenaspis Kiaer,
1930,Lepidaspis Dineley & Loeffler, 1976, PhialaspisWills,
1935, Protopteraspis Leriche, 1924,Tesseraspis Wills, 1935 and
Unarkaspis? Elliott,1983, indicates a Lockhovian age for
theSevernaya Zemlya Formation (Karatajūtē-Talimaa & Blieck
1999) (Fig. 3). The Lockho-vian age is also evidenced by
acanthodians,represented here by the assemblage of thePoracanthodes
menneri Subzone (lower part ofthe Nostolepis minima Zone;
Valiukevičius inpress), and the ostracode Herrmannina
convexaAbushik, 1980 (Abushik & Evdokimova 1999;Evdokimova
& Abushik in press).At the end of the Silurian, sedimentation
termi-nated in several areas on Severnaya Zemlya andthe uppermost
Silurian strata were denudated.The early Lochkovian time was
characterizedby a new transgression in this region but eventhe
uppermost strata of the Severnaya ZemlyaFormation formed still in
extremely shallow-water conditions, in an environment closest
tolagoonal.Pod’’emnaya Formation. The Pod’’emnayaFormation is named
after the Pod’’emnaya
Silurian and Devonian strata on Severnaya Zemlya
111GEODIVERSITAS • 2002 • 24 (1)
-
Männik P. et al.
112 GEODIVERSITAS • 2002 • 24 (1)
Sev
erna
ya Z
emly
a Fm
.
S
Vatu
tin F
m.
Mat
usev
ich
Fm.
Vavi
lov
Fm.
Mal
'yut
ka F
m.
Gre
mya
shch
aya
Fm.
Mat
usev
ich
Fm.
Pod
''em
naya
Fm
. S
pok
ojna
ya F
m.
Rus
anov
Fm
. A
l'ban
ov F
m.
Vst
rech
naya
Fm
. 153152
8584
6 133
69
11
30
5
11
71
4645
3938
1514
110 114
1 1
2021
153152
63
1 218
3837
59
91
102
63
58
28
Outc
rop
5Ou
tcro
p 4
Outc
rop
3Ou
tcro
p 1
Outc
rop
6Ou
tcro
p 7
Outc
rop
19
Outc
rop
18a
Outc
rop
18Ou
tcro
p 17
Outc
rop
19
FIG. 12. — Devonian section on the Matusevich River (for
location of outcrops see Figs 1 and 2; for legend refer to Fig. 5).
To the rightof the lithological log are shown the rock colour, the
numbers of the beds described, and the extent of the outcrops
studied. Theinterval above bed 6 in outcrop 18a was not described
in detail. Abbreviation: S, top of Silurian strata (Ust’-Spokojnaya
Formation).
-
River (western October Revolution Island),where a section
yielding the richest assemblagesof vertebrates was described
(Menner et al.1979). The type section is located on theMatusevich
River (outcrop 1, beds 1-20; out-crops 3 and 4; outcrop 5, beds
1-14; Figs 2; 12).The lower boundary of the Pod’’emnayaFormation
corresponds to the upper surface ofthe dark grey carbonate
argillites of the under-lying Severnaya Zemlya Formation, and
itsupper boundary to the base of the variegatedsandstones of the
overlying SpokojnayaFormation.On October Revolution Island the
Pod’’emnayaFormation was differentiated into two parts.The lower
part comprises grey siltstones andquartz-feldspar sandstones with
interbeds ofargillites, and contains plant fossils and rare
ver-tebrates. The upper part consists of a rhythmicintercalation of
reddish-brown and greenish-grey sandstones, siltstones, and
argillites withinterbeds of variegated argillaceous
dolostonesyielding concretions of celestite. Flat nodules ofgypsum
are common. Ostracodes and fishremains occur in abundance in
dolostones.The lower part of the Pod’’emnaya Fomation is50-90 m
thick, and the upper part is 80-190 mthick. The total thickness of
the formation onOctober Revolution Island varies from 160
m(Pod’’emnaya River) to 280 m (SpokojnayaRiver). The Pod’’emnaya
Formation is also wellexposed on Komsomolets and Pioneer
islands.The age of the Pod’’emnaya Formation, basedon the
associations of ostracodes (Leperditia cf.marinae Abushik, 1980,
Herrmannina aff.orbiculata Abushik, 1980,
Hogmochilinaisochilinoides (Jones, 1883) and H. teres Solle,1935),
and heterostracans (identical to those inthe Severnaya Zemlya
Formation; see above), isLochkovian (Abushik & Evdokimova
1997,1999; Evdokimova & Abushik in press;Karatajūtē-Talimaa
& Blieck 1999). The acan-thodians, represented by the
Diplacanthuspoltingi Subzone (upper part of the Nostolepisminima
Zone) fauna, correlate the Pod’’emnayaFormation with the upper
Lochkovian(Valiukevičius in press) (Fig. 3).
Spokojnaya Formation. The SpokojnayaFormation is named after the
Spokojnaya River,at the middle course of which one of the
mostcomplete sections of this formation is located(Menner et al.
1979) (Fig. 14). The type sectionof this formation is located on
the MatusevichRiver (outcrop 5, beds 15-38; Figs 2; 12). Itslower
boundary corresponds to the base of var-iegated sandstones and
siltstones, and its upperboundary to the base of grey dolostones
orlimestones of the overlying Rusanov Formation.The lower part of
the Spokojnaya Formation (1-151 m thick) is represented by red and
variegat-ed quartz-feldspar sandstones, siltstones andargillites.
In some sections also intervals of var-iegated marlstones occur.
