The Berriasian Tirnovella Occitanica Zone in the Feodosia Area (Eastern Crimea)
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See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/335673485 The Berriasian Tirnovella occitanica Zone in the Feodosia Area (Eastern Crimea) Article in Moscow University Geology Bulletin · March 2019 DOI: 10.3103/S0145875219020029 CITATIONS READS 0 71 4 authors: Baraboshkin Evgeny Arkadiev Vladimir Lomonosov Moscow State University Saint Petersburg State University 174 PUBLICATIONS 1,730 CITATIONS 196 PUBLICATIONS 660 CITATIONS SEE PROFILE SEE PROFILE Andrey Yu. Guzhikov Evgeny E. Baraboshkin Saratov State University Skolkovo Institute of Science and Technology 104 PUBLICATIONS 365 CITATIONS 33 PUBLICATIONS 39 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: Paleontological museum collections View project Bazhenovo Formation of Western Siberia View project All content following this page was uploaded by Arkadiev Vladimir on 10 September 2019. The user has requested enhancement of the downloaded file. ISSN 0145-8752, Moscow University Geology Bulletin, 2019, Vol. 74, No. 2, pp. 143–153. © Allerton Press, Inc., 2019. Russian Text © The Author(s), 2019, published in Vestnik Moskovskogo Universiteta, Seriya 4: Geologiya, 2019, No. 1, pp. 26–37. The Berriasian Tirnovella occitanica Zone in the Feodosia Area (Eastern Crimea) E. Yu. Baraboshkina, *, V. V. Arkadievb, **, A. Yu. Guzhikovc, ***, and E. E. Baraboshkind, **** aDepartment of Geology, Moscow State University, Moscow, 119234 Russia bInstitute of Earth Sciences, St. Petersburg State University, St. Petersburg, 199034 Russia cDepartment of Geology, Saratov State University, Saratov, 410012 Russia dIntegrated Center for Hydrocarbon Recovery, Skolkovo Institute of Science and Technology, Moscow, 1212015 Russia *e-mail: [email protected] **e-mail: [email protected] ***e-mail: [email protected] ****e-mail: [email protected] Received May 21, 2018; revised May 21, 2018; accepted May 22, 2018 Abstract—The occurrence of the Tirnovella occitanica Ammonite Zone in the Berriasian section of Feodosia was confirmed here for the first time. The results of sedimentological, bio-, and magnetostratigraphic study of this interval are discussed. Keywords: ammonites, Tirnovella occitanica, ichnofossils, Berriasian, biostratigraphy, magnetostratigraphy, petromagnetism, sedimentology, Feodosia, Eastern Crimea DOI: 10.3103/S0145875219020029 INTRODUCTION fore well exposed. The rocks are highly dislocated: the dip azimuth varies from 42° to 172°, the dip angle is In 1893 O.F. Retowski (Retowski, 1893) described from 10° to 50°. Ten units with an observed thickness numerous specimens of Hoplites occitanicus ammonites in the environs of Feodosia. However, the exact locality, of approximately 115 m (from bottom to top) are dis- as well as the stratigraphic position of this find, were tinguished in the section. All rocks are completely bio- unknown. T. N. Bogdanova, E.D. Kalacheva, and turbated and the primary structures are rarely pre- served. I.I. Sei [1999] described the genus Tirnovella occitanica (Pictet) and substantiated the occurrence of the Berri- Unit 1. Irregular alternation of completely biotur- asian Occitanica Zone in the Feodosia section based bated pale gray calcareous clays (up to 0.2–1.6 m; on the revision of Retowski’s collection; however, all Figs. 2, 3) and thick (up to 0.9 m) mudstone interbeds attempts to find Tirnovella occitanica in Eastern Crimea with aleuritic-size quartz admixture and tiny plant were unsuccessful. detritus (Fig. 2, 4). Mudstones are broken by numer- In the summer of 2016, E.Yu. Baraboshkin, ous thin cracks filled with block calcite. The unit con- E.E. Baraboshkin, T.A. Kulashova (Moscow State tains ichnofossils Alcyonidiopsis bavaricus Uchman University) and A.Yu. Guzhikov studied the section (figs. 2, 6), Chondrites isp., Planolites isp., Rhizocoral- of the Sultanovskaya Formation in the Zavodskaya lium commune Schmid (Fig. 2, 5); Thalassinoides sue- Balka quarry on the outskirts of the town of Feodosia vicus and partially pyritized wood residues. Ammo- (Figs. 1A, 1B). As a result, previously unknown strati- nites Euphylloceras sp., Ptychophylloceras sp. and rare graphic levels of the Sultanovskaya Formation charac- bivalves Nucula sp., Modiola sp. were found in the terized by ammonites were identified. Below, the lower part of the unit, and Tirnovella occitanica (Pic- description of the section along with its sedimentolog- tet) was found at the top of the thick mudstone bed ical (E.Yu. Baraboshkin and E.E. