Journal articles: 'Callovian'

1

Callomon, John H. "Callovian." Geobios 27 (December 1994): 757–60. http://dx.doi.org/10.1016/s0016-6995(94)80242-4.

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2

Courtinat, Bernard. "Review of the dinoflagellate cyst Stephanelytron Sarjeant 1961 emend." Journal of Micropalaeontology 18, no. 2 (December 1, 1999): 169–82. http://dx.doi.org/10.1144/jm.18.2.169.

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Abstract. The stratigraphic distribution of the Late Callovian to Early Oxfordian dinoflagellate cyst Stephanelytron Sarjeant 1961 emend provides new evidence pertaining to its evolution. Middle and Upper Callovian times favoured the development of speciations to a short-ranging Stephanelytron community with corona(s) in ventral–posterior position (Stephanelytron brontes, S. callovianum, S. ceto and S. tabulophorum) from eurytopic species with antapical coronas (S. caytonense, S. membranoidium, S. redcliffense and S. scarburghense). The former group of species (except S. tabulophorum) may represent an example of peripatric speciation from an unfavourable mutation. The reduced stratigraphic range gives the appearance of an endemic population. The genus Lagenadinium Piel, 1985 is a junior synonym of Stephanelytron Sarjeant, 1961. A new emendation of Stephanelytron, two new combinations (S. callovianum and S. membranoidium) and two new species (?S. brontes and S. ceto) are proposed.

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3

Hoelstad, Torsten. "Palynology of the Middle Jurassic Lower Graben Sand Formation of the U-1 well, Danish Central Trough." Danmarks Geologiske Undersøgelse Serie A 14 (December 1, 1986): 1–25. http://dx.doi.org/10.34194/seriea.v14.7033.

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Twentyone sidewall core samples from the lower 56 metres of the Lower Graben Sand Formation in the U-1 well are described with respect to their kerogen content and microflora in order to gain a better understanding of the depositional environment and the age relations. Based on e.g. the inconsistent dinoflagellate cyst occurrences, marginal marine conditions are concluded. The dinoflagellate cysts Pareodinia prolongata, Acanthaulax senta, Scriniodinium crystallinum, Energlynia acollaris, Wanaea thysanota and Hystrichogonyaulax cladophora and the recovered palynomorph assemblage in general permit an age determination as follows: 21 m Callovian undifferentiated, 7.9 m latest Middle Callovian - earliest Late Callovian, 6.1 m latest Late Callovian and 21 m latest Late Callovian? - earliest Early Oxfordian.

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4

Callomon, John H. "The ammonite succession in the Middle Jurassic of East Greenland." Bulletin of the Geological Society of Denmark 40 (June 3, 1993): 83–113. http://dx.doi.org/10.37570/bgsd-1994-40-03.

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The ammonite sequence in the Middle Jurassic of central East Greenland is the most complete and detailed known in the Arctic so far, and has become a standard of reference for the whole of the Bo real Faunal Province. It is made up of some 37 distinguishable assemblages that characterize a time-ordered succession of discrete faunal horizons. This succession has been pieced together from over 80 recorded sections in Jameson Land lying between Scoresby Sund and Kong Oscars Fjord (70-72°N). It forms the biostratigraphic basis for the regional chronostratigraphy. The faunal assemblages are listed and described by reference to published illustrations in the literature. Faunas 1-23 are of pre-Callovian age and have no elements in common with their contemporaries in the classical regions of Europe. They still cannot be correlated with the European standard pre-Callovian chronozonations. Most of them must be of Bathonian age, although the earliest of them could well be, and probably are, even still Upper Bajocian. The Bathonian-Callovian boundary most probably lies somewhere in faunas 24-26, which closely resemble those of the keppleri horizon at the base of the Callovian. Faunas 27-35 span the rest of th􀁋 Lower Callovian, while faunas 36 and 37 are the only evidence of Middle and Upper Callovian. The ammonites from Jameson Land previously described by Spath (I 932) are revised and assigned to their correct horizons. Of 11 new species, only one is formally named: Kepp/erites vardekloeftensis sp. nov., of latest Bathonian age.

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5

Majidifard, Mahmoud Reza. "Callovian ammonites from Northeastern Iran." Revista Brasileira de Paleontologia 21, no. 1 (May 4, 2018): 17–46. http://dx.doi.org/10.4072/rbp.2018.1.02.

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6

Brovtsyn, A. K., and G. S. Chershneva. "Aerodynamic concentration of callovian clay." Refractories 37, no. 10 (October 1996): 358–61. http://dx.doi.org/10.1007/bf02238694.

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7

Larsen, Michael, and Finn Surlyk. "Shelf-edge delta and slope deposition in the Upper Callovian – Middle Oxfordian Olympen Formation, East Greenland." Geological Survey of Denmark and Greenland (GEUS) Bulletin 1 (October 28, 2003): 931–48. http://dx.doi.org/10.34194/geusb.v1.4695.