Fossils in the lower
Silurian and Devonian strata on Severnaya Zemlya
113GEODIVERSITAS • 2002 • 24 (1)
FIG. 13. — Severnaya Zemlya Formation. In the centre of the
fig-ure (cliff), argillaceous limestones and argillites of the
upper partof the formation are exposed. Spokojnaya River, outcrop
41(?).Photo by V. Menner.
FIG. 14. — Spokojnaya Formation. Spokojnaya River, outcrop43.
Photo by V. Menner.
-
Spokojnaya Formation are mainly representedby vertebrates.Higher
in the sequence, variegated terrigenoussediments are gradually
replaced by grey argilla-ceous carbonate rocks indicative of the
develop-ing Early Devonian transgression in theSevernaya Zemlya
region. The upper part of theformation (50-145 m thick) consists of
grey, andsome greenish-grey, dolomitic marlstones withinterbeds of
grey argillaceous dolostones andsiltstones. In the sections where
the formation isthicker, numerous interbeds of gypsum occur inthe
dolomitic marlstones. Fossils in the upperSpokojnaya Formation are
represented by rareostracodes, bivalves, stromatolites and
verte-brates. On October Revolution Island the thickness ofthe
formation varies widely, from 25 m on thePod’’emnaya River up to
300 m on theSpokojnaya River. In the Matusevich andUshakov rivers’
sections it is about 80-90 mthick, and on Komsomolets and Pioneer
islandsup to 100 m thick. The comparison of the vertebrate
assemblagesfrom the Spokojnaya Formation with those fromSpitsbergen
and other regions has revealed thatthis formation, most probably,
corresponds tothe boundary beds of the Lochkovian andPragian stages
(Afanassieva & Karatajūtē-
Talimaa 1999; Karatajūtē-Talimaa & Blieck 1999;Mark-Kurik
1999). However, considering theages of the underlying Pod’’emnaya
Formation(see above), and the overlying Rusanov Forma-tion (see
below), the Spokojnaya Formation iscorrelated with the Pragian
(Fig. 3). Rusanov Formation. The Rusanov Formationwas originally
described by Egiazarov (1959) onPioneer Island, in the valley of
the PionerkaRiver. The name was given in the honour ofV. A.
Rusanov, an Arctic explorer. Later, in1972-1979, during the
geological mapping ofSevernaya Zemlya and special
stratigraphicalstudies, a new type section for this formationwas
selected and described on the MatusevichRiver, about 3 km upstream
from the waterfalls(Menner et al. 1979; outcrop 5, beds 39-45;Figs
2; 12; 15). Here, the lower boundary of theRusanov Formation
corresponds to the base ofgrey limestones or dolostones containing
a richassemblage of marine invertebrates. The Rusanov Formation is
known fromOctober Revolution, Komsomolets and Pioneerislands in
Severnaya Zemlya, and from FigurnyjIsland in the Sedov Archipelago.
In all knownsequences a carbonaceous lower member and agypsum-rich
upper member are distinguished inthis formation. A rich association
of fossils inthe lower member allows detailed correlation of
Männik P. et al.
114 GEODIVERSITAS • 2002 • 24 (1)
FIG. 15. — Rusanov and Al’banov formations, and the lower-most
part of the Vstrechnaya Formation. Boundaries betweenformations are
indicated by lines. Abbreviations: D1rs, RusanovFormation; D1al,
Al’banov Formation; D2vs, VstrechnayaFormation. Matusevich River,
outcrop 5. Photo by V. Menner.
FIG. 16. — The contact between the argillites of the
VatutinFormation (D2vt) and coarse-grained sandstones of
theGremyashchij Formation (D2gr). Matusevich River, outcrop 7.Photo
by P. Männik.
-
these strata with the sequences on Tajmyr andNovaya Zemlya, but
also with the internationalDevonian standard.The lower member of
the Rusanov Formationon October Revolution Island (17-50 m thick)
isrepresented by grey dolomitized limestones(Fig. 15). In the
middle of this interval a numberof interbeds rich in
stromatoporoids, tabulateand rugose corals, brachiopods, bivalves,
ostra-codes, trilobites, echinoderms and vertebratesoccur. In some
beds stromatoporoids formsmall bioherms. Dolomitization of these
lime-stones is probably connected with a stratigraph-ical gap
between the lower and upper parts ofthe Rusanov Formation. The
upper member ofthe Rusanov Formation (20-50 m thick) consistsof
grey gypsum interbedded with dolostones. In southwestern
Komsomolets Island, and onPioneer Island, the limestones of the
lowerRusanov Formation are less dolomitized thanon October
Revolution Island. Here, an intervalrich in stromatoporoids,
tabulate and rugosecorals, brachiopods, echinoderms, trilobites
andconodonts occurs in the lower part of these stra-ta. Higher in
the sequence is an interval of lime-stones and dolostones, not
known in thesections of the Rusanov Formation on OctoberRevolution
Island. In this interval stromato-poroids and corals are missing,
but brachiopods,trilobites and vertebrates are common. Thethickness
of the lower member of the RusanovFormation in this region is
85-110 m, and theupper member is 50-135 m thick. The lower strata
of the Rusanov Formation wereformed during the maximum
transgression of theEarly Devonian in the Severnaya Zemlya
basin.This is the only interval in the Devonian se-quence on
Severnaya Zemlya containing rich andvariable invertebrate faunas.
