CC BY
116
УДК 551.76/.77:551.351.2(265.2-16)
P.F. Gozhik1, N.V. Maslun1, M.M. Ivanik1, L.F. Plotnikova1,
L.N. Yakushin1
STRATIGRAPHIC MODEL OF THE MESOZOIC AND CENOZOIC OF THE WESTERN BLACK SEA BASIN
Detail stratiphication of the Mesozoic and Cenozoic of the Western Black Sea Basin has been carried out on the base of biostratigraphic, litholog-ical, geophysical and seismic stratigraphy methods, and interpretation of the available data. Stratigraphic charts of the Mesozoic and Cenozoic deposits have been created. Sections are working out in detail and the peculiarities of the spatial and temporal structure of productive Mesozoic and Cenozoic deposits complex is taking into account. Regional stages, series, formations and packets have been allocated. Their correlation with International Stratigraphic Chart has been established. Their differences and similarities are demonstrated on the base of the correlation of Mesozoic and Cenozoic deposits of the northwestern shelf of the Black Sea.
The Mesozoic-Cenozoic sedimentary complex of the Western Black Sea Basin (WBSB) is represented by the Quaternary (1-3 km), Pliocene (0,51,2 km), Oligocene-Miocene (3-5 km), Paleocene-Eocene (34 km) and Cretaceous deposits of 16-km total thickness. This sedimentary complex has rather complicated structure and during its existence underwent numerous rebuilding of tectonic plans, inheritance of superimposed structures and inverse movements. The thickness of the Cenozoic deposits, which fill the deep-sea basin, gradually decreases from the center to its edges. The flexure amplitude of the bedding surface increases from recent sediments to old ones: for the base of the Quaternary it does not exceed 2 km, for the top of Maikopian it is 3-4 km, for the Eocene — 5-6 km, and for the base of Paleogene — 7-8 km. Undoubtedly, this points to a long-term and gradual, on the whole, consedimentary downwarping of the basin during the Cenozoic. Adjacent to the continental slope of the Western Black Sea Basin with its shelf occurs in the 100-200 km interval (Odessa area) and has a complicated geologic structure.
The Alpine structural-formation complex consists of the Krylovsky Trough, Kiliya-Zmeiny Uplift Zone, Marginal Escarpment, Karkinita — Northern Crimean Trough, and Kalamita — Central Crimean Uplift Zone (fig. 1).
The structure of the Mesozoic-Cenozoic sedimentary complex is of special interest, because sediments of the Lower and Upper Cretaceous, Paleocene, Maikopian and Neogene are promising for gas and oil. Thus, in the Karkinita North Crimean Trough the most part of explored and supposed hydrocarbon reserves is concentrated.
©P.F. Gozhik, N.V. Maslun1, M.M. Ivanik1 ,L.F. Plotnikova1, L.N. Yakushin1
1 Institut of geological sciences NAS Translated by Yu. Chernenko
D'SMi'rtna ЗДИшп
Western Black sea basin Fig. 1. Tectonic map and seismic section of the Northwestern Black Sea (by “Sevmorneftegeofizika” [10])
Considerable thickness of sedimentary deposits, presence of clayey-carbonaceous rocks, reservoir rocks, fluid traps and structural forms determine a high resource potential of the region.
Taking into consideration the riftogenic nature of the Black Sea Basin, considerable thickness of sediments and favorable conditions for hydrocarbon accumulation, we can consider the continental slope also to be highly promising.
In this aspect, a creation of a chronostratigraphic model of the Mesozoic -Cenozoic sedimentary complex of the Black Sea shelf and continental slope,
ІІ
GENERAL
STRATIGRAPHIC
SCALE
REGINAL
STRATIGRAPHIC
DIVISIONS
NORTHWESTERN SHELF OF THE BLACK SEA
CORRELATION OF ADJACENT SECTIONS
< -
2
£
s
<
cj
ZONAL SCALES
AMMONITES
Curopa
(Coord. J Thlertl, J. Hancock. Ph Moede-mecknr. P.Amedro, L.G.. Uulot)
Terminus
■ft&.qo__________
Fresvl lien sis
Neuberglcus/ Trldens ?/ Epiplcctus
Ro I yp locum
M O.UO
Delawa rensls Hippocrepls III
Bidorsatum
Gallicus / Toxanus
Serratomarglnus
TVIdorsatum
Petrocorlensls
Coloradoense
PLANKTON FORAMINIFERS
ZONES
FORAMINIFERS
Abathomphalus
myaroensls
Abathomphalus myaroensls, Conlcotruncana con lea, Pscudotextutarla variant, Oollvinoldcs draco, Bollvina incrnstaca
Gansserina
gansserl
Globotruncanlta
stuarti,
Gansserina
gansserl
Globotruncana
Globotruncandla havflncnsls
Globotruncanlta _____calcarata
Globotruncanella havanensls, Globotruncana morozovae, Bollvina Incrassata
Globotruncana
ventrlcosa
Globotruncana
ventrlcosa,
Brotzenella
monterelensls
Globotruncanlta
elevata
Globotruncanlta
elevata,
Gavelinella
dalnae
Globotruncana
fornicate,
Gavelinella
-----atclilacra____
D. asymetrlca
Bolivinoides
strlglllatus
Gavelinella
Infrasantonica
Dlcarinella
concavata
Gavelinella
thalmannl,
Dlcarlnella
concavata
Stensloina
granulata
Govallnulla ammonoldo
LONES
NANNOPLANKTON
Olympic District (Marginal Bcnch)
Nephrolithus
frequens
UCbrapbiditos
quadratus,
Marcatlus
ПІВІІЮПВЦ
Unlplanarlus
trlfydus
District Of Framing Structures in the Karkinita Trough
W4AA
Soquooceb Of Cmy andS dayey fcmo-' atoпи : if» th boiewth N«
prvoirjvui I,
quena.
Umostooes. nr rt*. an places •«•ma ling, leij often «intones
Gtobotruncantta sh*art (Lapp.), Ganssenna psnsen (8©»o and ільгарліліе» qvadratus.
46-270 m
Brolnsonia parca constrlcta
Sequence of biomorphic- J Sequence of limestones. d«!rt!al limosloncb. incqui-S marls, less often granular sandstones with 4 jntertayeringmarls Globorotatitos emdyensis Vass. Gtobotruncona mo-
rozovae. (Vass.). воілгіпа incrassalo, (Rss). Broin-son in partta constrtcta
Brolnsonia parca parca
> and limestonos with < Globotruncanella v havanensis (Woorw.). Globotruncana moro-(Vass.), Globo-rotalites emdiensis (Vass.), Bro*nsonia parka constricta. Broinsonia parca parca
Up to 375 m
Arkhangelsklella
cymbiformis
Sequenco of forammiforal iimos’.onos. inoqu.granular sandstoros with Cibiador. tomironsis (Vass.), ArVha-ngolskiella cymbifocmis
101 m
Luclanorhabdus cayeuxil
Mlcula
staurophora
Elffelltbus
exlmlus
—ru*T$rm3rmver*ay-
sognMintatum I Kemptnerlu»
maowiricun
Karkinita District (flcxuring zone)
Plain Crimea (North Crimean District, Northwestern Subdistrict)
Sequence of режупофЛс fractured imesUftcs. Often inc*iiayering tomi-Mono*, mart* someuwes s*tstoocs and mjdstones w«*< A&aincmpfiaioi mayafocnji* (Bon). Psoudotertutana vanans (R/ehak). ©cbotfuncamia stuani (Lapp). Nepiwort frequent. LrtN-apfwo *s quadratus. Marcaimt піфіtenae
128-500 m
S«<jjence of dayey fradured lime-stones with Gtototancara vcntnco-sa (WKc). Globotruncana morozovae (Vws.). Brotzene'ia mortettfensis Marie. BoWina incrassata (Rss.). B. Kalin n(Vass.). Gromsoria parca parca, Brcinsono parca constricts 72-600 m
Sequence of pelitonorphtc bird limestones with Globotruncana elevau (Broil). Gavelinella dtiaie Myall
Up I» 220 m
О
d
CD
sz
N
Q
Sequence of pelrtomorphic micrograined limestones wit Gavelinella infrasantonica (Baiakhm.), Gavelinella steliigefa (Marie). Globotruncana fornicate (Piumm). Lucianortiabdus caveuxii________Up to 220 m
Soquonco of pelitomo-rphic hard limestones, sometimes marblo-liko, with Dicarinella concavata (Brotz.). Stensloina granulata Olb.. Gavolmolla thalmanni(Brotz-) Mlcula staurophora
83-305 m
Upper subsuite Grey marls with interlayers of clayey limestones, lenses of flinty rocks with Abathomphalus mayaroensis (Bolli), Pseudotextularia varians (Rzehak)
Up to 900 m
Lower subsuite Grey clayey marls with marl and clay interlayers, with Bo-livina kalinini (Vass.). Bolivina incrassata (Rss.), Brotzenella monterelensis (Marie).