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The Upper Bajocian – Upper Volgian succession of the Jameson Land Basin in East Greenland forms an overall transgressive–regressive cycle. The Upper Callovian – Middle Oxfordian Olympen Formation represents the first regressive deposits after maximum flooding in the Middle to early Late Callovian. The formation was deposited during two southwards progradational phases separated by a major drowning event in the Early Oxfordian. The first phase was marked by incoming of massive slope and base-of-slope sand (Athene Member), but the delta front and top did not reach the area of present-day exposure. The second phase was initiated by deposition of a thick mud succession (Hades Member) indicating that the delta had shifted far to the north during the drowning event. Southwards progradation of the delta was heralded by gully erosion and the deposition of lenticular bodies of massive slope sand; on this occasion, medium- and largescale cross-bedded sand of the delta front and top (Zeus Member) reached the area. The boundary between Middle–Upper Callovian mudstones in the upper part of the underlying Fossilbjerget Formation and the Upper Callovian Athene Member sandstones formed at the turn-around point between sea-level rise and fall. The Athene Member sandstones are interpreted as an undifferentiated falling stage – lowstand systems tract and span a sequence boundary. The top of the Athene Member is the basinal correlative of the transgressive surface. The basal few metres of the overlying Hades Member mudstones represent the transgressive systems tract and a level with organic-rich mudstones is interpreted to represent the maximum flooding zone. The remainder of the Hades Member and the slope sandstones are assigned to the highstand systems tract. The succeeding cross-bedded delta front sandstones of the Zeus Member are placed in the falling stage systems tract and their sharp base is interpreted as a marine regressive surface of erosion. Comparison of this history with published sea-level curves suggests that the short term changes may be eustatic in origin including the Middle Callovian maximum flooding (K. jason – lower P. athleta Chronozones), Late Callovian regression (P. athleta – Q. lamberti Chronozones), latest Callovian – Early Oxfordian flooding (Q. mariae – C. cordatum Chronozones) and late Early – Middle Oxfordian regression (C. densiplicatum Chronozone).

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8

Walley, C. D. "Depositional history of southern Tunisia and northwestern Libya in Mid and Late Jurassic time." Geological Magazine 122, no. 3 (May 1985): 233–47. http://dx.doi.org/10.1017/s0016756800031447.

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AbstractThe good exposures of virtually undeformed Callovian and Oxfordian strata along the Djeffara escarpment of southern Tunisia and northwestern Libya have allowed analysis of regional depositional history during this time.A number of lithostratigraphic problems are considered. In Tunisia, the Foum Tatahouine Formation is subdivided into members and in Libya some of the stratigraphic issues are clarified. A correlation between the two sequences is proposed. The widely claimed aeolian origin for the Libyan Chameau Mort Sandstone is rejected.The depositional patterns of the Callovian and Oxfordian strata are described in the context of Mid and Late Jurassic sedimentation in the eastern Ghadames basin of the African craton. After a regressive Bathonian sequence, transgressive conditions commenced in Early Callovian time. In a series of continental–marine cycles, this transgressive sequence culminated in widespread shallow, restricted-marine micritic deposition. A regression in Late Callovian time resulted in emergence marked by a thin but widespread calcrete horizon. In Mid? Oxfordian time a renewed transgression brought in open marine, high-energy, shallow-water carbonates. Later, regressive conditions returned, leading to increasing restriction, and latest Jurassic time saw the first signs of the fluvio-deltaic deposition that was to dominate the region in Early Cretaceous time.

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9

Veenstra, E. "RIFT AND DRIFT IN THE DAMPIER SUB-BASIN, A SEISMIC AND STRUCTURAL INTERPRETATION." APPEA Journal 25, no. 1 (1985): 177. http://dx.doi.org/10.1071/aj84016.

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Quality improvements in marine reflection seismic data over recent years have lead to a better understanding of the relationships between seismo-stratigraphical sequences present in the Dampier Sub-basin and those in adjacent areas. The "drift-onset" unconformity, which separates the syntectonic rift sequence from the post-tectonic drift sequence, can now be seismically recognised as a single unfaulted surface. Previously this unconformity was interpreted to be faulted. In places this surface had some 2400 m of palaeotopography in the form of an escarpment. This escarpment was formed by tectonic movements and subsequent erosion some time in the Callovian, probably as a consequence of the opening of the Indian Ocean.The presence of Callovian and Upper Jurassic marine sands on the Rankin Platform shows that the Rankin Platform was in places submerged during Callovian and Upper Jurassic times. Furthermore, the Dampier Sub- basin must have been more than 2000 m deep immediately following the causal tectonic event. The escarpment was rapidly buried, with 1200 m of sediments locally deposited by the end of the Callovian and was finally buried by Neocomian times. Thereafter the Rankin Platform and Dampier Sub-basin have subsided.

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10

Halder, K., and S. Bardhan. "The fleeting genus Cymatonautilus (Nautiloidea): new record from the Jurassic Charl Formation, Kutch, India." Canadian Journal of Earth Sciences 33, no. 7 (July 1, 1996): 1007–10. http://dx.doi.org/10.1139/e96-076.

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Cymatonautilus is a new record from Kutch with precise stratigraphic background. Being a temporally restricted but geographically widely distributed genus, Cymatonautilus is considered as a fleeting taxon. It cryptically appeared during the latest early Callovian and survived only up to the middle Callovian, but dispersed rapidly through a long belt on both sides of the Tethys. Its systematic position is revised, and derivation from paracenoceratid lineage is suggested.

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11

Matveyev, A. V., and D. S. Bondarev. "CALCAREOUS NANNOPLANKTON OF CALLOVIAN OF UKRAINE." Collection of Scientific Works of the Institute of Geological Sciences of the NAS of Ukraine 6 (January 10, 2013): 65–67. http://dx.doi.org/10.30836/igs.2522-9753.2013.147151.

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12

Levchuk, L. K. "Callovian foraminiferal assemblages in West Siberia." Russian Geology and Geophysics 50, no. 6 (June 2009): 562–71. http://dx.doi.org/10.1016/j.rgg.2008.12.002.