The late Rusanovtime was characterized by a rapid regressionwhich
resulted in deposition of evaporites. According to Valiukevičius
(1999), the upperpart of the lower member of the RusanovFormation
corresponds to the lower part of his“Beds with Watsonacanthus
costatus”. Based onthe co-occurrence in these strata of
acanthodi-ans and conodonts (Pandorinellina exiqua exi-
qua (Philip, 1966), P. expansa Uyeno & Mason,1975, etc.),
the “Beds with W. costatus” correlatewith the dehiscens-inversus
conodont zones(lower-middle Emsian; Valiukevičius in press).The
Emsian age of the upper part of the lowermember is also supported
by the containedostracodes (Abushik & Evdokimova
1997;Evdokimova & Abushik in press). However, theoccurrence of
the ostracode Eomoelleritia kon-diaini Abushik, 1972 in the lower
part of thismember indicates a Pragian age. The upperPragian-Emsian
age of the Rusanov Formationis evidenced also by other marine
invertebrates(Khapilin 1982; Kurik et al. 1982; Menner et al.1982)
(Fig. 3).Al’banov Formation. The Al’banov Formationwas originally
described by Egiazarov (1959) inthe sections on the Pionerka and
Burnaya rivers,Pioneer Island. The formation was named inhonour of
V. I. Al’banov, an Arctic explorer. In1979 a new type section for
the Al’banovFormation was described on the MatusevichRiver, October
Revolution Island (Menner et al.1979; outcrop 5, beds 46-84; Figs
2; 12; 15). Thedistribution of the Al’banov Formation coin-cides
with that of the Rusanov Formation. Thelower boundary of the
Al’banov Formation ismarked by the disappearance of gypsum, whichis
characteristic of the upper member of theRusanov Formation.In the
section on the Matusevich River, twomembers (respectively 48 m and
34 m in thick-ness) were recognized in the Al’banov Forma-tion. The
basal beds of the lower Al’banovFormation consist of grey dolomitic
marlstonesand dolostones followed by an intercalation ofgrey
dolostones, limestones and greenish-greyargillaceous limestones
containing fish remains,large ostracodes, eurypterids and bivalves.
Theupper member of the Al’banov Formation isrepresented by an
intercalation of light variegat-ed siltstones, sandstones and
argillites rich inaggregates of siderite, and containing
interbedsof oolitic goethite ore and breccia. In severalsections a
big stratigraphical gap has been iden-tified between the lower and
upper members ofthe Al’banov Formation.
Silurian and Devonian strata on Severnaya Zemlya
115GEODIVERSITAS • 2002 • 24 (1)
-
In the Pod’’emnaya River region the upper car-bonate interval of
the lower part of the lowermember of the Al’banov Formation is
mostlymissing. Here the total thickness of the forma-tion is only
c. 36 m. On Komsomolets andPioneer islands the lithology of the
lower mem-ber of the Al’banov Formation is similar to thaton the
Matusevich River, and its upper part isrepresented by grey and red
argillites. These aremissing from the October Revolution
Islandsequence, either due to a stratigraphical gap orto facies
changes.The strata of the Al’banov Formation wereformed during
alternating short-term transgres-sions and regressions in a
generally shallowingbasin, which was evidently still connected
withthe marine basins in northern Europe and Siberia.Egiazarov
(1957) considered the Al’banovFormation to be of Givetian age.
However, laterpalaeontological studies have revealed a
consid-erably older age, with acanthodians characteris-tic of the
“Beds with Watsonacanthus costatus”indicating an Emsian age
(Valiukevičius 1999)(Fig. 3). The Emsian age is supported by
theoccurrence of a rich and diverse assemblage ofplacoderms,
several representatives of which(Wijdeaspis Obruchev, 1964, early
heterostiids,buchanosteids, etc.) have a global
distribution(Mark-Kurik 1991, 1998). The fauna of ostra-codes in
this formation, almost identical to thatin the upper part of the
lower member of theRusanov Formation, is also Emsian in age
(seeabove; Evdokimova & Abushik in press).
Middle DevonianThree formations – Vstrechnaya, Vatutin
andGremyashchaya – have been established in theMiddle Devonian
sequence in the central andwestern parts of the Severnaya
ZemlyaArchipelago (Fig. 3). Type sections of all theseformations
are located on the Matusevich River.Quite probably the basal strata
of the overlyingMatusevich Formation are also of MiddleDevonian age
(see below). The sediment sequence in the Vstrechnaya andVatutin
formations indicates a gradual deepen-ing of the sea in the
Severnaya Zemlya region
after an extensive regression in late Emsian (theupper Al’banov
Formation; see above). Thestrata of the upper Gremyashchaya
Formationwere deposited in conditions of a new regres-sion. On the
geological map of SevernayaZemlya, compiled by V. Markovskij, the
stratacorresponding to the Vstrechnaya, Vatutin andGremyashchaya
formations are indicated as asingle unit – the Geographers
Formation withits type section on Komsomolets Island (Gurari&
Krasilov 1982).Vstrechnaya Formation. The formation isnamed after
hill Vstrechnaya in the western partof October Revolution Island
(Fig. 1) (Menneret al. 1979). The type section of the formation
islocated on the Matusevich River (outcrop 5,beds 85-152; Figs 2;
12). The lower boundary ofthe Vstrechnaya Formation corresponds to
thebase of the coarse-grained sandstones contain-ing Middle
Devonian vertebrates. In the sectionson the Matusevich, Ushakov and
Pod’’emnayarivers, and close to the northern coast ofOctober
Revolution Island, the VstrechnayaFormation consists of
rhythmically intercalatingbrownish-red terrigenous sediments. The
basalparts of the cycles are composed of coarse-grained
cross-bedded sandstones with lenses orlens-like interbeds of
conglomerates, haematiticpebbles and bone-breccias. Higher in the
cyclesthe grain size in sandstones decreases, and theirupper parts
are represented by siltstones andargillites. Commonly, the bases of
the cyclesexhibit erosional surfaces. Ostracodes, inarticu-late
brachiopods and plant remains are found inthe siltstones and
argillites. In the western partof the Severnaya Zemlya Archipelago,
onKomsomolets and Pioneer islands, red sand-stones of the lower
Vstrechnaya Formation arereplaced by light-grey and yellowish-grey
ones.The thickness of the Vstrechnaya Formation onOctober
Revolution Island varies between 70and 160 m, except in the north,
in theObryvistaya River region, where its thicknessmay reach some
400 m.The association of Psammosteidae in theVstrechnaya Formation
is typical of the MiddleDevonian (Karatajūtē-Talimaa pers.
comm.).