Up to 450 m
Light gray and whlto limestones, dayey with marl intorlayors. with Gavelinella dajnae Myatl. Cibicidoies temironsis Vass. - in top, Gavollnella stclligcra (Mario) - In base
up to 170 m
Light grey and white limestones, clayey, silicified. with sutures and stylolites, with Gavelinella infrasantonica Balkhm ______________________________Up to 200 m
Light grey and whit© limestones clayey, flinty, with sutures and stylolites,in places porcelainlike, with clay interlayers, with Stensioina granulata Olb. - in top, Globotruncana lapparenti (Brotz.) - in base.
Up to 1200 m
ОС as.aa W. archaeoc retacea LlngulogavGllnella
' 8: =3 Navlculare / globosa cbiastia
Pentagon um cushmanl Rotallpora
Rofcnllporo relchell
2 Rhotomagcnsc acutus
5 Rotallpora relchell
о cm Ш Olxonl Rotallpora globotruncanoldes Rotallpora globotruncanoldes Rotallpora Gartnerago segmentatum
H О Mantelll Gavellnella cenomanlca Elffellthus turrlseiffellli
J 8 Rotallpora Rotallpora appenlnnlca
4 Dispar appennlnlca
(Г Schackolna Octocyclus
И ш Q. R. tlclnensis Rtallpora tlclnensls, R. subtlclncnsis,
m LL ZD Inflatum R. subtle! nensis Ceratollthlum hamata
4 Tlcinella
xoa.iA^utu*
CQ Hedbergella planisplra, Gavellnella Intermedia, Tlcinella digitalis
—1 < MIDDLE Lorlcatus 105.?
Dentatus primula
ОС Hedbergella planispira
$ Hedbergella planisplra
ULS T&rdefurcata
cr Ш Jacobi i i i T. bejaouaensls Gavellnella intermedia.
LL Nolanl
P. cheniourensls
< f- (X. UJ —i Q Melchlorls <3. algerianus GloPlgerlnelloldes algerianus,
Subnodoso- Leupoldina
117 costa turn G. ferreolensis protuberans
48.6 ^rcota Leopoldlna Hedbergella
„„Posbayesi cabrl
aptica, Gavellnella suturalis
О —i 120 WelSSl
ЛУ Tuarkyricus
Su<;uonco of Umy-cknyoy aittatonos, snnds with Ro-Inlipora ticlnensia (Gand.), Octocycius roinhardtll. Ortoitotinldao
162 м
Clay seguonco with Gavelinella intermedia (Berth.). Hedbergella planispira Tapp.
layorlnQ of of limy silty clny-n nod allitionot wlin Gnvollnolln Intor-madln (Borin.). O oW-garinnlladeii «''joit/inun .^aupoldlnn protubarana
(Dolll> to Ort>ltollnidn«
Soquonc® of limy cioysorvd siltstonor. with Moti»orgoMa opuca (Agnl.) and Gavolino-llo no turn-is (Myall.)
Sequence of sandstone and limostones. at NW mainly marls, in places mudstones with Rotal po-ra globotruncanoldes (Sig.), R. broteori (Sig.), R. Reicholi (Mom.). R. cushmani (Morr.). Eiffelithus tunisoiffellii, Gartners do sog-segmetatum, Uthrathldi-tes acutus, Orbitolinldae etc.
300 m
Soquonco of mainly Umo stonoa and sandstones. in pfacos tuffs and volcanic rocks with Rotallporn appo-nninlca (Ron*.), R. llci^onsu (Gnnd ). R Subtiononsis (Gand.). CopatolnhKim ho-rrota. Holtcolitnus troboculo
Sequence of llmestonos. ciayey marls with Rotalipo-ra appeninica (Renz.), R Brotzeni
400-660 m
Sequence & Nock and dark groy limostones with Ro’av.pow uppo nninlca (Renz.). R. ttorvensis (Gand.). Eiffelithus tunssoiffo-
^ 25
fa
Upper subsuite Dark gey clayey marls, in places with limestone interlayers, with Rotallpora cushmani (Morr.) Up to 300 m
Middle subsuite
Clayey marls with Rotalipora appenninica (Renz.)
Up to 300 m
11
Oroy mono v
1 Kotnllporn tlcmonsle л (Ren*.; up to a:
MuOAlciw>, in piacos votcanJditaOc rocka wltr Praoplobotruncaria dotooonsl* (Pfumm.). Pla-oomoiino buKtorfl (Oand.)_________Up to 300
L-- v. »•«•» г-.I»-. ГЧ ро<ро!упчс1>е, In (Uc«t гм(у «окл'вв»
"*» P«M«^lu*U uAMUU (Р»М )
ЦДШЯ
Dark grey mudstones, easy limy with siltstone interlayers, near volcanoes volcanogenic rocks with Hoptites den tatus (Sow.) Etc.
Up to 560 m
Dark grey siltstones with mudstone interlayers, in places effusives with Hedbergella trocoidea Gand
Up to 170 m
Dark grey siltstones, non-hmy and easy limy, siltstones, in base in places gravelstones with Hypacanthoplites jacobi
Up to 200 m
Grey-colored quartz sandstones, limy siltstones. mudstones, gravelstones. in places limestones with Palorbitolina ienticularis (Blum)
Up to 200 m
LOWER
Fig. 2. Regional stratigraphic chart of the Cretaceous deposits of the Black Sea northwestern shelf
reconstruction of sedimentation evolution, determining of space-time regularities of the facies distribution of especially productive rock masses, acquires a special importance as a basis for sedimentary and lithogeodynamic models.
The analysis of modern stratigraphic data testifies to the heterochronism and heterogeneity of the Black Sea northwestern shelf and adjoining continental slope. The Mesozoic sequence is represented by three systems. The stratigraphy of the Triassic and Jurassic is not studied well enough, but that of the most spread Cretaceous and Cenozoic deposits, due to their perspectivity, is studied better. On the continental slope, the Triassic-Lower Jurassic deposits are represented by terrigenous-flysch and flysch-like facies, those of the Middle Jurassic — by interbedding of sandstones, siltstones and mudstones with gravellites and tufas, and those of the Upper Jurassic
— predominantly by deep-gray argillites, organic limestones, marls, and clays. The Lower Cretaceous sediments of the northwestern shelf and continental slope are characteristic terrigenous and clayey rocks, and the Upper Cretaceous deposits are characteristic carbonate rocks. Preliminary interpretation of geologic-geophysical evidences and detailed paleontological and lithological study of Cretaceous-Cenozoic sediments of the shelf anticline uplifts proved a complicated mosaic structure of the Cenozoic lithofacial complexes.
To develop a stratigraphic model, the available biostratigraphic data on various fossil groups was considered, core samples were reinterpreted on microfaunal evidences, the actual paleontological base was analyzed, and stratification of the Mesozoic-Cenozoic sections was revised for all structures of the NW shelf and adjacent territories. At this, biostratigraphic data were correlated with lithological and geophysical evidences.
The created regional stratigraphic schemes of the Cretaceous, Paleogene, Neogene, and Quaternary systems and recognized main development stages of the NW shelf of the Black Sea are based on the integral analysis of geological-geophysical data and comprehensive stratigraphic division of the Mesozoic and Cenozoic sediments [3-6, 10, 15, 19, 26, 29, 40-42]. The correlation with coeval formations of adjacent regions shows similar and different features of the NW shelf and another structures of the Crimean-Caucasian region.
MESOZOIC. CRETACEOUS SYSTEM. For the stratigraphic division of the Cretaceous of the NW Black Sea shelf and development of stratigraphic schemes, the international “biological” standards were used, which were incorporated into the chronostratigraphic scheme of Western Europe [13]. To determine the limits of stratigraphic divisions, standard logging data were used too.
The oldest sediments penetrated by boreholes on the NW Black Sea shelf are the Lower Cretaceous rocks. They were drilled in the small number of boreholes. The most complete section of the Lower Cretaceous formations (Barremian-Albian) was found only in one borehole — 01impiyska-400. The rest of boreholes, as re-interpretation of the available data demonstrated,
were stopped in the Upper Albian rocks (another investigators dated those formations as Triassic or Jurassic) (fig. 2).
