ОСАДОВІ УТВОРЕННЯ УКРАЇНИ: ОСОБЛИВОСТІ РЕЧОВИННОГО СКЛАДУ, МОДЕЛІ ОСАДКОНАКОПИЧЕННЯ ТА ЛІТОГЕНЕЗУ / Sedimentary formations of : peculiarities of composition, sedimentation models and lithogenesis

УДК 551.762.3:56.074.6:551.8(477.8)

N.M. Zhabina Sedimentary model of the Upper Jurassic – Lower Cretaceous carbonate complex in the Ukrainian Precarpathians

Жабіна Н.М. Седиментаційна модель карбонатного комплексу верхньої юри – нижньої крейди в Українському Передкарпатті

In the Ukrainian Precarpathians the Oxfordian – Valanginian deposits compose a common carbonate complex. Seven types of sections are determined in its composition: fore-reef, reef, back-reef, transitional, lagoon, shallow-water, outlying. The conditions of their sedimen- tation are characterized. The main stages of these deposits sedimentation related with eustatic fluctuations are determined: Oxfordian, Oxfordian – Kimmeridgian boundary, Early Kimmeridgian, Late Kimmeridgian – Early Tithonian, Late Tithonian – Early Berriassian, Early and Late Berriassian boundary, Late Berriassian – Valanginian. The sedimentary model of these deposits has been carried out. Keywords: sedimentary model, types of sections, facies, Upper Jurassic, Lower Cretaceous, Ukrainian Precarpathians.

В Українському Передкарпатті відклади оксфорду – валанжину складають єдиний карбонатний комплекс. В його складі виді- лено сім типів розрізу: передрифовий, рифовий, зарифовий, перехідний, лагунний, периферійний. Охарактеризовані умови їх формування. Визначено головні стадії седиментації цих відкладів, що пов’язані з евстатичними змінами: оксфорд, межа ок- сфорду і кімериджу, ранній кімеридж, пізній кімеридж – ранній титон, пізній титон – ранній беріас, межа раннього і пізнього беріасу, пізній беріас – валанжин. Створена седиментаційна модель цих відкладів. Ключові слова: седиментаційна модель, типи розрізів, фації, верхня юра, нижня крейда, Українське Передкарпаття.

INTRODUCTION World ocean eustatic fluctuations. Changes of the In the Ukrainian Precarpathians the Oxfordian – Val- sedimentation conditions in accordance with the eu- anginian carbonate complex of the genetically relat- static fluctuations caused forming the different types ed rocks extends as submeridional stripe to above of sections and complicated structure of the whole 100 km width along the depression area. This complex in the vertical and lateral directions. This complex is represented by the deposits­ of carbon- sedimentary model is shown in the picture (fig. 1). ate shelf from more deep-water in the west till the shallow-water in the east. There are the Oxfordian MATERIALS AND METHODS – Lower Berriassian reefogenic facies and Upper In the Ukrainian Precarpathians the Upper Jurassic – Berriassian – Valanginian open shelf deposits. In Lower Cretaceous carbonate complex outcrops in the accordance with the stratigraphic scheme (Zhabi- river Dnister basin and was opened by wells in the Car- na, Anikeyeva, 2007), these facies are represented pathian Foredeep and adjacent part of the East-Euro- by suites: fore-reef ones – Boniv (Oxfordian), Mo- pean platform. We have conducted a complex study of ranci (Kimmeridgian), Karolina (Tithonian – Lower materials of 240 wells and natural sections of these Valanginian); reef facies – Rudki suite (Oxfordian) deposits having used lithology-sedimentological, bio- and Opary (Kimmeridgian lower subsuite and Titho- and sequens-stratigraphical analysis and having ta­ nian – Lower Berriasian upper subsuite), back-reef ken into an account the results of petrographic, pale- facies – Gorodok suite (Oxfordian), Pidluby (Lower ontological and geophysical studies fulfilled by other Kimmeridgian), Nyzhniv (Upper Kimmeridgian – experts (Dulub at al., 1986, 2003, and other). Lower Tithonian), Bukivna (Upper Tithonian – Lower Berriasian), evaporite lagoon facies – Rava-Russka DISCUSSION AND RESULTS suite (Lower Kimmeridgian), shallow-sea deposits The Upper Jurassic – Lower Cretaceous deposits in Stavchany suite (Upper Berriassian – Valanginian). the region studied were formed in the North Tethys This complex is considerably eroded, it lies on the paleobasin. The main factor of this carbonate com- Paleozoic fundament and in the north - west of plex forming was reef-building processes taken place depression on the Middle Jurassic deposits, over- during Late Jurassic and Early Berriasian. There are lapped by the Aptian–Albian, Upper Cretaceous or determined seven types of sections formed in the dif- Miocene deposits. ferent zones of the paleobasin (fig. 2). They are cha­ The sedimentation of these deposits took place racterized by the specific lithological and paleontologi- in northern periphery of Tethys by the influence of the cal composition as a result of different sedimentation