Männik P. et al.
116 GEODIVERSITAS • 2002 • 24 (1)
-
The assemblages of placoderms indicate anEifelian to Givetian
age (Mark-Kurik 1998, pers.comm.). Acanthodians of the
Diplacanthussolidus Assemblage from the upper part of theformation
also indicate an Eifelian-Givetian age(Valiukevičius 1999, in
press) (Fig. 3).Vatutin Formation. This formation is namedafter the
Vatutin Peninsula on western OctoberRevolution Island, where it is
well exposed(Fig. 1) (Menner et al. 1979). The best sectionsof the
Vatutin Formation are located on theMatusevich and Pod’’emnaya
rivers, and closeto Vstrechnaya hill. The type section of the
for-mation is located on the Matusevich River (out-crop 5, bed 153;
outcrop 6, and outcrop 7, beds1-37; Figs 2; 12; 16). The lower
boundary of theVatutin Formation corresponds to the uppersurface of
the sandstones of the underlyingVstrechnaya Formation, and its
upper boundaryto the base of the basal sandstones of the overly-ing
Gremyashchaya Formation.The 100-130 m thick Vatutin Formation
con-sists mainly of rhythmically intercalating red-dish-brown
siltstones and argillites with rarethin interbeds of greenish-grey
dolomitic marl-stones. Sandstones are missing. The basal part ofthe
formation includes beds of grey argillitescontaining nodules of
gypsum, shells of LingulaBruguière, 1797, and ostracodes. Plant
remainsare also quite common.The age of the Vatutin Formation is
problemat-ic, but rare psammosteid heterostracans(Psammolepis
Agassiz, 1844, Tartuosteus?Obruchev, 1961, Psammosteus Agassiz,
1844)suggest Givetian age (Mark-Kurik pers. comm.)(Fig.
3).Gremyashchaya Formation. The Gremyash-chaya Formation is named
after the Gremyash-chaya River, a tributary of the Pod’’emnayaRiver
in the western part of October RevolutionIsland (Fig. 1) (Menner et
al. 1979). Its type sec-tion is located on the Matusevich River
(outcrop7, beds 38-58; Figs 2; 12). The GremyashchayaFormation
consists of yellowish and violetcoarse- to fine-grained quartz
sandstones withrare interbeds of conglomerates, red
siltstones,argillites and marlstones. Thin interbeds of
oolitic or nodular limestones occur at some lev-els. In the
coarse-grained sandstones large frag-ments of fossil plants occur,
and ostracodes andstromatolites are common in the argillites
andmarlstones. The formation is characterized byabundant and
well-preserved vertebrateremains. The lower boundary of
theGremyashchaya Formation is marked by theappearance of
coarse-grained sandstones abovethe fine-grained sediments of the
VatutinFormation (Fig. 16).The thickness of the Gremyashchaya
Formationon October Revolution Island varies from 15 mon the
Pod’’emnaya River, 70 m on theMatusevich River, to up to 150 m on
theObryvistaya River. The association of vertebrates indicates a
corre-lation of the Gremyashchaya Formation withthe middle Givetian
Abava Regional Substage inthe Baltic sequence (Mark-Kurik
1998).
Upper DevonianMatusevich, Vavilov and Mal’yutka
formationscorrespond to the Upper Devonian onSevernaya Zemlya (Fig.
3). However, it is quitepossible that the basal strata of the
MatusevichFormation are still of Middle Devonian in age(see below).
Type sections of all these forma-tions are located on the
Matusevich River. TheMatusevich and Vavilov formations have
beenrecognized on October Revolution andKomsomolets island, the
Mal’yutka Formationonly in the central part of the
OctoberRevolution Island.Lithological changes in the
MatusevichFormation reflect the cyclic development of theFrasnian
transgression, the sediments of theVavilov Formation formed in time
when the sealevel reached its highest position in lateFrasnian, and
those of the Mal’yutka Formationalready in conditions of the
Famennian regres-sion. Matusevich Formation. The formation
waserected by Egiazarov (1957) and named after theMatusevich River,
October Revolution Island.Later, the boundaries of the formation
havebeen revised (Menner et al. 1979). The type
Silurian and Devonian strata on Severnaya Zemlya
117GEODIVERSITAS • 2002 • 24 (1)
-
section of the Matusevich Formation is locatedon the Matusevich
River (outcrop 7, beds 59-102; outcrops 19, 17, and beds 1-5 of
outcrop 18;Figs 2; 12). Its lower boundary corresponds tothe base
of a very distinctive bed of coarse-grained conglomeratic
sandstones.The strata of the Matusevich Formation areexposed on
October Revolution andKomsomolets islands. The formation shows
arhythmic intercalation of variegated and redquartz sandstones,
siltstones and argillitesformed in a gradually deepening basin.