The Upper Cretaceous sediments are drilled almost in all structures of the NW Black Sea shelf.
Three structural-facial districts (SFD) are recognized on the NW Black Sea shelf on the features of stratigraphic and lithological composition and development character (see the Scheme): Olimpiysky, Framing structures of the Karkinita Trough, and Karkinita Trough. The boundaries of the districts are of tectonic nature.
The Olimpiysky SFD occupies the western part of the Marginal Escarpment in the western part of the shelf. In its boundaries, the Lower Cretaceous sediments are represented by the Upper Barremian, Lower and Middle Aptian, Middle (?) and Upper Albian, sedimentation breaks are in the Late Aptian and Early Albian. The Upper Cretaceous sediments are the Lower and Upper Campanian. Sedimentation breaks are in the Cenomanian, Turonian, Coniacian, Santonian, and Maastrichtian.
The Framing structures of the Karkinita Trough SFD includes the Kalamita Rampart and a number of uplifts (Odessa, Bezimenne, Flangove, Karkinita, Southern Flank, Eupatoriav etc.), which are different in the completeness of the cretaceous section [7, 10]. The Lower Cretaceous formations are represented by the Upper Albian (microfaunal zones Rotalipora appenninica, R. ticinensis and R. subticinensis. The Upper Cretaceous sediments are rocks of the Lower Cenomanian, Campanian and Maastrichtian. Sedimentation breaks are in the Turanian, Coniacian, and Santonian.
The Karkinita SFD occupies properly the Karkinita Trough. The Lower Cretaceous sediments are there the Middle and Upper Albian (zones Rotalipora appenninica and R. ticinensis). The Lower cretaceous formations in that district are of all ages of the Upper Cretaceous. A sedimentation break of tectonic nature is observed at the boundary of the Upper Cenomanian — Lower Turonian; it is a rather thick redeposited sequence (up to 100 m).
LOWER CRETACEOUS. The Lower Cretaceous sediments are composed mainly of terrigenous rocks, at some stratigraphic level with significant content of tuffaceous and volcanogenic matter. The boreholes penetrated over 1,000-m thickness. In the majority of the sections, the detailed stratigraphic division is possible at the level of stages and zones.
The most complete section of the Lower Cretaceous in the district and within the NW Black Sea shelf is drilled by b/h 01impiyska-400 that is situated in the western part of the Marginal Escarpment. The Barremian, Aptian and Albian rocks, which lithological composition is mostly similar to those in Fore-Dobrogea, represent it [2, 24].
On the rest of the shelf that is probably bounded from the Olimpiysky SFD by the Odessa Fault, the Upper Albian rocks are drilled mainly.
Barremian stage. The Barremian sediments on the NW Black Sea shelf are recognized only in the Olimpiysky District; their total thickness is 650 m.
The lower portion of the Upper Barremian consists of dark grey to black non-carbonaceous mudstone with 3 Conorotalithes cf. bartensteini Bet
t., C. aff. sigmoicostus Dam, Gauelinella cf. barremiana B e 11., Lamarcina cf. lamplugi (S c h e r 1.), Ophtalmidium cf. gaultinum Dam, Quinqueloculina minima Tapp., Globuligerina cf. tardita (A n t).
The upper part of the Upper Barremian is interlayering limy siltstone, limy-silty clay, silty limestone with foraminifers Lenticulina cf. eichenbergi B a r t. et B r a n d., Globuligerina tardita (A n t.), Gauelinella barremiana B e t t. and nannoplankton Micrantholithus obtusus, Discorhabdus ignotus, Manivitella pematoidea, Lithraphidites carniolensis, Braarudosphaera regularis, Nannocomus sp.
Aptian stage. The Aptian sediments in the considered region are represented by two substages — Lower and Upper. The Lower one consists of limy clay, siltstone, limestone with foraminifers Gavelinella suturalis (M y a 11.), Hedbergella aptica (A g a 1.). Over, a thin interlayering occurs — silty clay and clayey-limy siltstones with foraminifers Gavelinella cf. intermedia (B e r t h.), Leupoldina cf. protuberans (Boll i), Globigerinelloides algerianus (D a m) and Orbitolinidae.
These sediments transgressively covers the Barremian sediments and are overlaid by the Middle Albian rocks with break.
Albian stage. The Albian sediments are widespread on the NW Black Sea shelf and adjacent territories. They are represented by terrigenous-carbonate formations, less often by volcanogenic and volcanogenic-sedimentary. Their thickness increases southward from few meters to 530 m in the Odessa Fault zone. Almost everywhere they transgressively occur over older rocks. They are covered (conformably or with break) by the Cenomanian deposits, less often younger rocks.
Till the last time the age of these sediments was disputable on geological and geophysical data — from Jurassic to Albian. Our investigations have shown and faunistically proved that they belong to the Upper Albian.
UPPER CRETACEOUS. The Upper Cretaceous deposits are widespread on the NW Black Sea shelf. All six stages represent them. The rock composition is mainly carbonate, and in the top and especially in the bottom of section often terrigenous. Their thickness ranges between hundreds to 2,000 m. The three-member division is reliably proven for the Campanian and Cenomanian stages. In some cases zones are recognized, less often an undivided sequence of large stratigraphic volume [25 et al].
Cenomanian stage. Cenomanian sediments are widespread in the region under consideration. They are marl, limestone, sandstone, which transgressively, less often without break occur over Upper Albian deposits and mostly discordantly are covered by the Turonian rocks Their thickness varies from terms of meters (near northern margin of the shelf up to 658 m in the Mikhailovka Depression.
The stage volume is mainly reduced. Only in the deepest parts of the mentioned above depression all three substages can be recognized.
Turonian and Coniacian stages. The Turonian stage is composed of light grey solid limestone, fractured, with Marginotruncana schneegansi B o 1 1 i, Praeglobot rune ana imbricata (M o r n.) and Eiffilithus eximius. The
Turonian sediments with discordance (probably, tectonic) occurs on the Upper Cenomanian rocks and with break under Upper Coniacian ones.
The Coniacian sediments form a sequence of light grey massive limestone, fractured, with sutures and stylolites. They contain the typical Coniacian nannoplankton species, Micula staurophora and Upper Coniacian foraminifers Gavelinella infrasantonica (B a 1 a k h m.) etc.
Santonian stage. These rocks within NW Black Sea shelf are light grey porcelain-like easy silicified limestone with Gavelinella infrasantonica B a 1 akhm., Stensioina granulata granulata (O 1 b.), S. cf. granulata perfecta Koch., Osangularia whitei whitei C a r b. and Lucianorhabdus cayeuxii. The maximum thickness of the Santonian deposits is about 628 m. The Santonian rocks mostly conformably rest over the Coniacian and are covered by the Campanian.
Campanian stage. The Campanian rocks occur over large areas on the NW Black Sea shelf. They are mainly limestones with foraminifers Globorotalites emdyensis V a s s., Cibicides aktulagayensis V a s s., Brotzenella cf. menneri (K e 1 1.), Globotruncana morozovae V a s s. and nannoplankton Broinsonia parca constricta and Prediscospaera stovery. The deposits discordantly cover the Upper Santonian and are overlaid, conventionally, by the Paleocene formations.
Their thickness is about 600 m. The Campanian rocks form three substages, the Middle and Upper ones are most spread. In both cases, two-member division is possible.
Maastrichtian stage. These sediments are also widespread on the NW Black Sea shelf. They are various limestones, less often marl and limy sandstone, or interbedding of those rocks with foraminifers Rugoglobigerina rugosa Orb., Pseudotextularia varians R z e h., Angulogavelinella caucasica V a s s. and nannoplankton Uniplanarius trifidus and Nephrolithus frequens. The maximum known thickness is 450 m [23].
CENOZOIC. PALEOGENE SYSTEM. PALEOCENE. The Belokamenkian regional stage (Lower Paleocene, Danian) is defined in the Paleocene, which consists of the Gromovo suite with two subsuites: lower and upper ones [10, 18, 23]. By plankton foraminifers and nannoplankton, the age of the stratons is substantiated, and a correlation is made with divisions of the International Stratigraphic Scale. It has been proved that the Belokamenkian regional stage is diachronous: the Early Paleocene — the dawn of the Late Paleocene. The development periods of the Paleocene basin are reflected in it: Danian (Early — Late), relatively long (-3,8 Ma); and Zelandian, which duration is not over ~ 1 Ma. In the Katchian regional stage (Upper Paleocene, Zelandian, Thanetian), the Lazurnoye suite up to 200 m thick is defined, which has three-component structure (fig. 3).