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13

Marinov, Vladimir, Alexander Alifirov, Alexander Kudamanov, and Varvara Bumagina. "CALLOVEAN AND UPPER JURASSIC CONSTRUCTION ON EM-EKOVSKOE FIELD (WESTERN SIBERIA)." Interexpo GEO-Siberia 2, no. 1 (2019): 87–94. http://dx.doi.org/10.33764/2618-981x-2019-2-1-87-94.

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The results of litho-bio-stratigraphic studies of Callovian and Upper Jurassic of the Em-Ega oil field (Western Siberia) are presented. The formation of sediments took place in the sea basin and had a pulsating character. Episodes of sediment accumulation were replaced by periods of a sharp shortage of terrigenous material. The main stages of the arrival of terrigenous material were Callovian, Middle and Late Oxfordian, Early Kimmeridgian and Middle and Late Volgian. In Early Oxfordian, Late Kimmeridgian, Early Volgian deposits did not accumulate.

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14

Darngawn, Jehova L., Satish J. Patel, Jaquilin K. Joseph, and Apuva D. Shitole. "Genetic sequence stratigraphy on the basis of ichnology for the Middle Jurassic basin margin succession of Chorar Island (eastern Kachchh Basin, western India)." Geologos 25, no. 1 (April 1, 2019): 31–41. http://dx.doi.org/10.2478/logos-2019-0003.

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Abstract Synrift basin margin successions are greatly influenced by eustatic sea level changes, tectonics and accommodation space filled in by sediments. The Middle Jurassic (Bajocian–Callovian) of Chorar Island (western India) comprises a ~109-m-thick synrift basin margin succession of clastic, non-clastic and mixed siliciclastic-carbonate rocks which are here analysed and categorised into nine lithofacies. The succession is bioturbated to varying intensities; 16 identified ichnogenera can be assigned to environmentally related groups of five trace fossil assemblages, which include Gyrochorte, Hillichnus, Rhizocorallium, Skolithos and Thalassinoides. These ichnoassemblages document the Skolithos and Cruziana Ichnofacies which marks a change in energy conditions, sedimentation dispersal patterns and bathymetry in a shallow-marine environment. The Bajocian–Callovian succession is further analysed on the basis of sedimentological and ichnological data that show two genetic sequences consisting of Transgressive Systems Tract and Highstand Systems Tract bounded by Maximum Flooding Surface. The synrift basin margin succession of the Middle Jurassic of Chorar Island shows cyclicity in deposition; the Bajocian–Bathonian succession represents progradational to retrogradational coastlines, while the Callovian succession documents an aggrading progradational coastline.

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15

Dzyuba, Oksana S., Anna A. Goryacheva, Dmitry A. Ruban, Victoria V. Gnezdilova, and Pavel P. Zayats. "New data on Callovian (Middle Jurassic) belemnites and palynomorphs from the Northern Caucasus, southwest Russia." Geologos 22, no. 1 (March 1, 2016): 49–59. http://dx.doi.org/10.1515/logos-2016-0004.

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Abstract Palaeontological data on the Caucasus are highly important for large-scale stratigraphical and palaeobiogeographical assessment of the northern Tethyan margin, but this information is often scarce and not available in English. Field studies in the Northern Caucasus have now permitted to amass some new data. Two belemnite species are described from the stratotype section of the Kamennomostskaja Formation (Callovian, Middle Jurassic) near the town of Kamennomostskij in Adygeja (Northern Caucasus). These are Belemnopsis subhastata (von Zieten, 1831) and Rhopaloteuthis ominosa Gustomesov, 1968. The latter is a rare species, and the present find allows new insights into its taxonomy. A palyno-logical analysis of the belemnite-bearing sample was carried out, and a diverse assemblage of dinocysts, acritarchs and prasinophytes, plus pollen and spores recognised. The most abundant palynomorphs are Micrhystridium and Classopollis. Data on belemnites coupled with those on palynomorphs indicate the early Callovian age of the sample level. This interpretation differs slightly from previous conclusions based on ammonites and dinocysts. If this age is correct, the degree of condensation of Callovian deposits in the section studied was lesser than previously assumed.

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16

Marinov, V. A., A. S. Alifirov, V. A. Bumagina, A. E. Igolnikov, A. I. Kudamanov, E. B. Avramenko, M. A. Grishchenko, and M. D. Smyshlyaeva. "STRATIGRAPHY AND FORMATION CONDITIONS OF CALLOVIAN AND UPPER JURASSIC DEPOSITS OF THE CENTRAL PART OF THE KAZYM-KONDA REGION (WEST SIBERIA)." Geology and mineral resources of Siberia, no. 2 (2021): 3–16. http://dx.doi.org/10.20403/2078-0575-2021-2-3-16.

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The results of stratigraphic and facies studies of the Callovian and Upper Jurassic of the Kazym-Konda facies region (West Siberia) are presented. The sequence of subdivisions of the boreal zonal standard is established. The section is composed of rocks with predominantly shallow marine genesis; their composition depended on sedimentation cyclicity and sea level fluctuations. The highest incoming rates of sedimentary material were associated with transgressive episodes in the Callovian, Middle Oxfordian and Middle Volgian. Stratigraphic breaks and periods of deficient sedimentation in the Late Oxfordian, Kimmeridgian, Early Volgian and Late Volgian correspond to regressive episodes in the section.