© N.M. Zhabina, 2014

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Fig 1. Sedimentary model of the Upper Jurassic – Lower Cretaceous carbonate complex in the Ukrainian Precarpathians. 1 – 3 – Carpathian overthrusts; 4 – regional faults (Kr – Krakowets, Gr – Gorodok, SV – Sudova Vyshnya, Kl – Kalush, Nd – Nad- virna, Ks – Kosiv); 5 – drilling areas; 6 – wells, 7 – eastern boundary of Upper Jurassic sediments; 8 – 14 – types of section: 8 – fore-reef, 9 – reef, 10 – back-reef, 11 –transitional, 12 – lagoon, 13 – shallow-water, 14 – outlying. The Krakowets Fault is the western boundary of Upper Jurassic sediments. conditions and their changes in time. Fore-reef, reef tonic biota witness about that. Appearance of the and transitional types of section were opened by drill- planctonic foraminifers and tintinnids in Early Ox- ing only in the north - west of the Carpathian Fore- fordian were related to rising sea-level. At the Ox- deep. In the south-east they are overlapped by the fordian – Kimmeridgian boundary, at the end of Carpathians overtrusts. Early Tithonian and Late Tithonian, during Early I type of section (fore-reef) was opened by drill- Valanginian tintinnids associations were poor in ing in Karolina, Niklovichi, Volosha, Oselia, Grushiv, abundance and diversity because of the regressive Orchovichi, Rosiv, Morantci and other areas. These events. New genera of tintinnids appeared at Late deposits were formed in fore-reef zone in the west Kimmeridgian, Late Tithonian, during Berriassian of the reef belt. This section is composed of the correlating with the sea-level rise. Numerous ves- suites: Boniv (to 280 m thick), Morantci (to 300 m), tiges of siliceous sponges in the Lower Oxfordian Karolina (to 500 m). It is represented by the lime- microfacies and bentic foraminifers dominating in stones (micritic, oncoidal, bioclastic, and brec- associations with plantonic microfauna in higher ciated) interbedded with mudstones, siltstones, beds were related to sedimentation in the upper gravellites and breccias. These rocks often contain zone of open shelf on 50-100 m depth (maximum materials of the destruction of reef. Layers of the in Early Oxfordian). Extention of the fore-reef sec- silicified limestones were formed in transgressive tion to the east for 12 km in Oxfordian and for 5 km stages, the sandstones and shallow-water lime- during Kimmeridgian and Tithonian was a result of stones reflect the regressive events. This section the largest amplitude of sea-rise at Late Jurassic lies on the Middle Jurassic Javorov suite and over- beginning and result of the global regressive back- laped by the Miocene deposits. Thickness of fore- ground after that (Zhabina, Anikeyeva, 2003). reef section is to 1130 m, decreasing in some lots. II type of section (reef) was opened by drilling Sedimentation of these deposits took place in in Kochanivka, North Medenichi, Grushiv, Podiltci pelagic environments. Numerous vestiges of planc- and other areas. In the central part the section is

COLLECTION OF SCIENTIFIC WORKS OF THE IGS NAS OF UKRAINE, VOL. 7, 2014, 76-82 77 N.M. Zhabina - gr – Lower – Lower – Upper subsuite of Karolina suite (Upper Ber kr II – Bukivna (Upper Tithonian – Lower Berriasian), rr I – Bukivna Tithonian (Upper – Lower bk – Upper of subsuite Opary (Tithonian suite Berriasian); – Lower op II – shallow-water, 7 – outlying. 6 – shallow-water, 5 – lagoon, – Nyzhniv (Upper Kimmeridgian – Lower Tithonian), – Nyzhniv Kimmeridgian (Upper – Lower nz – Lower subsuite of subsuite – OparyLower (Kimmeridgian); suite 4 – transitional, kr I – subsuite Lower of Karolina suite (Tithonian – Berriasian); Lower op I – back-reef, 3 – back-reef, 2 – reef, Moranci (Kimmeridgian); Pidluby (Lower Kimmeridgian); (Lower Pidluby – Rudki suite (Oxfordian); – (Oxfordian); suite Rudki mr – rd rd pd – – fore-reef, 1 – fore-reef, Distribution of the Upper Jurassic – Lower Cretaceous types of section in the Ukrainian Precarpathians. Cretaceous Jurassic – Lower Distribution of the Upper bn – Boniv (Oxfordian),