Thelower parts of the cycles are represented by red-dish-brown
cross-bedded coarse-grained sand-stones replaced upwards by
interbeddingfine-grained sandstones, siltstones and
argillites.Particularly characteristic of the MatusevichFormation,
but also of the overlying strata, arereddish-brown thin-bedded
fine-grained sand-stones and siltstones. Interbeds of
greenish-greysediments are rare in this interval. The strata ofthe
Matusevich Formation are rich in plant fos-sils and vertebrates.In
the type section on the Matusevich River fiveunits have been
described in the sequence of theMatusevich Formation, viz., from
bottom totop:1) grey coarse-grained sandstones, 35 m;2)
intercalation of red sandstones (dominating),siltstones and
argillites, 240 m;3) red argillites and siltstones with rare
interbedsof sandstones, 150 m;4) red sandstones, 90 m;5)
intercalation of sandstones, siltstones andargillites (dominating),
65 m.In the neighbouring regions (Ushakov,Pod’’emnaya, Bol’shaya
rivers) only some inter-vals of this sequence are represented.
OnKomsomolets Island, the Matusevich Formationis well exposed in
many regions, and may reach470 m in thickness. The heterostracan
Psammosteus cf. maeandrinusAgassiz, 1844, and placoderms
Asterolepis cf.maxima Agassiz, 1844, Bothriolepis cf.obrutschevi
Gross, 1942, B. cf. trautscholdiJaekel, 1927 and B. cf. maxima
Gross, 1933,indicate a Frasnian age for this formation
(Lukševičs 1997, 1999) (Fig. 3). However, in thetype section on
the Matusevich River the typicalFrasnian fauna appears only in bed
2 (seeabove), so it is possible that the lowermost partof the
formation is of late Givetian age(Lukševičs 1999). Bothriolepis cf.
obrutschevifrom the lower part of the formation correlatesthese
strata with the upper Givetian or lowerFrasnian Amata Formation of
the Baltic (Mark-Kurik 1998).Vavilov Formation. The Vavilov
Formation,first identified by Egiazarov (1957), was namedafter the
Vavilov Glacier (southwestern OctoberRevolution Island). Its type
section is located onthe Matusevich River and on its tributaries
(out-crop 18, beds 6-33, and outcrop 18a, lower part;Figs 2; 12).
The lower boundary of the Vavilov Formationcorresponds to the base
of the lowermost bed oflimestones. Characteristic of this formation
isthe dominance of fine-grained sediments –mainly red to variegated
siltstones and argilliteswith interbeds of fine-grained sandstone.
Rareinterbeds of grey limestones with abundantplant remains are up
to 2.7 m thick. The lime-stones are rich in vertebrate remains, and
thin-walled ostracodes are common. The VavilovFormation was formed
during the maximum ofthe Late Devonian transgression. The thickness
of the Vavilov Formation reachesup to 200-300 m on October
Revolution Island,and varies between 150 and 290 m on Komso-molets
Island.A poor vertebrate fauna in the Vavilov Forma-tion does not
allow its precise age-dating.However, considering the ages of the
underly-ing Matusevich Formation (see above), and theoverlying
Mal’yutka Formation (see below), theVavilov Formation is correlated
with theFrasnian (Fig. 3; see also Lukševičs 1999).Mal’yutka
Formation. The Mal’yutkaFormation is named after a tiny glacier
justnorth of the Vavilov Glacier, on the upperreaches of the
Matusevich River (Fig. 1)(Menner et al. 1979). This is the only
regionwhere the strata of the Mal’yutka Formation areknown to be
exposed. The type section of this
Männik P. et al.
118 GEODIVERSITAS • 2002 • 24 (1)
-
formation is located on the Matusevich River(outcrop 18a, upper
part; Figs 2; 12). The lower boundary of the Mal’yutka
Formationcorresponds to the upper surface of the last lime-stone
bed in the underlying Vavilov Formation.In comparison with the
underlying VavilovFormation, the amount of sandstone
increasesconsiderably and limestones are missing in theMal’yutka
Formation. The formation consists ofan intercalation of red and
variegated sandstoneswith interbeds of conglomerates, siltstones
andargillites. At some levels flat nodules of pink gyp-sum are
common. Vertebrate and plant remainsare the only fossils. The
sediments of theMal’yutka Formation were formed in
graduallyshallowing basin. On the Matusevich River,where the Upper
Devonian sequence is mostcomplete in the region, the Mal’yutka
Formationis at least 300 m thick. A new subspecies of the placoderm
Bothriolepisleptocheira Traquair, 1893, occurring in theupper part
of the Mal’yutka Formation, suggestsFamennian age for these strata
(Lukševičs 1999)(Fig. 3). The age of the lower part of this
forma-tion is not known but is assumed to be Frasnian.