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17

Shevchuk, O. A. "Dinocysts in Callovian Deposits of Central Ukraine." International Journal on Algae 22, no. 3 (2020): 279–86. http://dx.doi.org/10.1615/interjalgae.v22.i3.70.

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18

Robertson, A. H. F., and J. G. Ogg. "Palaeoceanographic setting of the Callovian North Atlantic." Geological Society, London, Special Publications 21, no. 1 (1986): 283–98. http://dx.doi.org/10.1144/gsl.sp.1986.021.01.21.

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19

Ware, Martin, and Robin C. Whatley. "The identity of the Middle Jurassic Ostracoda Fastigatocythere juglandica (Jones) and Lophocythere fulgurata (Jones & Sherborn): a solution to an old enigma." Journal of Micropalaeontology 21, no. 2 (December 1, 2002): 155–66. http://dx.doi.org/10.1144/jm.21.2.155.

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Abstract. The Upper Bathonian and Lower Callovian ostracod species Fastigatocythere juglandica (Jones, 1884) is shown to comprise a total of five subspecies. Of these, F. juglandica juglandica, F. juglandica major (Jones & Sherborn, 1888) and F. juglandica postrotunda subsp. nov., described as new herein, are all confined to the Upper Bathonian. Lophocythere fulgurata (Jones & Sherborn, 1888) is demonstrated to be an instar of F. juglandica major. Fastigatocythere juglandica degenerata subsp. nov., described as new herein and F. juglandica rugosa Weinholz comb. nov., both confined to the Lower Callovian, extend the known range of the species into that stage for the first time.

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20

Stepanov, I. A., A. Yu Kazansky, D. N. Kiselev, L. R. Kosareva, M. A. Rogov, E. M. Tesakova, E. V. Shchepetova, and Ya A. Shurupova. "Potencial of rock-magnetic methods in paleoecological reconstructions: case study of Mikhailovtsement reference section (Ryazan region)." Moscow University Bulletin. Series 4. Geology, no. 2 (April 28, 2019): 30–38. http://dx.doi.org/10.33623/0579-9406-2019-2-30-38.

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On the basis of detailed, combined rock-magnetic, lithological, and micropaleontological study of the Mikhailovtsement section of the Moscow syneclise (Ryazan region), the fluctuations in Central Russian Sea level in Callovian–Early Oxfordian were reconstructed. According to the variations of rock-magnetic parameters over the section, seven rock-magnetic intervals were established which correspond to different stages of basin evolution. These stages are compared with sea level fluctuations established on the basis of changes in the lithology of rocks and the ostracod complexes. In general, the nature of sea level change in Callovian–Oxfordian, revealed by combination of the methods during the study of Mikhailovtsement section coincides with global trend.

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21

Nagornaya, Olga Vyacheslavovna, and Antonina Valentinovna Golovastikova. "Soil Algae and mosses role in biocenoses formation in the tailings of Mikhailovsky Mining and Beneficiation Plant of Kursk Magnetic Anomaly." Samara Journal of Science 7, no. 1 (March 1, 2018): 87–91. http://dx.doi.org/10.17816/snv201871116.

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The paper presents the results of studies investigating the role of representatives of Algae and Bryophyta divisions in the composition of biocenoses dumps loess-like loam and clay of the Callovian of different ages (5-, 15-, 25 years) of Mikhailovsky Mining and Beneficiation Plant of Kursk Magnetic Anomaly. The author considers the role of soil Algae and mosses as indicators of biocenosis changes in connection with the peculiarities of the lithological framework and age of the dumps. It is proved that successione changes in communities of soil Algae and mosses coincide with succesional changes in the phytocenoses of the dumps in General. Studies have shown that the primary satelitales dumps are the representatives of the department of blue-green Algae Cyanophyta. They form a mono community in 5 year dumps clay of the Callovian and dominate in 5 year dumps. Further formation of the algae Alps in all types of studied rocks is of zonal type. The first of the mossy plants of the Bryophyta dumps division inhabits Ceratodon purpureus (Hedw.). It is the dominant species and persists on all breeds up to the age of 25 as the least demanding of the substrate. Further, the formation of the community of mosses is on a zonal type and lesavignon loam, on average, 15 years faster. It is found that algal communities and bryophytes cenoses form at different speeds on the soil stockpiles. It has been calculated that the stabilization of Algae cenoses will require about 19 years for the Quaternary loess and 32 years on the clay of the Callovian. Stabilization of the community of moss will require about 35 years for the loess and about 70 years on the clay of the Callovian.

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22

Pattillo, J., and P. J. Nicholls. "A TECTONOSTRATIGRAPHIC FRAMEWORK FOR THE VULCAN GRABEN, TIMOR SEA REGION." APPEA Journal 30, no. 1 (1990): 27. http://dx.doi.org/10.1071/aj89002.