– types of section: riassian – Lower Valanginian); riassian Valanginian); – Lower Stavchany suite (Upper Berriassian – Valanginian). (Upper suite – Stavchany Kimmeridgian); st (Lower suite of Rava-Russka subsuite Kimmeridgian), rr II – Upper (Lower suite of Rava-Russka subsuite Suites: Suites: Gorodok suite (Oxfordian), (Oxfordian), suite – Gorodok Fig. 2. 1 – 7

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composed of the Oxfordian bioherms (Rudki suite) Pidluby, Nemyriv, , North Medenichi and other and Kimmeridgian – Early Berriasian barrier reef areas. This section is determined at the place of (Opary suite). Oxfordian and Kimmeridgian reef de- substitute of the Oxfordian reef and back-reef fa- posits are replaced by the fore-reef Boniv and Mo- cies and the Lower Kimmeridgian back-reef and rantci suites in the western part of this type of sec- lagoon facies. These deposits are overlapped by tion (South Kochanivka, Bortiatin and other areas) the back-reef Nizhniv and Bukivna suites with the and by back-reef Gorodok and Pidluby suites in the Stavchany suite in the top. Two last of these suits east (Gayi and Stryi areas). Opary barrier reef was were eroded in some places. Oxfordian deposits formed on the more deep-water basis in the west (to 100 m thick) are composed of bioclastic and and on the more shallow-water basis in the east oncolitic limestones with interlayers of biogermic (Anikeyeva, 2005). In the top of this section reef de- (sponge) and silicified limestones. Lower Kimmer- posits locally are overlapped by shallow-sea Stav­chany idgian deposits (to 200 m thick) are represented suite. Oxfordian biogermes were separate buildups at the bottom by lower subsuite of Rava-Russka (to 150 m thick), which built by sponges at the bot- suite. There are mottled calcareous-terrigenous tom and by corals and algae above. At the top they rocks with anhydrites and gypsum. These deposits­ are overlapped by the oncolitic limestones. Depos- are overlapped by Pidluby suite – shallow-water its between biohermes are composed of bioclastic, limestones (bioclastic, biomicritic, oncoidal) and biomicritic, sandy and brecciated limestones inter- dolomites with the strata and fragments of sponge bedded with siltstones and breccias. Kimmeridgian limestones. Nizhniv suite (60–150 m thick) is rep- reef deposits (to 450 m thick) are composed of the resented at the bottom by the horizon of breccias biomicritic and bioclastic limestones (algal-sponge, with fragments of limestones and siltstones. It is foraminifera-algal with corals and bryozoans) with overlapped by oncolitic and dolomitic limestones interlayers of silicified limestones and gravellites. At interbedded with dolomites. Bukivna suite is com- different levels of the Kimmeridgian section there posed of bioclastic limestones with macrofauna are separate algal-sponge bioherms (10–70 m and algae vestiges at the bottom (20–70 m), on- thick). Tithonian – Early Berriasian reef deposits colitic limestones lie above of that, at the top with (to 800 m thick) are composed of bioclastic and the beds of sandy limestones (13 m). Stavchany biogermic limestones (created by corals, sponges, suite is composed of three packs: lower (Upper Ber- algae, bryozoans, stromatopores). Reef section lies riasian) – mudstones, siltstones and bioclastic lime- on the Middle Jurassic Javorov suite and is over- stones (to 17 m thick); middle (Lower Valanginian) lapped by the Miocene deposits. Thickness of this – bioclastic and oncoidal limestones interbedded section is about 1370 m. with clays (to 60 m thick), upper (Upper Valangin- Reef belt was formed parallelly to the coast- ian) – sandy limestones and marls with glauconite line in the lower sublittoral. In accordance with the (to 70 m thick). The transitional section lies on the reef builders paleoecology (Anikeyeva, 2002) reef- Paleozoic deposits, on the Middle Jurassic Javorov building processes took place in Oxfordian at first suite in the north-west and is overlaped by the Up- on the 100 m deep (siliceous sponge witness about per Cretaceous rocks, in places by Aptian – Albian. that), after that the deeps of the sedimentation Thickness of this section is up to 600 m. were decreased (calcareous sponge, algae, corals These deposits are characterized by vertical at Late Oxfordian). At the end of Oxfordian building replacing the Oxfordian relatively deep-water for- biogermes was stopped what was related to large mations by the Lower Kimmeridgian shallow-water regression (oncolitic limestones lie in the top of bio- ones. Oxfordian deposits were formed on depth of hermes). Reef buildups were formed on the sloping 100 m (the beds with sponge and silicified lime- shelf to 20-40 m deep during Kimmeridgian (cal- stones show that). Lower Kimmeridgian lagoon careous sponges, algae, corals) and on the sublito- and back-reef deposits were formed on depth to ral to 25- 30 m during Tithonian – Early Berriasian first tens meters (contain numerous vestiges of (corals, sponges, bryozoans, stromatopores). Du­ reef-loving bentic fauna and fragments of reef- ring Kimmeridgian – Early Berriasian reef section builders). During Late Berriasian and Valanginian was considerably moved to the west because of the the sedimentation took place on the open sublitto- influence of the global regression ral to 50 m deep (Stavchany suite contain numer- III type of section (transitional) extends in the ous shallow-water fauna, but reef-loving species is east of the Opare reef, it was opened by drilling in not multiplicity).