The Paleocene formation is characterized by a complicated spatial-temporal structure that reflects various sedimentation stages under different conditions depending on the morphology and mobility of the basin’s bottom and its elements (shelf zone, continental slope) as well as sedimentation cyclicity with sedimentation cycles of various rank of the corresponding stratons.
Ma General scale Regional stratigraphic divisions
Paleomagnetic scale Е о £ со UJ ' ■j: ф со со (Л Foraminifers (Berggen et al., 1995) Nwnoplrtofl (ІЩ1971) Biostratigraphic characteristic Regional stage (Л OJ 1 <o a> '5 <Л 0 1 </> Lithological characteristic
• І ' NN21 Emilia hyxteyi, Porosononion martkobl. Ammonia compacta Recent Dzhemetian layers > coccolith muds Up to 15 m
V і / Г* NN20 Mytilus galtoprovincialis, Abra ovata, Hydrobia vontrosa, Canalifora parkorae. Trachilyberis edwardsi Black Sea Kalamit layers > sapropelic muds Bugaz-Vitiaz > biogenic-terrigenous muds Up to 30 m
QC < ш го Globorotalia inflata. Monodacna caspia, Droissena rostriformls. Dr. polymopha. Micromollania lincta. Monodacna caspia New Euxinian Clays, sapropelic muds Up to 200 m
C1 ■:'Г. а: ш 2 г Cardium edulo, Paphla discropans, Bittum rotlculatum, [' :! -■ . і' ’ ' --- Post-Karangatian Sandy-clayey sediments Up to 30 m
О 0 L _ Gr. truncatulinoidos Cardium tuborculatum.Chlamls glabra, Paphla sonoscons, -■ ■ " ' . . Karangatian Dark green clays with shell limestone Up to 50 m
<: О 1— NN19 Oroisoona potymorpho. Cnraium odu e, Viviparvj* vivipnrua. Monodacna caspia. Droiaaeno polymopha. Oidocna pontoon «pin. Chlorve ga.lina, Corbulomyna ma afterrnnoo Euxinian-Uzunlarian Lake and liman clays, loam, dark grey clays Up to 15 m
_) GO Ш _І і» Didacna pontocaspia. O. pallasl, Monodacna subcolorata, Droissona caopla. Vivlparus viviporu* Old Euxinian Clays, sands, shell limestones Up to 15 m
1 — Tschaudia tschauda, Didacna pseudocrassa, D. baericrassa Chaudian Sands, gravel loams, limestones, shell limestones, clays Up to 50 m
Didacna guriana, Dreissena polymorpha Gurian Clays, limestones Up to 50 m
С2 UJ § сс ш 3 PL 6 PL 5 -PL 4 ■*i. :j Gr. tosaensis NN18 Ammonia beccarii, Cytherissa bogatschovi, Kuyainikian
34 С2А а. г> о 5 а! Gr. iriocenica NN16 Candona donataensis, Pachydacna kuyaclinicensis Greenish-qrev carbonate micaceous clavs. siderite
4 _= 8 а: с PL 2 Gr. margarilao — NN15— Q?
5 J СЗ «І —і а. % о 15 с І Gr. tumtia — NN14— NN13 Viviparus conconcinus, Dreissensia angusta, Porosodacna macrodon Kimmerian Up to 240 m
е NN12 NN12 - Ceratolithus acutus
6.J ’є 14
і СЗА £ Gr. extremus NN11b
7-І Elphidium ponticum, Ammonia beccarii, Pontian Light greenish-grey carbonate silty clays, grey carbonate siltstones, clayey
§ сзв Congeria novorossica. Paradacna abichi with detritus and well-preserved Congeria shells Up to 120 m
8-| С4 н*ши о: с л CO - Gr. plesioturnkJa NN11a Porosononion aff. martkobi, Quinqueloculina consobrina. Q. meotica, Cibicides borislavensis. Cibiddes sp.. Meotian Clayey-silty-siderite sequence: greenish-grey clays, grey sandy
9-| С4А хвш Ш % с: о NN10 Bulimina sp. NN10 - Discoaster neohamatus easy carbonate siltstones Up to 200 m
10—і ГТІ L! f2 N. acostaensis NN9b Quinqueloculina reussi, Q. karreri, Q. consobrina, Spiroloculina okrajantzi, Articulina problema. Dark grey carbonate and non-carbonate clays, organogenic-detrital chalk-like limestones, marls, greenish-grey clays, light grey sandstones
114 С5 M 1? Gr. menardc NN9a — NNft.— A. sarmatica, A. stelligera, Elphidium incertum, Elph. aculeatum, Porosononion martkobi, P. subgranosus, Spiroloculina kolesnikovi, Nonion bogdanowiczi, Uvigerina asperula Sarmatian
С .2 M 11 Gr. mayeri NN7 Lower part - clayey-siltstone Up to 500 m
С5А о W- NN6
8!ав С.5АС C5AD ш to LU _І > 03 M 7 Gr. fohsi lobata Gr. fohsi fohsi Ammonia pseudobeccarii, Elphidium hudakoense, Elph. macellum tumidocamerata, Elph. fichtellianum, Nonion cf.stremlus, Globigerinoides bisphaericus, Turborotalia mayeri Kon kia n Interlayering: light grey organogenic-detrital limestones,
14-f ваги О 5 о с/з NN5 Karaganian grey-green clays, grey and dark grey marls (motley, ocherous-irony), siltstones, light grey sandstones with shell detritus Up to 250 m
С5В cij — NN5 - Sphenolithus heteromorphus
16—1 CJ о СЗ _• M OD M Praeorb. glomerosa Globlgorlna tarchanensis, Bolivina tarchanensis, Sigmoilina tenuis. Quinqueloculina selene. Tarkhanian Dark greenish-grey clays, easy carbonate, layered Up to 100 m
17-= vyOvy С M 4a NN4 Saccamina zuramacensis, Neobulimina elongata, ■ — Г
18 -| C5D 03 M 3 Gr. insueta Uvigerinella californica. Nonion bogdanowiczi, Porosononion dendridicus, P. polymorphus, Hyperammina caucasica, Haplophragmoides, C/3 Interlayering: silty clays (grey, sandy, non-carbonate) and sirierite
| С5Е вв ао NN3 Bathysiphonian a>
19 —і С6 X ш $ "О U- ... Cat stainforthi Cyclammina, спікули губок, піритизовані залишки риб NN 3 - Sphenolithus belemnos o
20-І CQ M2 Б Dark grey carbonate clays Up to 500 m
21-| С6А =3 о -J I Col dissimilis NN2 L J
=3
o*
<
tu
§
CJ
O
O
CJU
U3
O
O
c
.2
*2
o
t:
CO
P22
Gl. anguSsuturah/Ch. cubcnsis CRSZ
P20
P18
Gr. kugtori
01. dperoensis PRZ
Gl. angulisuturalis • Pg. opima $. s ISZ
T. ampfiapertura IZ
T. cerroazulensis -Pseudohasbperina spp.
Subbotina
instabilis
Subbotina
aaerbaidjarica
NP 25
NP24
NP23
=T
NP 21
NP 17
NP 16
Haplophragmoides rotundidorsatus, Saccammina grzybowskii, Eponides noniformis, Uvigerinella majcopica, Heterolepa oligocenica, Caucasina schischkynskae, Bolivina goudkoffi caucaslca
Globigerina dperoensis, Spiroplectammina terecensis, Spaeroidina variabilis, Haplophragmoides deformabilis Grzybowskiella tenuis, Brizallina missisippiensis,
Gl. praebulloides_______
Cibicides borislavensis, Lenticulina obessa, Asterigerina rotula, Nodosaria consobrina, OcTpaKoflw: Pterygocythereis ceratoptera, Pontocypris oligocenica
Cyclammina conslructimargo, Spiroplectammina carinata, Cibicides amphisyliensis, Haplophragmoides fidelis, Globigerina tapuriensis, Planorbella
Solivina antegressa, B. mississippiensis, Asanospira waiter!, Glomospira charoides, Hyperammina lineariformis. Spiroplectammina costldorsata, Cibicides pseudoungerianus, Pianulina costata, Globigerapcis tropicalis,
Gf. Index._________________________________________
Subbotina turcmenica, S. frontosa,
S. instabilis, S. inflata,
Truncatulinoides rohri, Hyp. lineariformis, Reophax splendidus, Brotzenella acuta, Bolivina binaensis, Acarinina rugosoaculeata
Caucasian
Kerleutian
Molotchanian
Planorbelian
Almian
Kumian
s
Grey easy silty clays, easy carbonate.