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The Vulcan Graben is a northeast trending intracratonic rift system developed in response to Late Jurassic-Early Cretaceous break-up of the Australian northwest continental margin. A depositional sequence study was undertaken of the Vulcan Graben and the surrounding area, incorporating regional well and seismic data. From this a tectonostratigraphic framework has been established. Three megasequences are defined in relation to the Callovian rift episode; Pre-rift (pre-Callovian), Syn-rift (Callovian to Valanginian) and Post-rift (Valanginian to Present Day), each consisting of a number of discrete depositional sequences. This study has clarified the structural and stratigraphic evolution of the region, enabling development of dynamic depositional models. These models constrain the vertical and lateral facies distribution across the region, thus providing a powerful basis for petroleum exploration, including prediction of reservoir, seal and source rocks.Significantly, while Late Jurassic rifting was initiated in the Late Callovian, imprinting a NE-SW oriented grain, a second major tectonic episode occurred in the Kimmeridgian trending ENE-WSW, which generated the dominant regional structural architecture. Recognition of this Kimmeridgian event has considerable impact on the successful delineation of structural plays within the region and provided significant control on syn-rift facies distribution and consequently stratigraphic play potential within the Vulcan Graben. Stratigraphic and structural relationships clearly indicate that rifting ceased in the middle Valanginian, followed by post- rift thermal subsidence and consequent transgression and inundation of the Vulcan Graben. The intra-Valanginian event represents a regional disconformity rather than a major tectonic unconformity and defines the boundary between the syn- and post-rift megasequences. This is consistent with the revised Valanginian date for the onset of sea-floor spreading in the Argo Abyssal Plain.A revised lithostratigraphic nomenclature is proposed for the region which complements the resolution achieved by depositional sequence mapping.

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23

Basha, Sa'd H. S. "Callovian-Oxfordian foraminifera and ostracodes from northwestern Jordan." Neues Jahrbuch für Geologie und Paläontologie - Monatshefte 1997, no. 10 (January 10, 1997): 585–95. http://dx.doi.org/10.1127/njgpm/1997/1997/585.

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24

Danelian, Taniel, Patrick De Wever, and Michel Durand-Delga. "Revised radiolarian ages for the sedimentary cover of the Balagne ophiolite (Corsica, France). Implications for the palaeoenvironmental evolution of the Balano-Ligurian margin." Bulletin de la Société Géologique de France 179, no. 3 (May 1, 2008): 289–96. http://dx.doi.org/10.2113/gssgfbull.179.3.289.

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Abstract The age of radiolarites covering the Balagne ophiolite is reassessed based on new and revised radiolarian fossil evidence. The oldest radiolarian cherts are dated as upper Bathonian-lower Callovian in two tectonic units: San Colombano and Novella. These are amongst the oldest ages available so far from ophiolites of the Ligurian ocean. An important stratigraphic gap, spanning the Callovian-early Kimmeridgian interval, is specified between radiolarites and the overlying (and locally gullying) San Colombano shallow-water limestones (sub-unit I). We can now specify that radiolarian ooze accumulated until the late Kimmeridgian in the distal parts of the Balagne margin (sub-unit SC III and Novella unit), while fragments of Hercynian basement fell into the Balagne basin during the late Kimmeridgian-Tithonian.

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25

Ruban, Dmitry A. "The siliciclastics/carbonates shift in the Jurassic of the Western Caucasus (central northern Neo-Tethys): reconsidering research over the last 50 years." Geologos 25, no. 2 (August 1, 2019): 153–62. http://dx.doi.org/10.2478/logos-2019-0014.

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Abstract A chain of carbonate platforms evolved in the northern Neo-Tethys during the Late Jurassic, but current knowledge remains incomplete as long as data from several larger regions, such as the Western Caucasus, are not included. In order to fill this gap, it is here suggested to reconsider the information accumulated chiefly during Soviet times. Although these data are too general, they still matter with regard to some regional characteristics and tentative interpretations. Available data on the spatio-temporal distribution of Bajocian-Callovian sedimentary rocks are summarised in a novel way which permits documentation of depositional trends at six representative localities in the Western Caucasus. The extent of the carbonate platform increased at two localities since the Late Callovian and at a third since the Middle Oxfordian. Three additional sites were characterised either by non-deposition or deep-marine sedimentation. The onset of carbonate platform development marked a remarkable shift from chiefly siliciclastic to carbonate deposition, although this event was not sudden everywhere. The Bathonian pulse of tectonic activity, coupled with the eustatic sea level rise, allowed shelves to expand during the Callovian-Oxfordian, with a reduction in siliciclastic input from islands and sea-water that became well oxygenated and warmer. These conditions were conducive to biogenic carbonate production, allowing the carbonate platform to expand subsequently.

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26

Piasecki, Stefan, and Lars Stemmerik. "Jurassic dinoflagellate cysts from Hochstetter Forland, North-East Greenland." Geological Survey of Denmark and Greenland (GEUS) Bulletin 5 (November 1, 2004): 89–97. http://dx.doi.org/10.34194/geusb.v5.4809.

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Three sections in Hochstetter Forland, North-East Greenland, referred to the Jurassic Payer Dal and Bernbjerg Formations, have been analysed for dinoflagellate cysts. The dinoflagellate cysts, new finds of ammonites and previously recorded marine faunas form the basis for improved dating of the succession. The basal strata of the Payer Dal Formation at Kulhus is here dated as Late Callovian, Peltoceras athleta Chronozone, based on the presence of relatively abundant Limbicysta bjaerkei, Mendicodinium groenlandicum, Rhychoniopsis cladophora and Tubotuberella dangeardii in an otherwise poor Upper Callovian dinoflagellate assemblage. Ammonites have not been recorded from these strata. The upper Payer Dal Formation at Agnetesøelven is dated as Late Oxfordian, Amoeboceras glosense – Amoeboceras serratum Chronozones, based on the presence of Sciniodinium crystallinum, together with Cribroperidinium granuligera and Stephanelytron sp. The age is in accordance with ammonites present in the uppermost part of the formation at Søndre Muslingebjerg. New ammonites in the Bernbjerg Formation at Agnetesøelven together with dinoflagellate cysts indicate an earliest Kimmeridgian age, Rasenia cymodoce and Aulacostephanoides mutabilis Chronozones. The Upper Callovian dinoflagellate cysts from Hochstetter Forland belong to a local brackish to marginal marine assemblage, which only allows a fairly broad correlation to coeval assemblages in central East Greenland. In contrast, the Oxfordian and Kimmeridgian assemblages are fully marine and can be correlated from Milne Land in central East Greenland via Hochstetter Forland to Peary Land in eastern North Greenland.