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IV type of section (back-reef) extends to the this area. That can be related with falling rocks of So- east of Opary reef all over the periphery the dispo- kal suite off the coast of Oxfordian sea. Rava-Russka sition of the carbonate complex. Oxfordian deposits suite lies above and is overlapped by Nizhniv suite. were opened by wells only in the north of Carpathi- Nizhniv suite is eroded in Rava-Russka area and is an Foredeep. Back-reef formations are represented absent in area. by shallow-water limestones (oncoidal, bioclastic, V type of section (lagoon) extends as submeri­ biogermic, biomicritic, micritic) and dolomites with dional stripe to 40 km width along a whole shallow- the beds of mudstones and sandstones, near the water zone of the Late Jurassic paleobasin and was coast by bioclastic limestones, carbonate clays, opened by drilling in Storozhinets, Solonets, Kras- lito-bioclastic sandstones and conglomerates. La- noilsk, Gilche, Segii, Migovo, Petrovets, Lopushna, goon was isolated in the back-reef zone of basin at Kamjanka, Kovalivka-Chereshenka, Bogorodchany- Oxfordian – Kimmeridgian boundary as a result of Paryshe, Bogorodchany, Korshiv-Ispas, Verbish, global regression. The lagoon existed during Early , Rava-Russka, Lubelia, Kadobno, South Kimmeridgian. Evaporite lagoon sediments are Kadobno, Verchany, , Stavchany, Didushi- dolomites, anhydrites, gypsum, mudstones, silt- chi, Trostianets, , Rogatin, - stones, sandstones and breccias. Back-reef section , Mala Gorozhanka, Seredniy Majdan and is composed of the Oxfordian – Lower Berriasian other areas. This section formed in the territory of back-reef facies and Lower Kimmeridgian lagoon Early Kimmeridgian lagoon is composed by Lower facies. Gorodok suite (30-40 m thick) composed of Kimmeridgian lagoon facies (Rava-Russka suite) sandy and silty limestones with interlayers of mud- and Upper Kimmeridgian – Early Berriasian back- stones in the bottom. Above lie Rava-Russka suite reef facies (Nyzhniv and Bukivna suites) some- (up to 300 m thick), Nyzhniv suite (about 200 m where with Stavchany suite at the top. Rava-Russka thick) and Bukivna suite (up to 60 m thick). In the suite (20–350 m thick) is represented by mottled Didushychi and South Grynivka areas at the top of (prevailly red) mudstones, siltstones, sandstones, the section lie Upper Berriasian beds of Stavchany gravellites, konglomerates and breccias with anhy- suite (up to 40 m thick) represented by bioclastic drite-dolomite cement with inclusions and beds of sandy and brecciated limestones with macrofauna anhydrites, gypsum and dolomites in the lower part. fragments. Back-reef section lies on the Paleozoic In the upper part this suite is represented by the or Middle Jurassic deposits and is overlapped by succession of gray dolomites and dolomitic lime- Upper Cretaceous, in places by Aptian–Albian. stones, anhydrites, mudstones. Nyzhniv suite (6– Thickness of this section is up to 640 m. 200 m thick) is composed of limestones (dolomitic, Sedimentation of these deposits took place on biomicritic, bioclastic) and dolomites, in places with the back-reef plain with small deeps (to 25-40 m). clay beds, sandy and gravellitic admixture. Bukivna Numerous vestiges of the reef-loving organisms and suite (2–60 m thick) is composed of biomicritic and the inhabitants of the shallow water and stagnant bioclastic limestones, in the upper part iterbedded sea (mollusks, brachiopods, ostracods, bryozoans, by oolitic limestones. Stavchany suite (20–50 m) is sponges, corals, sea–urchins, fish, algae, crayfishes) composed of mudstones with interlayers of sand- and wide development of the warmly water large stones and sandy limestones in the lower part and bentic foraminifers testify about that. Occurrence of is represented by bioclastic limestones sometimes tintinnids marks the transgressive events. with glauconite in the upper part. Lagoon section The section with Oxfordian deposits formed on is often greatly eroded (sometimes to Rava-Russka upper sublittoral of basin was opened in the north suite). It lies on Paleozoic deposits, in places (Lube- east by the wells Rava-Russka-2 and Velyki Mosty-2. lia, Verbizh at other areas) on the Middle Jurassic These deposits are represented by limestones with suite and is overlapped by Upper Cretaceous interlayers of calcareous siltstones and sandstones. or Miocene formations. Thickness of the section is Single shells of sea foraminifers were found only in variable, up to 310 m, decreases to the east. one bed of calcareous siltstones. These rocks con- Early Kimmeridgian lagoon was very salted shal- tain Paleozoic coal and quarzite pebbles – products low-water basin. Lagoon rocks contain only favreins, of destruction of Paleozoic coast. They are over- cianofitus, mollusks, gastropods, ostracods, siliceous lapped by littoral siltstones and sandstones with ve­ foraminifers. In middle of Kimmeridgian lagoon disap- getable vestiges. They lie at the angle of 10–15° and peared because of the global transgression. After that are similar to Middle Jurassic Sokal suite situated in back-reef facies were formed in that area.