Fine interlayering: greenish-grey silty clays, non-carbonate siltstones
Up to 250 m
Dark grey to black and greenish-grey clays, dense, non-carbonate, pyrite-enriched
Up to 100 m
Clayey-siderite sequence: interlayering clays, siderite rocks, sandstones, siltstones. Greenish-dark grey massive clays with interlayers of dense siderite rocks Up to 700 m
Dark grey, greenish clays, fine layered, with
rare siltstone interlayers Up to 300 m
Greemsh-grey clays, silty, non-carbonate, with siltstone interlayers. Greenish-grey clays, silty, easy carbonate with rare siltstone interlayers _________________________________________________________________Up to 610 m
Marls, limy clays, greenish-dark grey, with silty siderite and pyrite admixtures Up to 420 m
Interlayering marls, siltstones, and clays grey, grey-brown. Rhythmits
110-400 m
41-= ““
42-| C19r
43-| C20n m ИЯ
44_| 45-1 C20r
47-1 C21n ' . vv ’
48—| C21r
C22n
50-1 C22r ZJ
51-1 C23n
52- = C23r
53-| C23n
Я Й 8 fc 8 8 S 5 C24r C25n C25r ~ ____
C?6n C26r '-.■■7m I C27r
62- ■
63- 64 | C28n E C29n
Ш 2 Ш
w Q
o 5 C
o cd
w <L>
Her.fcwwna теюсага/
H liebusi
КслгУОпл ідшЬпааш&Мяк
Hantkenina australis
Globigerinaiheka
index
Globigerinathoka
sjbconglcbata
Oay'-gerinelajarftsif НзгЛеліа aragonersis
Acarinina ЬиЯЬпбШ1 Mofpzovoiia caueaalca оммаміоалпоКж. ШВая b/otozovoza eaucevlca/
NP14 NP 13
Globigerinateca subconglobata,
Acarinina rotundimarginata,
Heterolepa morosovae, Caucasina eocaenica Globanonalina micra, Asterigerina rogalai, Hantkenina liebusi, H. alabamensis, Caucasina eocaena, Cibicides westi, Uvigerina costellata
Acarinina bullbrooki, A. centralis,
A. pentacamerata, Morozovella aragonensis, Anomalina costiana, A. liebusi,
Epistomina paleogenica, Bolivina asiatica
Novopoavlovian
Simferopolian
Marls, biomorphic-detrital limestones, foraminiferal with interlayers of limyclayey silicites
Flinty-limy-clayey sequence
Up to 150 m
Interlayering marls and limy clays; siderite opokas, limestones
Up to 60 m
Morozovella
lensiformis
Morozovella
marginodentata
Morozovella subbotinae (s.s.)
Morozovella aequa (sJ.)
NP 12 NP 11 NP 10 NP9
Morozovella subbotinae, M. marginodentata, Subb. triloculinoides, Acarinina subsphaerica, A. pentacamerata, Subbotina nana,
S. nartanensis, Glomospira corona,
Nodellum velascoense, Recurvoides varius, Hyp. cylindrica, Karreriella aegra, спікули губок, радіолярії.
Bakchisarayian
Marls clayey, silty; silty non-carbonate clays; siltstones flinty, spongiolith, limy
Up to 150 m
Acarinina sokJa&Dersis
NP8
Acarinina subsphaerica
NP7
Acarinina acarinata, A. subsphaerica, Igorina djanensis, Anomalinoiges ferus Cibicides lectus, Carphathiella ovulum Grzybowskiella angusta
Katchian
Limy clays, marls, limestones foraminiferal, crinoidal, spongiolith-crinoidal, organogenic-detrital
Up to 200 m
ррб
Igorina djanensis
Morozovella conicotruncata
Morozovella angulata
PP3
re
Acarinina
inoonstans
йіХилопжла сотроіи
Parasubbotna
pseudobulloides
NP6 NP 5 NP4 NP1-3
Morozovella conicotruncata, M. angulata s. str., Acarinina inconstans, Globoconusa daubjergensis, Globigerina taurica, Eoglobigerina eobulloides, Anomalinoides danicus, Brotzenella praeacuta, Subbotina triangularis
Belokamenkian
til. plnnocomprein
JSrnu—
Limestones organogenic-detrital, crinoidal-spongiolith; marls; siderite rocks Up to 100 m
Interlayering; marls, flinty limestones
limy clays,
Up to 250 m
Fig. 3. Stratigraphic chart of the Cenozoic deposits of the western Black Sea basin
EOCENE. Bakhchisaraian regional stage (Lower Eocene, Ypresian). A feature of the Okunevka suite is prevailing in the section greenish-grey clay, marl and grey limestone (up to 170 m thick). The Bakhchisarain time was the beginning of new stage of the transgression sedimentation cycle, carbonate-clayey on deep water, relatively steady shelf locations of the marine basin, where geomor-phological, tectonic, and hydrological agents did not have a discrete influence over sedimentation processes. The marine transgression northward was insignificant that was evidenced by the absence or low thickness (up to 10 m) of lime-stone-spongolite sediments in boreholes on the adjacent lands near the Black Sea.
Simferopolian regional stage (Middle Eocene, Lutetian). The Simferopolian suite consists of two lithocomplexes: marl-limy-clayey (lower), siltstone-siderite-clayey. During that development stage of the Eocene basin, changes in the sedimentation conditions happened on the northwestern shelf, when sediments (spongolite, opoka) accumulated under conditions of relatively cooling water masses and transgression-regression fluctuations.
Novopavlovkian regional stage (Middle Eocene, Lutetian). The Novopavlovka suite is characterized by prevailing silica-carbonate-clayey rocks with siderite in the lower portion of the section, and limy-marl-clayey sediments in the upper one.
Kumian regional stage (Middle Eocene, Bartonian) is a peculiar thick formational complex of the upper part of the Middle Eocene that occurs in the Crimean-Caucasian region and is a rather characteristic straton within the northwestern shelf. The Kuma suite, which corresponds in its volume to the Kumian regional stage, consists of greenish-grey and grey-brown marl with interlayers of carbonate clay and siltstone. A presence of rhythmites is a feature of the Kumian regional stage. The Middle Eocene accumulation of clayey-carbonate and carbonate muds had a clear cyclic tendency, when in the end of each of time intervals mentioned above (Simferopolian, Novopavlovkian, Kumian), carbonate forming gradually increased. The recognized breaks in sedimentation reflect the critical stage in the regional development and complete the transgression-regression cycle.
Almian regional stage (Upper Eocene, Priabonian). The Alma suite is a marl-clayey formation with characteristic lamination both the rocks and bios. Their matter composition evidences that in the Late Eocene time mainly abyssal low-carbonate-clayey mud accumulation prevailed on the northwestern shelf of the Black Sea under steady hydrodynamic and mainly reduction physical-chemical conditions. Comparisons of the Alma suite of the shelf and adjacent northern coastal regions and Crimea demonstrate the different biolithofacial conditions and rather individual development history of those regions. In the same time, an analysis of the taxonomic composition of foraminifers and regularities of their distribution in the Almian section of the NW shelf demonstrates that they have many common with foraminiferal complexes from sediments of the Popele and Bystritsa suites (Ukrainian Carpathians), with which significant hydrocarbon accumulations are related.
OLIGOCENE. The stratigraphic structure of the Oligocene of the NW shelf consists of three transgression-regression cycles. Those are regional
stages in the stratigraphic scheme: Planorbelian, Molotchnaya, Kerleutian, and in part Caucasian. From biostratigraphic data, the age of the Planorbelian and Molotchnaya regional stages is Rupelian, and that of the Kerleutian is Chattian. Generally, the age range of the Maikopian rock complex covers the Rupelian-Burdigalian (the Oligocene-Lower Miocene) [20].
The Planorbelian regional stage (Lower Oligocene, Rupelian) is determined in the volume of the Planorbelia suite with two subsuites. Planorbelian sediments occur everywhere on the shelf, and we found them on the continental slope [6, 9]. On seismostratigraphic data their thickness reaches up to 1,500 m.
Molotchnaya regional stage (Lower Oligocene, Rupelian). The Molotchnaya suite is represented by interlayering clay, siltstone, sandstone, and siderite rocks.
Kerleutian regional stage (Upper Oligocene, Chattian). Two subsuites are recognized in the volume of the Kerleut suite. The lower one consists mainly of dark grey, almost black clay, the upper one is an interlayering of clay, siltstone, sandstone [11, 17].