CONCLUSIONS
The development of the Silurian and Devoniansedimentation in the
Severnaya Zemlya regionwas affected by both, global eustatic events
andregional tectonics in northern Europe, Urals,and Central
Siberia. Rhuddanian-early Aeronian normal marine car-bonates
(Vodopad Formation) formed duringthe major early Llandovery
transgression.Assemblages of stromatoporoids, corals,crinoids, and
ostracodes from the VodopadFormation indicate not only to the
open-shelfenvironment of sedimentation but also to thegood
connections of the sea in the SevernayaZemlya region with the
Siberian and Timan-Urals but also Baltic basins. In late Aeronian
(Golomyannyj Formation), inconditions of a global regression,
common ele-ments with Baltic faunas became rare or disap-
peared. During the major late Llandovery(Telychian)
transgression (Srednij Formation), inshallow-shelf environments
biostromes and bio-herms flourished in the Severnaya Zemlya
region.Starting from the end of Llandovery, the generaltendency of
the development of sedimentationin Severnaya Zemlya and Sedov
archipelagoswas regressive, with transgressive oscillations insome
periods. Carbonates were replaced by var-iegated and red
terrigenous sediments inLudlow to Přidoli time (Ust’-Spokojnaya
andKrasnaya Bukhta formations). In the lateSamojlovich time,
Severnaya Zemlya evidentlybecame semi-isolated also from the
Siberianbasin (common taxa are found only amongostracodes and
vertebrates), and starting fromthe Ust’-Spokojnaya Formation some
faunalsimilarities are noticed only between theSevernaya Zemlya and
Svalbard sequences(Markovskij & Smirnova 1982). At the end
ofthe Silurian, sedimentation terminated in severalareas in the
Severnaya Zemlya basin and theuppermost Silurian strata were lost
to erosion.In some regions both the entire Přidoli and theupper
Ludlow are missing.Unlike the Silurian, Devonian strata are
domi-nated by variegated terrigenous rocks. Threemain periods,
related to the global eustaticcyclicity, can be recognized in the
Devoniansedimentation on Severnaya Zemlya: 1) after a considerable
gap, and denudation of thelate Silurian sediments, the
sedimentation startedagain in Lochkovian. During the initial stage
ofthe Early Devonian transgression mainly terrige-neous sediments
accumulated (Severnaya Zemlya,Pod’’emnaya and Spokojnaya
formations);2) the transgression reached its maximum in thelate
Pragian-early Emsian (Rusanov and earlyAl’banov) time (the lower
Rusanov Formationis the only interval in the Devonian sequence
onSevernaya Zemlya containing rich and variableopen marine
invertebrate faunas). Based on ver-tebrates, in early Lochkovian
the SevernayaZemlya region had some connections only withthe
northern Europe. In late Lochkovian, thedeveloping transgression
re-opened migrationalways, and in late Pragian-early Emsian
faunas
Silurian and Devonian strata on Severnaya Zemlya
119GEODIVERSITAS • 2002 • 24 (1)
-
became similar in Severnaya Zemlya, Tajmyr,Central Siberia,
Timan-Urals region, NovayaZemlya, and Svalbard; 3) the main part of
the Devonian sequence,starting from the upper Al’banov Formation,
ismainly represented by variegated or red terrige-neous sediments
formed in an extremely shal-low-water epicontinental basin with
abnormalsalinity. Rare thin interbeds of carbonate rocksare found
only at some levels. The vertebrateassociations in these strata
possess some similar-ity to those from Baltic.
AcknowledgementsThe authors are grateful to A. Abushik,I.
Evdokimova, V. Karatajūtē-Talimaa,E. Lukševičs, E. Mark-Kurik, T.
Modzalevskaya,T. Märss, H. Nestor and J. Valiukevičius forvaluable
comments on biostratigraphy. A. Noormade linguistic improvements to
the manuscriptand O. Hints assisted in scanning the figures.The
manuscript was much improved followingthe comments of referees A.
Blieck and G. C.Young. The study by P. Männik was supportedby grant
No. 3749 of the Estonian ScienceFoundation and by governmental
research grantNo. 0330360s98.
REFERENCES
ABUSHIK A. F. 1982. — Ostracodes from theSamojlovich Formation,
and from the Wenlock-Ludlow boundary interval on Severnaya
Zemlya,in KABAN’KOV V. YA. & LAZARENKO N. P. (eds),Geologia
Arkhipelaga Severnaya Zemlya. PGO“Sevmorgeologiya”, Leningrad:
80-102 (inRussian).
ABUSHIK A. F. 1999. — Silurian ostracodes‚ inMATUKHIN R. G.
& MENNER V. V. (eds)‚Stratigrafiya silura i devona
arkhipelagaSevernaya Zemlya. SNIIGGiMS‚ Novosibirsk:89-94 (in
Russian).
ABUSHIK A. F. in press. — The Silurian ostracodesfrom Severnaya
Zemlya. Geodiversitas.
ABUSHIK A. F. & EVDOKIMOVA I. O. 1997. — Keyintervals for
ostracod correlation in different faciesof the Lower Devonian of
the Eurasian Arctic, inIVANOV A., WILSON M. V. H. & ZHURAVLEV
A.(eds), Palaeozoic strata and fossils of the EurasianArctic.
Ichthyolith Issues Special Publication 3: 3-4.
ABUSHIK A. F. & EVDOKIMOVA I. O. 1999. —Lagoonal to normal
marine Late Silurian-EarlyDevonian ostracode assemblages of the
EurasianArctic. Acta Geologica Polonica 49, 2: 133-143.
AFANASSIEVA O. B. & KARATAJŪTĒ-TALIMAA V.1999. —
Osteostracans from Severnaya ZemlyaArchipelago, in MATUKHIN R. G.
& MENNER V. V.(eds), Stratigrafiya silura i devona
arkhipelagaSevernaya Zemlya. SNIIGGiMS, Novosibirsk:137-139 (in
Russian).
DIBNER A. F. 1982. — The age of the Carboniferousand Permian
terrigenous sediments from theSevernaya Zemlya Archipelago by
palynologicaldata, in KABAN’KOV V. YA. & LAZARENKO N. P.(eds),
Geologiya arkhipelaga Severnaya Zemlya.PGO “Sevmorgeologiya”,
Leningrad: 124-129 (inRussian).