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VI type of section (shallow-water) outcrops possible to determine that the main stages of the along the right bank of river Dnister, consists only of sedimentation of carbonate complex took place Nyzhniv and Bukivna suites. Nyzhniv suite is com- under the great influence of the eustatic changes. posed of oncolitic and bioclastic limestones. Bukiv- During Oxfordian a number of transgressive – re- na suite is represented by the mollusc-algal bio- gressive events occured against the long-term herms. This section is overlapped by Cenomanian transgressive background. Forming biohermes by sandstones. Thickness of the section is 5–10 m. sponges at the bottom and by corals and algae Bukivna suite is eroded. above them and oncolitic limestones at the top was After restoring sea conditions during Late Titho- related with the regressive stage after Early Oxford- nian and Early Berriassian the stripe of the small ian and the great sea-level fall in Late Oxfordian. At bioherms (to 15–55 m thick) were formed on the Oxfordian – Kimmeridgian boundary sea-level fall- depth of 25–30 m. Numerous well developed reef- ing to same level resulted in great erosion of bio- loving foraminifers and genetic relation with coral hermes, the sedimentation of mottled rocks at the reef confirm it. bottom of Kimmeridgian formation and isolation VII type of section (outlying) outcrops along the of the evaporate lagoon on the periphery of basin. Dnister banks from Ustia Zelene to Nezvysko (the During Early Kimmeridgian normal sea conditions largest outcrop is near the Budzin and Gorygliady) were restored because of the periodical regres- and was opened by drilling in Lopushna, Korshiv- sive events against the global transgression. Late Ispas, Krasnoilsk, Storozhunets and other areas. Kimmeridgian – Early Tithonian long-term trans- This section was formed in the periphery of Late gression destroyed a lagoon and caused the sedi- Kimmeridgian – Early Tithonian back-reef basin and mentation of limestones with the separate sponge is represented by Nyzhniv suite. Conglomerates (6– bioherms. Deposits of this stage are the most wid- 10 m thick) composed of fragments of Paleozoic gray ened in the region because of the transgression sandstones and dolomites and «old-red» sandstones maximum at the middle of Thitonian. During Late with the Jurassic limestonic and dolomitic cement Tithonian – Early Berriassian sea-level fluctuations lie at the bottom. Over them there are oncoidal and against the global regression took place and barrier micritic limestones (up to 12 m thick) overlapped by coral reef was formed. At the Early and Late Berri- the succession of dolomites, dolomitic and bioclastic assian boundary maximum transgression stopped limestones, marls (up to 60 m thick). In the outcrops reef building in region and formed Upper Berrias- Nyzniv conglomerates lie on the eroded Paleozoic sian mudstone layers. Regressive stage was con- surface. Nyzhniv suite is overlapped by Albian–Ceno- tinued after that till the end of Valanginian. Big re- manian sands or Cenomanian sandstones. Thick- gressive events at the boundary of Berriassian and ness of this section is 65–70 m. Valanginian, Early and Late Valanginian gave rise to Jurassic deposits decrease to the east. In the the forming limestone formations. The next regres- extreme east the littoral Upper Jurassic deposits sions and tectonic processes caused the erosion of were opened in the quarry near the village Korzhova carbonate complex. (r. Zolota Lypa). In that section there is only Nyzhniv suite lied on the eroded surface of Devonian dolo- CONCLUSIONS mites and represented by oolitic limestones inter- The main stages of the sedimentation of Oxfordian – bedded by mudstones. Its thickness is 1,5–2 m. At Valanginian carbonate complex in the Ukrainian the bottom limestones substituted by sandstones Precarpathians were related to eustatic sea-level with pebbles of Paleozoic rocks. Limestones con- chanding: Oxfordian (transgressive – regressive tain the numerous favreins testifying about the se­ events against the long-term transgressive back- dimentation in extreme shallow and changeably salt ground), the Oxfordian – Kimmeridgian boundary water zone. Jurassic rocks are overlapped by Ceno- (sea-level fall to same level), Early Kimmeridgian manian conglomerates, which contain the pebbles (periodical regressive events against the global and boulders of Upper Jurassic limestones formed transgression), Late Kimmeridgian – Early Tithoni- of their wash-out at the beginning of Late Creta- an (long-term transgression), Late Tithonian – Early ceous. The Jurassic surface is generally eroded. Berriassian (great sea-level fluctuations against The main stages of forming carbonate com- the global regression), the boundary of Early and plex. Correlation of the section types and the pa- Late Berriassian (transgressive maximum), Late leoecological conditions of their forming made it Berriassian – Valanginian (regressive stage with