An analysis of the biolithostratigraphic and structural-tectonic constituents shows that the Oligocene sediments of the Southern Oil-Gas-Bearing Province are in a joint zone of different paleosedimentological districts. If the NW shelf is a typical relatively marine basin of average salinity with typical biocoenotic groups of planktonic and benthic microorganisms that northward their substitution is observed with shallow-water marine brackish biocoenoses, which characterize a morphostructurally differentiated basin with different conditions of sedimentation and different history of geological development.
NEOGENE SYSTEM. MIOCENE. Proceeding from the analysis of the Neogene section of the Black Sea’s NW shelf and its correlation with sections of adjacent territories, the model of stratigraphic structure was created for the first time, and the recognized stratons of the regional stage rank is described: Caucasian and Bathysiphonian of the Lower Miocene; Tarkhanian, Chokrakian, Karaganian, Konkian of the Middle Miocene, and Sarmatian of the Middle-Upper Miocene; Meotian, Pontian, Kimmerian, Kuyalnikian of the Upper Miocene-Pliocene. The facial and spatial-temporal changes of chronostratigraphic divisions were cleared for the NW shelf and continental slope of the Western Black Sea Depression. In the supposed stratigraphic scheme for the Neogene, the Mediterranean Neogene scale was used as international, aspects for substantiation of the stratigraphic divisions were considered for the Eastern Parathetys and its constituent part — the Neogene of Southern Ukraine [1, 20, 27-31].
Caucasian regional stage (Lower Miocene, Aquitainian). We conventionally relegate the upper potion of the section of the Upper Kerleut subsuite and the lower part of the Illitchevsk suite to this regional stage. The upper part of the Upper Kerleut subsuite is clayey-siltstone thin-laminated rock complex with penurious foraminifer complex. The section is gradually substituted with dark grey clay of the Illitchevsk suite with rare benthic
foraminifers in its lower part, where sponge spicules, diatoms and piritized fish skeleton remnants prevail, which give very problematic dating of the sediments. The Caucasian regional stage on the available evidences is diachronous — Chattian-Aquitanian. Therefore, the conventionality of the Miocene-Oligocene boundary in the sections of the NW shelf clearly reflects the general discussion character of the boundary in the Eastern Parathetys [21, 28].
Bathysiphonian regional stage (Lower Miocene, Burdigalian). The Illitchevsk suite corresponds to this regional stage on the NW shelf. It is represented by interlayering greenish-grey sandy clay, non-carbonate siltstone with siderite, dark grey clay (easy carbonate and carbonate). The Bathysiphonian regional stage corresponds in Plain Crimea and coastal regions to the Sakaraulian and Katsakhurian regional stages with Arabat, Korolevo, Chernobaivka suites and Komrat and Karzhin layers. The age of the Bathysiphonian regional stage is Early Miocene.
, Tarkhanian regional stage (Middle Miocene, Langhian). Its sediments occur in sections of the almost all boreholes on the shelf and continental slope of the Black Sea. They with break cover the Maikopian sediments and are covered by carbonate-clayey Chokrakian-Karaganian-Konkian deposits. They are interlayering greenish-grey, dark grey clay, siltstone, marl. Clay sometimes contains an admixture of siltstone, easy carbonate or non-carbonate. Their visual appearance is similar to the Maikopian ones. Foraminifers and nannoplankton evidence that the Tarkhanian regional stage spans the end of the Early — Middle Eocene.
Chokrakian, Karaganian, Konkian regional stages (Middle Miocene, top of the Langhian — Serravallian) have been drilled known on numerous structures of the NW shelf and Western Black Sea Depression. Due to limited volumes of core samples, it is today impossible to recognize each of these regional stages on the shelf through their biological, lithological and geophysical features. Therefore, a non-divided clay-limestone sequence is shown in the scheme (Fig. 3), which are clearly traced as an uniform formational complex. On the shelf, Marginal Escarpment, continental slope of the Western Black Sea Depression, the Chokrakian-Karaganian-Konkian sequence consists of grey, light, cavernous limestones with shell detritus, interlayers of siltstone and massive dark grey marl. The thickness of the sequence is up to 250 m. The age of the Chokrakian, Karaganian, Konkian sediments is Middle Miocene.
Sarmatian regional stage (Middle-Upper Miocene, Upper Serravallian
— Lower Tortonian) is penetrated almost in all boreholes on the NW shelf and dragged on the continental slope of the Black Sea.
Geophysical data enable to recognize three lithostratons almost on all uplifts. The lower one is dark-colored clay-siltstone with rare limestone and sandstone interlayers. The middle lithostraton is limestone-clay with significantly increased content of organogenic-detritic limestone, with characteristic greenish-grey color of clay. The upper lithostraton is clayey
— interlayering of dark grey carbonate clay, marl with and without
carbonates, siltstone and limestone. The thickness of the Sarmatian sediments ranges between 50 and 560 m.
Different notions exist about age of the Sarmatian regional stage. If the majority of geologists accepts the Late Miocene that the newest examination suppose to date the Sarmatian as the end of Middle Miocene (Serravallian) — Late Miocene (Tortonian) that embraces the interval of 9,612,8 Ma [13]. I.e., the duration of the Sarmatian is 3,2 Ma.
The Meotian regional stage (Upper Miocene, Tortonian) has been drilled in fact on all uplifts of the NW shelf. Its section consists of interlayering limestone, clay, 20-400 m thick. The Meotian sediments cover with break the Miocene, Oligocene rocks and occur beneath the Pliocene-Quaternary ones. From plankton foraminifers and nannoplankton [8] the Lower Miocene (Tortonian) age is justified for the Meotian formations of the NW shelf and continental slope, which accumulated during 1,9 Ma.
Pontian regional stage (Upper Miocene, Messinian). The Pontianr Messinian sequence is present in almost all sections of the NW shelf. But its stratification, in part concise recognition of the Pontian sediments, is complicated due to the practical absence of core samples and standard logging data. The thickness analysis shows that the upper portion of the section is represented (in sludge) by greenish-grey carbonate clay, siltstone grey, carbonate, clayey with detritus and whole mollusk shell of 40-60 m thick.
The limestone-marl Pontian sediments up to 10 m thick have been found on the NW shelf in the Bug, Dnieper, Dniester Limans, on the Odessa Bank by ship drilling; we also have traced them on the continental slope [5, 15, 39].
Comprehensive studies by V.N. Semenenko and co-authors [22] determined the position of the Pontian of the Eastern Parathetys in magnetochronological scale. It correlated with Mediterranean stages. Accordingly these data, the Pontian regional stage was the upper division of the Miocene correlating with upper portion of the Tortonian — Messinian, its age 7,5-6,5 Ma.
PLIOCENE. Kimmerian, Kuyalnikian regional stages (Upper Miocene-Pleistocene, Messinian-Helazian). Though almost all boreholes on the NW shelf gives geophysical data on the presence of the Kimmerian-Kuyalnikian sediments, the available evidences do not enable detailed stratification of the sequence. The thickness of the sequence varies. So, it is 95 m in b/h 01impiyska-400, up to 60 m on the Shmidt Uplift, 30-40 m on the Stormove Uplift. On the shelf this part of the section in numerous boreholes consists of greenish-grey, carbonate clay, siderite sandstone with ostracodes and rare foraminifer and mollusk shells. On the continental slope it is dark, almost black clay. In the Karkinita Trough the Pliocene age of Kimmerian-Kuyalnikian sediments is determined by foraminifers, nannoplankton and mollusks [5].
QUATERNARY SYSTEM. PLEISTOCENE-HOLOCENE. The Pleistocene and Holocerie sediments on the NW shelf and continental slope of the Black Sea are stratified applying the event principle [8, 9, 16, 34-38].
The determined regional stratons correspond to certain stages of climatic-eustatic events and cover transgression-regression cycles in the whole. This complex of terrigenous laminated rocks has a monocline dipping towards the Black Sea Depression. Sediments of the shelf, continental slope and abyssal depression are clearly recognized. Intraformational discontinuities and breaks are observed in them as well as a significant proportion of alluvial and continental deposits. Unlike the adjacent coastal territories, where numerous local horizons are recognized, the stratigraphic division of the Quaternary sediments is carried out of the regional level (regional stage). The Gurian, Chaudian, Old Euxinian, Euxinian-Uzunlarian, Karangatian, Post-Karangatian, New Euxinian, Black Sea regional stages are recognized in the Pleistocene-Holocene. Each of these stages has transgression-regression cycles, which relations in the section reflect the corresponding epochs of the basin development.
The Kimmerian sediments consist of non-carbonaceous clayey muds— dark green-grey, olive with interlayers of diatomic and siderite mud. The Kuyalnik section is also non-carbonaceous siltstone, silty and diatomic clay enriched with amorphous silica. The Chaudian sediments contain cyclites with interlayers of carbonate muds in the bottom.