EGIAZAROV B. KH. 1957. — Geological description ofSevernaya
Zemlya Archipelago, in MARKOV F. G.& NALIVKIN D. V. (eds),
Geologiya SovetskojArktiki. Trudy NIIGA 81: 388-429 (in
Russian).
EGIAZAROV B. KH. 1959. — The geological structureof the
Severnaya Zemlya Archipelago. TrudyNIIGA 94, 138 p. (in
Russian).
EGIAZAROV B. KH. 1970. — Severnaya Zemlya, inTKACHENKO B. V.
(ed.), Ostrova SovetskojArktiki. Geologiya SSSR 26. Nedra, Moscow:
237-323 (in Russian).
EGIAZAROV B. KH. 1973. — Severnaya Zemlya, inNALIVKIN D. V.,
RZHONSNITSKAYA M. A. &MARKOVSKI B. P. (eds), Devonskaya
systema, vol-ume 2. Nedra, Moscow: 148-152 (in Russian).
EVDOKIMOVA I. O & ABUSHIK A. F. in press. — TheEarly
Devonian ostracodes from SevernayaZemlya. Geodiversitas.
GURARI F. & KRASILOV V. 1982. — Decisions of theAll-Union
Meeting on the Elaboration of UnifiedStratigraphical Schemes for
the Pre-Cambrian,Palaeozoic and Cenozoic Strata in Central
Siberia(1976). Nauka, Novosibirsk, 130 p.
JOHNSON M. E., TESAKOV YU. I., PREDTECHENSKIJ N.N. & BAARLI
B. G. 1997. — Comparison of LowerSilurian shores and shelves in
North America andSiberia, in KLAPPER G., MURPHY M. A. &
TALENTJ. A. (eds), Paleozoic sequence stratigraphy,
bios-tratigraphy, and biogeography: studies in honor ofJ. Granville
(“Jess”) Johnson. Geological Society ofAmerica Special Paper 321:
23-46.
KABAN’KOV V. YA., ROGOZOV YU. G. & MAKAR’EVA. A. 1982. —
Stratigraphy of the UpperProterozoic strata of the Bol’shevik
Island(Severnaya Zemlya Archipelago), in KABAN’KOVV. YA. &
LAZARENKO N. P. (eds), Geologiyaarkhipelaga Severnaya Zemlya. PGO
“Sevmor-geologiya”, Leningrad: 5-21 (in Russian).
KARATAJŪTĒ-TALIMAA V. & BLIECK A. 1999. —Heterostracans, in
MATUKHIN R. G. & MENNER V.V. (eds), Stratigrafiya silura i
devona arkhipelaga
Männik P. et al.
120 GEODIVERSITAS • 2002 • 24 (1)
-
Severnaya Zemlya. SNIIGGiMS, Novosibirsk:127-131 (in
Russian).
KARATAJŪTĒ-TALIMAA V. & MÄRSS T. in press. —Upper Silurian
thelodonts of Severnaya ZemlyaArchipelago. Geodiversitas.
KHAPILIN A. F. 1982. — Stratigraphy of Devoniansediments of
Severnaya Zemlya Archipelago, inKABAN’KOV V. YA. & LAZARENKO N.
P. (eds),Geologiya arkhipelaga Severnaya Zemlya.
PGO“Sevmorgeologiya”, Leningrad: 103-119 (inRussian).
KLUBOV B. A., KACHANOV E. I. & KARATAJŪTĒ-TALIMAA V. N.
1980. — Silurian and Devonianstratigraphy of Pioneer Island
(Severnaya Zemlya).Izvestiya Akademii Nauk SSSR,
SeriyaGeologicheskaya 11: 50-56 (in Russian).
KURIK E. YU., KURŠS V. M., MARKOVSKIJ V. A.,MATUKHIN R. G.,
MENNER V. VL.,MODZALEVSKAYA T. L., PATRUNOV D. K.,SAMOJLOVICH YU.
G., SMIRNOVA M. A., TALIMAAV. N., KHAPILIN A. F., CHERKESOVA S. V.
&ABUSHIK A. F. 1982. — To the Silurian andDevonian stratigraphy
of Severnaya Zemlya, inYUFEREV O. V. (ed.), Stratigrafiya i
paleontologiyadevona i karbona. Nauka, Moscow: 65-73
(inRussian).
LUKŠEVIČS E. 1997. — Preliminary report onMiddle/Upper Devonian
fishes from SevernayaZemlya (Placodermi, Bothriolepididae), in
IVANOVA., WILSON M. V. H. & ZHURAVLEV A. (eds),Palaeozoic
strata and fossils of the Eurasian Arctic.Ichthyolith Issues
Special Publication 3: 24-25.
LUKŠEVIČS E. 1999. — Placoderms (Antiarchi)‚ inMATUKHIN R. G.
& MENNER V. V. (eds)‚Stratigrafiya silura i devona
arkhipelagaSevernaya Zemlya. SNIIGGiMS‚ Novosibirsk:142-146 (in
Russian).
MARK-KURIK E. 1991. — Contribution to the corre-lation of the
Emsian (Lower Devonian) on thebasis of placoderm fishes. Newsletter
inStratigraphy 25: 11-23.
MARK-KURIK E. 1998. — Placoderms in the Lowerand Middle Devonian
of Severnaya Zemlya, inGINTER M. & WILSON M. V. H. (eds),
Circum-Arctic Palaeozoic faunas and facies. IchthyolithIssues
Special Publication 4: 33-35.
MARK-KURIK E. 1999. — Arthrodires, in MATUKHINR. G. & MENNER
V. V. (eds), Stratigrafiya silurai devona arkhipelaga Severnaya
Zemlya .SNIIGGiMS, Novosibirsk: 139-142 (in Russian).