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big regressive events at the boundaries of Berrias- Tithonian), Bukivna (Upper Tithonian – Lower Ber- sian and Valanginian, Early and Late Valanginian). riassian), Stavchany (Upper Berriassian – Valangi­ Stratigrafic correlation of the litofacial formations of nian). Transitional section is presented in the limits the carbonate complex have been carried out. of the replacement of Oxfordian reef and back-reef The main factor of this carbonate complex for­ facies (Rudki and Gorodok suites) and Lower Kim- ming was reef-building processes during Late Ju- meridgian back-reef and lagoon facies (Pidluby and rassic and Early Berriasian. Reef sediments (fore- Rava-Russka suites), overlapped by back-reef Nyzh- reef, reef, back-reef, lagoon facies) are overlapped niv and Bukivna suites with Stavchany suite at the by the Upper Berriassian – Valanginian open shelf top. Lagoon section determined on the territory of deposits. Seven types of the section formed in the Kimmeridgian evaporite lagoon consists of Rava- different zones of paleobasin are fore-reef, reef, Russka, Nuzhniv, in places Bukivna and Stavchany back-reef, transitional, lagoon, shallow-water, out- suites. Shallow-water section formed in the shal- lying. They are characterized by the specific litho- low-water zone of back-reef basin represented logical and paleontological composition. Fore-reef by Nyzhniv and Bukivna suites. Outlying section type of section formed in the deep zone of basin formed in the periphery of Late Kimmerid­gian – consists of the suites – Boniv (Oxfordian), Morantci Early Tithonian back-reef zone is represented by (Kimmeridgian), Karolina (Tithonian – Lower Va- Nyzhniv suite. Model of the sedimentation these langinian). Reef section is composed of Oxfordian deposits is made on the base of the correlation biogerms (Rudki suite) and Kimmeridgian – Ber- of different types of section an in accordance with riasian barrier reef (Opary suite). Back-reef section determined paleoecological conditions and stages consist of the suites – bаck-reef Gorodok (Oxfor­ of sedimentation. dian), Pidluby or lagoon Rava-Russka (lower Kim- Author wish to thank Dr. O.V. Samarska and Dr. meridgian), Nyzhniv (Upper Kimmeridgian – Lower O.V. Anikeyeva for discussions and advices.