The inherited nature of cyclic sedimentation is observed in the Old Euxinian, when clayey with sand lens and interlayers of turbidites, thin-layered high-carbonaceous coccolith and clayey-sapropelic muds. Clay and silty clay dominate in the Karangatian; they are enriched with organic matter, with gradation texture that is a feature of the top of the Karangatian section. Non-carbonate or easy carbonate muds with highly carbonaceous interlayers are characteristic of the transgressive New Euxinian cycle.
The Black Sea sediments are represented by thin interlayering of terrigenous non-carbonate, easy carbonate, pelitic and aleuropelitic muds with poor organic matter; sapropel-like, sapropelic-clayey and sapropelic muds, high-carbonate, microlayered nannofossil muds with high organic content. This cycle clearly demonstrates a climatic influence. Since the Late Pliocene, the well-known period of alternating glacial and interglacial conditions begins, and the shelf either uplifts over the sea level at large areas or covers with sea water. Such climatic cyclicity is clearly evident in the matter composition and structure of the rocks. Dominating sediments of the Quaternary section accumulated in transgressive (Chaudian, Karangatian, New Euxinian) and regressive (Post-Chaudian, Post-Karangatian, Early Euxinian) phases. The inherited development of main structural-geomorphologic elements and sedimentation cyclicity are clearly observed.
A significant part of the Pliocene-Pleistocene complex of the NW part of the Black Sea consists of an abyssal fan. Seismics and evidences of d/v “Glomar Challenger” have identified older (Lower Pleistocene and Post-Miocene) fans of Danube and Dnieper. We have identified fan sediments in the Paleocene-Eocene sediments of the Karkinita Trough and Marginal Escarpment. Therefore, the Cenozoic development of the fans was periodical and inherited. The same periodicity is observed also in the influence of
gravitational flows and slides on the shelf and its marginal part over sedimentation process, and on the continental slope turbidite flows too.
In general, the Pleistocene-Holocene history of the shelf has signs of the marine basin cyclic development that repeats with various time intervals, changes in the sea level due to periodical connections with the Mediterranean, climatic and tectonic factors. The hydrological factor is also of big importance depending on sea level fluctuations and river drainage.
The Pliocene-Quaternary stage, especially recent sedimentation, has factors of the sedimentation environment and types of sedimentation complexes similar to the Paleogene and Neogene ones. The inherited nature of cyclic marine sedimentogenesis is traced through the Cenozoic. In the facial structure of the Black Sea horizon we see recent analogs of the systems, which have features of former environments, e.g., potentially petroleum-producing formations (sapropelic, carbonate-terrigenous formations).
Recent sedomentogenesis on the shelf and continental slope of the Black Sea is an active analog of the Paleogene and Neogene facial systems, in part the Oligocene domanik complex that can be a model for reconstruction of Cenozoic sedimentogenesis.
On the continental slope adjacent to the northwestern shelf in the aquatory of the Crimean Megaanticlinorium, the age of rocks has been determined that proves identity of the stratigraphic Mesozoic-Cenozoic sequence (fig. 1). Sedimentary rocks are represented by the Upper Triassic, Jurassic, Cretaceous, Paleogene, Neogene and Quaternary rocks. The Paleocene, Eocene, Oligocene and Miocene deposits were identified at the southern continental slope of Crimea. The Oligocene and Early Miocene sediments are transgressively overlying Cretaceous and Paleocene-Eocene sediments of the Foros area. The younger Miocene and Quaternary rocks are also transgressively overlying the Jurassic deposits of the Yalta-Gurzuf and Alushta Blocks. These data enable us to give a new interpretation of the structure of the western and central blocks of the Crimean continental slope. Earlier, this part of the slope was considered to be the marginal part of the Crimean Megaanticlinorium, but new biostratigraphic data make it possible to consider that this part can be a jointing zone of peripheral structures of the Black Sea Basin and Crimean Megaanticlinorium, and identified Paleogene deposits, in particular, are the structures of the north slope of the West Black Sea basin.
Forming of a continental slope is the process that does not occur at the same time, to which testifies lithological and microfaunal composition of rocks. In the Triassic and Jurassic on the continental slope deposition of sediments occurred, which formed small rhythmic flysch deposits of considerable thickness and volcanogenic terrigenous complex. The Cretaceous phase is characterized by the development of carbonate tufa rocks and limestones containing biogenic silica. Volcanic activity is characteristic of this period. The beginning of the Paleogene in the Black Sea Region is characterized by the changing sedimentation regime and decreasing tectonic activity. There were a general increase in the depth of sedimentation, as the systematic composition of plank-
tonic and benthos foraminifers from the drilled rocks testifies. We should notice that composition of rocks and association of foraminifers, contained in them, is similar to the Paleocene, Oligocene bio- and lithofacies of the Kertch Peninsula, Black Sea northwestern shelf, and Carpathians. The latitudinal correlation by such factors as type of sediments, composition of litho- and biofacies and thickness testifies to the presence of genetic connection of the Paleogene deposits of Crimea (Kertch and Tarkhankut Peninsulas), the northwestern shelf, continental slope of the Black Sea and Carpathians. Very likely, it was the only sufficiently deep structural-geomorphologic segment of the Tethys basin that stretched from the Caucasus through the Black Sea Depression, Romania and Carpathians.
In the south part, in the boundaries of the economic zone of Turkey, the Black Sea continental slope is composed, according to obtained bio- and lithostratigraphic data, of the Upper Cretaceous (Turonian, Maastrichtian), Paleogene (Lower-Middle Eocene) and Miocene (Middle Miocene and Sarmatian) deposits. The subflysch Cretaceous and Paleogene deposits have many common features and are similar to the rocks of the northwestern shelf and continental slope of the Black Sea’s northern part. In the south part of continental slope, as early as in the Mesozoic, existed deep sea basin. There is an observed inheritance of deep-sea sedimentation in the Eocene and partly in the Miocene. That is to say, in the south segment of the Black Sea basin, which stretches from Adjaro-Triolettia through Pont to the Balkan Mountains, there existed, during the definite geologic intervals, sedimentation conditions similar to those of the north segment.
1. Barg I.M. Biostratigraphy of the Upper Cenozoic . — Dniepropetrovsk, 1993. — 196 p.
2. Catuneanu O. Geology of the Black Sea Romanian Shelf of North-Dobrugean type // Useful resources Revue Roumaine de Geologie. — Bucuresti, 1994. — Vol. 38. — P. 53-65.
3. Emelyanov E.M., Shimkus K.M. To the issue of investigation of deep sea sediments of the Black Sea // Oceanology. — 1962. — Vol. 2, № 6. — P. 1040-1049.
4. Geology of USSR shelf. Lithology. — Kiev: Nauk. Dumka, 1985. — 189 p.
5. Geology of USSR shelf. Stratigraphy. — Kiev: Nauk. Dumka, 1984. — 184 p.
6. Geology of USSR shelf. Tectonics. — Kiev: Nauk. Dumka, 1987. — 150 p.
7. Gordiyevitch VA., Bondarenko V.G., Plotnikova L.F., Nazarov N.V. New data on geology of the Black Sea shelf by drilling results for the Illitchivsk structure // Tect. & Strat. — 1984. — Is. 25. — P. 60-65.
8. Gozhik P.F., Maslun N.V., Baiysarovish I.M. Geological model of Laspian canyon of Crimean continental slope // Dokl. AN USSR. Issue B. — 1990. — № 7. — P. 88-97.
9. Gozhik P.F., Maslun N.V., Ivanik O.M. Features of the stratigraphic structure of the Anthropogenous sediments at the Black Sea’s northwestern shelf // Tectonics and stratigraphy. — 2005. — Is. 34. — P. 103-115.
10. Gozhik P.F., Maslun N.V., Plotnikova L.F., et al. Mesocenozoic stratigraphy of the the Black Sea’s northwestern shelf. — Kiev, 2006. — 171 p.
11. Gozhik P.F., Mitropolsky O.Yu., Maslun N.V., Tsychotska N.N. Lithofacial model of Neozoic sediments as a background for studying processes of lithogenesis and oil and gas accumulation factors of the Black Sea Basin // Tectonic and accumulation of oil and gas on continental shelf: Proceedings of International Conference. — 2000. — P. 45-47.
12. Gozhik P.F., Mitropolsky O.Yu., Maslun N.V., Tsychotska N.N. Peculiarities of sedimentogenesis in the Black Sea Depression in the Neozoic period // Geology and mineral resources of the Black Sea. — Kiev, 1999. — P. 210-214.