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27

Scherreiks, R., G. Meléndez, M. Bouldagher-Fadel, G. Fermeli, and D. Bosence. "THE CALLOVIAN UNCONFORMITY AND THE OPHIOLITE OBDUCTION ONTO THE PELAGONIAN CARBONATE PLATFORM OF THE INTERNAL HELLENIDES." Bulletin of the Geological Society of Greece 50, no. 1 (July 27, 2017): 144. http://dx.doi.org/10.12681/bgsg.11713.

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The carbonate-platform-complex and the oceanic formations of the central Pelagonian zone of the Hellenides evolved in response to a sequence of plate tectonic episodes of ocean spreading, plate convergence and ophiolite obduction. The biostratigraphies of the carbonate platform and the oceanic successions, show that the Triassic-Early Jurassic platform was coeval with an ocean where pillow basalts and radiolarian cherts were being deposited. After convergence began during late Early- Jurassic - Middle Jurassic time, the oceanic leading edge of the Pelagonian plate was subducted beneath the leading edge of the oceanic, overriding plate. The platform subsided while a supra-subduction, volcanic-island-arc evolved. Biostratigraphic and geochemical evidence shows that the platform and the oceanic floor, temporarily became subaerially exposed during Callovian time. This “Callovian event” is suggested to have taken place as oceanic lithosphere first made compressional, tectonic contact with the carbonate platform, initiating a basal detachment fault, along which the platform was thrust upwards. The central Pelagonian zone became an extensive land area that was supplied with laterite from an ophiolite highland. A similar emergence of Vardar ophiolite most likely took place in the Guevgueli area. The Callovian emergence shows that the initial ophiolite obduction onto the platform took place about 25 million years before the final emplacement of the ophiolite during Valanginian time.

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Knyazev, V. G., S. V. Meledina, and A. S. Alifirov. "MONOGRAPHIC DESCRIPTION OF THE MIDDLE CALLOVIAN GENUS PROTOLONGAEVICERAS." Geology and mineral resources of Siberia, no. 2 (2019): 16–23. http://dx.doi.org/10.20403/2078-0575-2019-2-16-23.

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Page, K. N. "A stratigraphical revision for the English Lower Callovian." Proceedings of the Geologists' Association 100, no. 3 (January 1989): 363–82. http://dx.doi.org/10.1016/s0016-7878(89)80055-0.

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Salamon, Mariusz A. "The callovian (Middle Jurassic) crinoids from northern Lithuania." Paläontologische Zeitschrift 82, no. 3 (September 2008): 269–78. http://dx.doi.org/10.1007/bf02988894.

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Tesakova, E. M., A. S. Strezh, and D. B. Gulyaev. "New lower Callovian ostracodes from the Kursk Region." Paleontological Journal 43, no. 3 (May 2009): 258–71. http://dx.doi.org/10.1134/s0031030109030034.

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Alifirov, A. S., and V. G. Knyazev. "The Upper Callovian Ammonites Cardioceratidae from Northern Siberia." Stratigraphy and Geological Correlation 28, no. 5 (September 2020): 493–513. http://dx.doi.org/10.1134/s0869593820050032.

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Mönnig, Eckhard. "The evolution of Oppel's ‘Macrocephalusbett’ (Callovian, Middle Jurassic)." Lethaia 50, no. 3 (May 16, 2017): 356–68. http://dx.doi.org/10.1111/let.12220.

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Ewin, Timothy A. M., and Ben Thuy. "Brittle stars from the British Oxford Clay: unexpected ophiuroid diversity on Jurassic sublittoral mud bottoms." Journal of Paleontology 91, no. 4 (April 3, 2017): 781–98. http://dx.doi.org/10.1017/jpa.2016.162.

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AbstractThree new ophiuran species, Enakomusium whymanae n. sp., Aspidophiura? seren n. sp., and Ophiotitanos smithi n. sp., and an unnamed specimen assignable to the genus Dermocoma are described from the Callovian to Oxfordian Oxford Clay Formation of Great Britain. These determinations are based on new finds and a critical reassessment of historic specimens. The Oxford Clay ophiuroids represent two loose assemblages, one from the middle Callovian Peterborough Member and the other from the lower Oxfordian Weymouth Member. Both assemblages accord well with coeval midshelf mud bottom ophiuroid communities in terms of taxonomic composition and relative abundance of taxa. The British Oxford Clay ophiuroids are particularly significant as they are one of the rare instances where multiple species are represented, almost exclusively, by exceptionally preserved articulated skeletons. This provides an important window into the understanding of mid-Upper Jurassic ophiuroid paleobiology.

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Matlaj, L. M. "Calcareous nannoplankton from Callovian deposits of Kanev's dislocation region." Reports of the National Academy of Sciences of Ukraine, no. 10 (November 16, 2016): 54–59. http://dx.doi.org/10.15407/dopovidi2016.10.054.