REFERENCES REFERENCES Anikeyeva O.V., 2002. Changing of the biocenoses of reef- Анікеєва О. В. Зміна біоценозів рифобудівних організмів building organisms during the Late Jurassic (Ukrainian Pre- на протязі пізньої юри (Передкарпатський прогин) / Аніке- carpathians). The evolution of organic world such as the єва О. В. // Еволюція органічного світу як підґрунтя для ви- base for deside of the problems of stratigraphy. Scientific рішення проблем стратиграфії. – Наук. праці ІГН НАНУ. – К., works of the Institute of Geological sciences NAS of Ukraine. 2002. – С. 46–48. Кyiv, pp. 46-48. (In Ukrainian).

Anikeyeva O.V., 2005. Late Jurassic reefogenic complex of Анікеєва О.В. Верхньоюрський рифогенний комплекс Ukrainian Precarpathians: biolithomicrofacies and stratigraphy. Українського Передкарпаття: біолітомікрофації та страти- The candidat thesis on speciality 04.00.09 – palaeontology графія: автореф. дис… канд. геол. наук: спец. 04.00.09 – and stratigraphy. IGS NAS of Ukraine. Kyiv, 24 p. (In Ukrainian). палеонтологія і стратиграфія. – К., 2005. – 24 с. Zhabina N.M., Anikeyeva O.V., 2003. Evolution of belts of the Жабіна Н. М. Еволюція поясів верхньоюрського карбо- Upper Jurassic carbonate shelf in Ukrainian Precarpathians. натного шельфу на території Українського Передкарпаття / Papers of NAS of Ukraine, No 8, pp. 118–122. (In Ukrainian). Жабіна Н. М., Анікеєва О. В. // Доповіді НАН України. – 2003.– №8. – С.118–122.

Zhabina N.M., Anikeyeva O.V., 2007. The new stratigraphic Жабіна Н.М. Оновлена стратиграфічна схема верхньої scheme of Upper Jurassic-Neocomian of Ukrainian Precar- юри–неокому Українського Передкарпаття / Жабіна Н.М., pathians. Digest of Science proc. UkrDGRI, No 3, pp. 46–56. Анікеєва О.В. // Зб. наук. праць УкрДГРІ. – № 3. – 2007. – С. (In Ukrainian). 46–56. Dulub V. G., Burova М. I., Burov V. S., Vishnjakov I. B., 1986. Объяснительная записка к региональной стратиграфической Explanatory report for the Stratigraphyc scheme of Jurassic схеме юрских отложений Предкарпатского прогиба и deposits of Carpathian Foredeep and Volyno-Podolia out- Волыно-Подольской окраины Восточно-Европейской skirts of the East-European platform платформы. Leningrad, платформы / [В. Г. Дулуб, М. И. Бурова, В. С. Буров, И. Б. VSЕGЕI, 58 p. (In Russian). Вишняков]. – Л.: ВСЕГЕИ, 1986. – 58 с. Dulub V. G., Zhabina N.M., Ogorodnik M. E., Smirnov S.E., Пояснювальна записка до стратиграфічної схеми юрських 2003. Explanatory report for the Stratigraphyc scheme of відкладів Передкарпаття (Стрийський юрський басейн) / Jurassic deposits of Precarpathians (Stryi Jurassic basin). [Дулуб В. Г., Жабіна Н. М., Огороднік М. Є., Смірнов С. Є.]. – , LD UkrDGRI, 30 p. + scheme. (In Ukrainian). Львів: ЛВ УкрДГРІ, 2003. – 30 с.+ схема. Інститут геологічних наук НАН України, Київ, Україна Рецензент: Н.В.Маслун [email protected]

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