13. Handenbol J., Thierry J., Farley M. et al. Cretaceous biochronostratigraphy // Mesozoic and Cenozoic Sequence Stratigraphy of European Basins (En De Gracianski, P.-C., Handenbol, J., Jacquin at al.) / SEPM Spec. Publ. 60. — Oklahoma, 1998. — 786 p.
14. International Stratigraphic Guide / Ed. Hedberg H.D. — New York: John Wiley and Sons Inc, 1976. — 200 p.
15. Ivannikov A.V., Inozemtsev Y.Y, Maslakov NA., Maslun N.V., Pyatkova D.M., Stupina L.V. Stratigraphic research of Black Sea continental slope and shelf // Geology and mineral resources of the Black Sea. — Kiev, 1999. — P. 245-254.
16. Maslun N.V., Inozemtsev Yu.I., Orovetsky Yu.Yu. The Lower Cenozoic sediments of the Crimean continental slope, Black Sea. — Kiev, 1989. — 35 p. — (Prepr. / IGN NASU; 89-13).
17. Maslun N.V., Ivanik MM., ShumnikAV., Tsykhotska NJS!., Kliushina G.V. Biolithos-tratigraphic structure of the Olimpiyske Uplift — a constituent of the geological model of the Marginal Escarpment of the Black Sea northwestern shelf // Paleontological investigations in Ukraine: history, recent state and outlooks. — K.: IGN NASU. — 2007. — P. 206-211.
18. Maslun N.V., Tsychotskaya N.N. Sedimentation cyclicity of the Paleocene deposits of northwestern shelf of the Black Sea // Geol. Journ. — 2001. — № 1-2. — P. 125-129.
19. Moroz SA., Sulimov I.N., Gozhik P.F. Geological structure of the Northern Black Sea. — Kiev: Nauk. dumka, 1995. — 184 p.
20. Nosovsky M.F. Regional stratigraphic scale for the Maikopian sediments of Plain Crimea // Geol. Journ. — 2003. — № 3. — P. 137-145.
21. Nosovsky M.F. Upper Oligocene of Southern Ukraine // Bull. Mosc. Natur. Soc. Dept. Geol. — 2003. — Vol. 78, is. 1. — P. 49-53.
22. Pevzner MA., Semenenko V.N. Vangengeym EA. Position of the Pontian of the Eastern Parathetys in the magnetochronological scale // Stratigrraphy. Geol. Correlation.
— 2003. — Vol. 11. — № 5. — P. 72-81.
23. Plotnikova L.F., Maslun N.V., Ivanik M.M., Tsychotska N.N., Shumnik A.V. Cretaceous-Paleocene stratigraphy and geological development peculaties of western part of northwestern Black Sea shelf // Geol. Journ. — 2003. — № 2. — P. 27-38.
24. Plotnikova LJ"., Yakushin LM., Ishchenko I J. Detailed stratification of the Lower Cretaceous sediments of the northwestern Black Sea shelf // Biostratigraphic criteria for division and correlation of the Phanerozoic sediments of Ukraine. — Kiev, 2005. — P. 75-79.
25. Plotnikova L.F., Yakushin LM., Ishchenko I.I. New data on stratigraphy of the Cenomanian deposits of the northwestern Black Sea shelf // Modern directions of the recent Ukrainian geological science — K.: IGS NASU, 2006. — P. 249-254.
26. Samsonov V.I., Lytskiv S.S., Chepijko A.V. Peculiarities of the geodynamics of the South-East region of Ukraine related to the perspective of oil and gas contamination // Resources of Crimea and bordering waters (oil and gas). — Simferopol: Tavriya-Plus, 2001. — P. 131-137.
27. Semenenko V.N. Neogene terraces of the Black Sea coast and continental slope // Geological problems of the Black Sea. — Kiev, 2001. — P. 245-252.
28. Semenenko V.N. Stratigraphic correlation between Upper Miocene and Pliocene of the Eastern Parathetys and Thetys. — Kiev: Nauk. Dumka, 1987. — 230 p.
29. Semenenko V.N. Stratigraphic correlation between Upper Miocene and Pliocene of the Eastern Thetys and Parathetys and Thetys. — Kiev: Nauk. Dumka, 1987. — 230 p.
30. Semenenko V.N. The Upper Miocene molasses of the Alma Trough // Geol. Journ.
— 2003. — № 2. — P. 39-57.
31. Semenenko V.N. Marine Quaternary dements of the Azov — Black Sea Basin // Main results in Quaternary studies and principal investigation directions in XXI Cnt. — SntPtb.: VSEGEI, 1998. — P. 208.
32. Shnyukov J.F, Grigoriev A.V. Maslun N.V., Sobolevskiy Y.S. Desbastilar M.K., Pyatkova D.M., Orovetsky Y.Y. Mesozoic and Neozoic sediments of Southern continental slope of the South Sea // Geol. Journ. — 1991. — № 2. — P. 123-129.
33. Shnyukov E.F, Lutsiv Ya.K., Inozemtsev Yu.I. Geological structure of the Quaternary sediments in the Odessa-Dniester Region of the Black Sea // Study of the geological history and recent sedimentary processes in the Black and Baltic Seas. — Kiev: Nauk. dumka, 1984. — Pt. 2. — P. 54-60.
34. Shnyukov E.F. et al. Geological studies in 44 trip of SV “Academician Vernadsky” in the Black Sea. — Kiev, 1993. — 75 p.
35. Shnyukov E.F. et al. Stratigraphic, lithological-petrographic and hydrochemical studies in 51 trip of SV “Mikhail Lomonosov” in the Black Sea. — K., 1990. — 51 p. — (Prepr. / IGS NASU; 90-9).
36. Shnyukov E.F., Dovgy SA., Starostenko V.I., Gozhik P.F. et al. Geological evaluation of the submarine cable trace Sevastopol-Zatoka. — Kiev, 2002. — 120 p.
37. Shnyukov E.F., Maslun N.V., Inozemtsev Yu.I., Orovetsky Yu.Yu. New data on the geological structure of the continental slope in Southern Crimea // Geol. Journ. — 1990. — № 3. — P. 88-98.
38. Shnyukov E.F., Shcherbakov I.B., Shnyukova E.E. Paleoisland arch of the Northern Black Sea. — K.: DMG NASU, 1997. — 288 p.
39. Shnyukov J.F, Maslun N.V., Inozemtsev Y.Y, Orovetsky Y.Y. New data on geological structure of the continental slope of Southern Crimea // Geol. Journ. — 1990. — № 3.
— P. 88-98.
40. Stratigraphic Codex of Ukraine. — Kiev, 1997. — 39 p.
41. Stratigraphic scheme of the Phanerozoic formations of Ukraine for geological maps of new generation. Graphic attachments. — Kiev, 1993.
42. Tugolesov DA, Gorshkov A.S., Meysner L.B. et al. Tectonics of the Mesozoic sediments of the Black Sea. М.: Nedra, 1985. — 150 p.
По комплексу методов — биостратиграфическому, литологическому, геофизическому, сейсмостратиграфическому, переинтерпретации имеющихся материалов выполнена детальная стратификация отложений мезозоя и кайнозоя северо-западного шельфа и Западно-черноморской впадины. Созданы схемы стратиграфии мезозойских и кайнозойських отложений. Особое внимание уделено детализации разрезов и особенностям пространственно-временного строения продуктивных мезокайно-зойских породных комплексов. Выделены разноранговые стратоны — региояруса, свиты, пачки, слои. Проанализировано их соотношение с подразделениями Международной стратиграфической шкалы. Корреляция мезокайнозойских отложений северо-западной части Черного моря со структурами Крымско-Кавказской области позволила установить подобие и различие в особенностях их строения.
На підґрунті біостратиграфічного, літологічного, геофізичного, сейсмостратиг-рафічного методів, переінтерпретації наявних матеріалів виконано детальну стратифікацію відкладів мезозою та кайнозою північно-західного шельфу і Західно-Чорноморської западини. Створено схеми стратиграфії мезозойських та кайнозойських відкладів. Особливу увагу приділено деталізації розрізів та особливостям просторово-часової будови продуктивних мезокайнозойських породних комплексів. Виділено різнорангОві стратони — регіояруси, світи, пачки, верстви. Показано їх співвідношення з Міжнародною стратиграфічною шкалою. За кореляцією мезокайнозойських відкладів північно-західного шельфу Чорного моря та структур Кримсько-Кавказької області встановлено їх подібність Та відмінності.