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Hewitt, Roger A., and Ross L. Judd. "Buoyancy calculations and ecology of Callovian (Jurassic) cylindroteuthid belemnites." Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 211, no. 1-2 (January 29, 1999): 89–112. http://dx.doi.org/10.1127/njgpa/211/1999/89.

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Damborenea, Susana E. "Middle Jurassic inoceramids from Argentina." Journal of Paleontology 64, no. 5 (September 1990): 736–59. http://dx.doi.org/10.1017/s0022336000018965.

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Extensive collections from stratigraphically controlled sections allow reassessment and systematic revision of Middle Jurassic inoceramids from Argentina. Two species are doubtfully referred to Parainoceramus Voronetz, including P.? westermanni n. sp. Five species of Retroceramus Koshelkina, including R. cf. R. marwicki (Speden), R. patagonicus (Philippi) and R. stehni n. sp., are present. The Bajocian–early Callovian species of Retroceramus show strong affinities with Aalenian–Bathonian inoceramids from the Northern Hemisphere, and also with the South Pacific forms of the galoi–haasti group of Heterian–Ohauan age, except for minor differences in outline, ornamentation, and the umbonal region.The time range of each species in Argentina was determined by associated ammonoids. There is strong morphological evidence, supported by the stratigraphic distribution of species, that Retroceramus cf. R. marwicki, R. patagonicus, and R. stehni belong to a single clade, which developed from the late Bajocian to the early Callovian in the Andean region.

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Pott, Christian, and Baoyu Jiang. "Plant remains from the Middle–Late Jurassic Daohugou site of the Yanliao Biota in Inner Mongolia, China." Acta Palaeobotanica 57, no. 2 (December 1, 2017): 185–222. http://dx.doi.org/10.1515/acpa-2017-0012.

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AbstractA late Middle–early Late Jurassic fossil plant assemblage recently excavated from two Callovian–Oxfordian sites in the vicinity of the Daohugou fossil locality in eastern Inner Mongolia, China, was analysed in detail. The Daohugou fossil assemblage is part of the Callovian–Kimmeridgian Yanliao Biota of north-eastern China. Most major plant groups thriving at that time could be recognized. These include ferns, caytonialeans, bennettites, ginkgophytes, czekanowskialeans and conifers. All fossils were identified and compared with species from adjacent coeval floras. Considering additional material from three collections housed at major palaeontological institutions in Beijing, Nanjing and Pingyi, and a recent account in a comprehensive book on the Daohugou Biota, the diversity of the assemblage is completed by algae, mosses, lycophytes, sphenophytes and putative cycads. The assemblage is dominated by tall-growing gymnosperms such as ginkgophytes, czekanowskialeans and bennettites, while seed ferns, ferns and other water- or moisture-bound groups such as algae, mosses, sphenophytes and lycophytes are represented by only very few fragmentary remains. The floral composition underlines the Callovian–Kimmeridgian age of the Yanliao Biota. The Daohugou/Yanliao flora is a typical member of the Middle to Late JurassicConiopteris-Phoenicopsisassemblage of north-eastern China, differing from the Early Cretaceous Jehol flora. Both floras probably belong to the same cycle of volcanism and sedimentation, although the Daohugou Bed is older than the Yixian Formation. The Yanliao fossil assemblage is placed in a larger palaeo-phytogeographical context and its relationships with Middle–Late Jurassic floras from north-eastern China, north-eastern and eastern Siberia and Japan are evaluated.

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Gabdullin, R. R., N. V. Badulina, E. A. Bakai, E. V. Rubtsova, A. Yu Yurchenko, E. V. Karpova, A. V. Ivanov, et al. "COMPOSITION AND ORIGIN OF CALLOVIAN-OXFORDIAN DEPOSITS OF THE SUDAK BAY (CRIMEA)." Moscow University Bulletin. Series 4. Geology, no. 3 (June 28, 2018): 25–40. http://dx.doi.org/10.33623/0579-9406-2018-3-25-40.

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Composition and origin of Callovian–Oxfordian deposits of the Sudak Bay based upon generalizations of our own results and analysis of published and unpublished data were specified. A botanic feature for geological prospecting of Oxfordian limestones was used for the first time.

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Djeric, Nevenka, Natasa Gerzina, and Dragan Simic. "Middle Jurassic radiolarian assemblages from Zlatar Mt. (SW Serbia)." Annales g?ologiques de la Peninsule balkanique, no. 71 (2010): 119–25. http://dx.doi.org/10.2298/gabp1071119d.

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Detailed micropalaeontological research of Jurassic siliceous rocks was performed at the locality Komarani on the eastern flanks of the area of Mt. Zlatar in SW Serbia. According to the determined radiolarian associations, the investigated radiolarites are of Late Bajocian to Early Callovian age.

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Shevchuk, O. A., О. D. Veklych, and Yu B. Dorotyak. "MICROFORAMINIFERS OF THE CALLOVIAN AND CRETACEOUS SEDIMENTS OF UKRAINE." Geological Journal, no. 2 (June 11, 2015): 57–70. http://dx.doi.org/10.30836/igs.1025-6814.2015.2.139605.

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Riccardi, Alberto C. "Callovian and Oxfordian (Jurassic) teuthids (Coleoidea, Cephalopoda) from Chile." Journal of Paleontology 90, no. 5 (September 2016): 910–22. http://dx.doi.org/10.1017/jpa.2016.110.