MARKOVSKIJ V. A. & SMIRNOVA M. A. 1982. —Silurian sediments
of Severnaya Zemlya Archi-pelago, in KABAN’KOV V. YA. &
LAZARENKO N. P.(eds), Geologiya arkhipelaga Severnaya Zemlya.PGO
“Sevmorgeologiya”, Leningrad: 39-60 (inRussian).
MATUKHIN R. G., ABUSHIK A. F., VALIUKEVIČIUS YU.YU.,
KARATAJŪTĒ-TALIMAA V. N., KURIK E. YU.,KURŠS V. M., MARKOVSKIJ V.
A., MENNER V. VL.,
MODZALEVSKAYA T. L., SAMOJLOVICH YU. G.,SMIRNOVA M. A. &
CHERKESOVA S. V. 1982. —Silurian and Devonian boundary and the
boundarybeds on Severnaya Zemlya, in KRASNOV V.I. (ed.),Granitsy
krupnykh podrazdelenij fanerozoyaSibiri. Sbornik nauchnykh trudov
SNIIGGiMS,Novosibirsk: 77-95 (in Russian).
MENNER V. V., MATUKHIN R. G., KURŠS V. M.,TALIMAA V. N.,
SAMOJLOVICH YU. G. & KHAPILINA. F. 1979. — Lithofacial
peculiarities of theSilurian-Devonian sediments of Severnaya
Zemlyaand north-western Siberian Platform, in MATU-KHIN R. G.
(ed.), Litologiya i paleogeografiyaSibirskoj platformy. Trudy
SNIIGGiMS 269: 39-55 (in Russian).
MENNER V. VL., SMIRNOVA M. A. & CHERKESOVAS. V. 1982. —
Structure and age of the RusanovFormation (Severnaya Zemlya
Archipelago), inKABAN’KOV V. YA. & LAZARENKO N. P.
(eds),Geologiya arkhipelaga Severnaya Zemlya. PGO“Sevmorgeologiya”,
Leningrad, 123 p. (inRussian).
MODZALEVSKAYA T. L. 1999. — Brachiopods‚ inMATUKHIN R. G. &
MENNER V. V. (eds)‚Stratigrafiya silura i devona
arkhipelagaSevernaya Zemlya. SNIIGGiMS‚ Novosibirsk:100-105 (in
Russian).
MODZALEVSKAYA T. L. in press. — Silurian andDevonian brachiopods
from Severnaya Zemlya.Geodiversitas.
MÄNNIK P. 1997. — Silurian conodonts fromSevernaya Zemlya, in
IVANOV A., WILSON M. V.H. & ZHURAVLEV A. (eds), Palaeozoic
strata andfossils of the Eurasian Arctic. Ichthyolith IssuesSpecial
Publication 3: 25-26.
MÄNNIK P. 2002. — Conodonts in the Silurian ofSevernaya Zemlya
and Sedov archipelagos (Russia),with special reference to the genus
OzarkodinaBranson & Mehl, 1933. Geodiversitas 24 (1):
77-97.
MÄRSS T., FREDHOLM D., TALIMAA V., TURNER S.,JEPPSSON L. &
NOWLAN G. 1995. — Silurian verte-brate biozonal scheme, in LELIÈVRE
H., WENZ S.,BLIECK A. & CLOUTIER R. (eds), PremiersVertébrés et
Vertébrés inférieurs. Geobios M.S. 19:369-372.
MÄRSS T. & KARATAJŪTĒ-TALIMAA V. in press. —Ordovician and
Lower Silurian thelodonts fromSevernaya Zemlya. Geodiversitas.
NIKIFOROVA O. I. & MODZALEVSKAYA T. L. 1968. —Some
Llandovery and Wenlock brachiopods fromthe north-western part of
Siberian Platform.Uchenye zapiski NIIGA 21: 50-81 (in Russian).
SHURYGINA M. V. & SYTOVA V. A. 1999. —Rugose corals‚ in
MATUKHIN R. G. & MENNERV. V. (eds)‚ Stratigrafiya silura i
devona arkhi-pelaga Severnaya Zemlya . SNIIGGiMS‚Novosibirsk: 86-89
(in Russian).
STUKALINA G. A. 1999. — Crinoids‚ inMATUKHIN R. G. & MENNER
V. V. (eds)‚
Silurian and Devonian strata on Severnaya Zemlya
121GEODIVERSITAS • 2002 • 24 (1)
-
Stratigrafiya silura i devona arkhipelagaSevernaya Zemlya.
SNIIGGiMS‚ Novosibirsk:105-110 (in Russian).
SMIRNOVA M. A. 1982. — The first finds of lateSilurian tabulates
on Severnaya Zemlya, inKABAN’KOV V. YA. & LAZARENKO N. P.
(eds),Geologiya arkhipelaga Severnaya Zemlya. PGO“Sevmorgeologiya”,
Leningrad: 61-79 (in Russian).
VALIUKEVIČIUS J. 1999. — Acanthodians‚ inMATUKHIN R. G. &
MENNER V. V. (eds)‚Stratigrafiya silura i devona
arkhipelagaSevernaya Zemlya. SNIIGGiMS‚ Novosibirsk:131-137 (in
Russian).
VALIUKEVIČIUS J. in press. — Devonian acantho-dians from the
Severnaya Zemlya Archipelago.Geodiversitas.
Submitted on 13 April 1999;accepted on 30 October 2001.
Männik P. et al.
122 GEODIVERSITAS • 2002 • 24 (1)