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AbstractColeoid specimens from the Jurassic of northern Chile are included in two different species ofTrachyteuthis, i.e.,T. covacevichiFuchs and Schultze, 2008 andT. chilensisn. sp., and in a new genus and a new species,Pseudoteudopsis perezin. gen. n. sp. The specimens described and figured are from two different areas in northern Chile. Those referred toPseudoteudopsis perezin. gen. n. sp. came from a locality north of Calama and are associated with ammonites indicating the lower Callovian uppermostbodenbenderito lowermostproximumzones (≈gracilisStandard Zone) of the Andean ammonite zonation. Those described asT. covacevichiandT. chilensisn. sp. came from the Cordillera de Domeyko, northeast of Taltal, and are associated with ammonites indicating the middle OxfordiantransversariumZone.

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JANA, S. K., S. BARDHAN, and K. HALDER. "EUCYCLOCERATIN AMMONITES FROM THE CALLOVIAN CHARI FORMATION, KUTCH, INDIA." Palaeontology 48, no. 4 (July 2005): 883–924. http://dx.doi.org/10.1111/j.1475-4983.2005.00483.x.

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Jain, Sreepat, and Ahmed Awad Abdelhady. "Paleobiogeography of the Middle Jurassic (Bathonian-Callovian) benthic foraminifera." Marine Micropaleontology 161 (December 2020): 101922. http://dx.doi.org/10.1016/j.marmicro.2020.101922.

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Knyazev, V. G., S. V. Meledina, and A. S. Alifirov. "The Middle Callovian of Siberia: Ammonites and Zonal Division." Stratigraphy and Geological Correlation 28, no. 3 (May 2020): 263–80. http://dx.doi.org/10.1134/s0869593820030053.

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Tesakova, E. M., and L. A. Glinskikh. "Callovian Ostracods of Central Dagestan: Biostratigraphy, Paleoecology, and Chorology." Stratigraphy and Geological Correlation 28, no. 4 (July 2020): 402–15. http://dx.doi.org/10.1134/s0869593820040097.

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Westermann, Gerd E. G., Neville Hudson, and Jack Grant‐Mackie. "New Jurassic Ammonitina from New Zealand: Bathonian‐Callovian Eurycephalitinae." New Zealand Journal of Geology and Geophysics 45, no. 4 (December 2002): 499–525. http://dx.doi.org/10.1080/00288306.2002.9514988.

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48

Gaboreau, S., F. Claret, C. Crouzet, E. Giffaut, and Ch Tournassat. "Caesium uptake by Callovian–Oxfordian clayrock under alkaline perturbation." Applied Geochemistry 27, no. 6 (June 2012): 1194–201. http://dx.doi.org/10.1016/j.apgeochem.2012.02.002.

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Gasparini, Zulma, Patrick Vignaud, and Guillermo Chong. "The Jurassic Thalattosuchia (Crocodyliformes) of Chile; a paleobiogeographic approach." Bulletin de la Société Géologique de France 171, no. 6 (November 1, 2000): 657–64. http://dx.doi.org/10.2113/171.6.657.

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Abstract The thalattosuchian fossils from the Jurassic of Chile are revised. Some specimens, dating from the Lower Lias (Sinemurian), are the oldest known thalattosuchians, but are too fragmentary to establish a precise taxonomic placement. New specimen related to the genus Metriorhynchus is described from the lower Bajocian. It is the oldest representative of the genus and fills an important gap in our knowledge of the paleogeographic history of this group. Other new cranial fragments, related to the Callovian species Metriorhynchus casamiquelai, are described and this species is revised in the light of new studies on the intraspecific variability in extant crocodilians. Up until now, the known distribution of Liassic Thalattosuchia suggested a circumpacific distribution with minimally episodic passages through the Caribbean Corridor. Nevertheless, the close affinities between the South American and the European Metriorhynchidae from the Callovian to the Tithonian suggest the possibility that more and more frequent communications were made via the Caribbean Corridor. The new data corroborate the hypothesis formulated from the invertebrate faunas.

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Tchoumatchenco, Platon, Dragoman Rabrenovic, Barbara Radulovic, and Vladan Radulovic. "Trans-border (east Serbia/west Bulgaria) correlation of the Jurassic sediments: Main Jurassic paleogeographic units." Annales g?ologiques de la Peninsule balkanique, no. 67 (2006): 13–17. http://dx.doi.org/10.2298/gabp0667013t.

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In the region across the Serbian/Bulgarian state border, there are individualized 5 Jurassic paleogeographic units (from West to East): (1) the Thracian Massif Unit without Jurassic sediments; (2) the Luznica-Koniavo Unit - partially with Liassic in Grsten facies and with deep water Middle Callovian-Kimmeridgian (p. p) sediments of the type "ammonitico rosso", and Upper Kimmeridgian-Tithonian siliciclastics flysch; (3) The Getic Unit subdivided into two subunits - the Western Getic Sub-Uni - without Lower Jurassic sediments and the Eastern Getic Sub-Unit with Lower Jurassic continental and marine sediments, which are followed in both sub-units by carbonate platform limestones (type Stramberk); (4) the Infra (Sub)-Getic Unit - with relatively deep water Liassic and Dogger sediments (the Dogger of type "black shales with Bossitra alpine") and Middle Callovian-Tithonian of type "ammonitico rosso"; (5) the Danubian Unit - with shallow water Liassic, Dogger and Malm (Miroc-Vrska Cuka Zone, deep water Dogger and Malm (Donjomilanovacko-Novokoritska Zone).

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Journal articles on the topic 'Callovian'

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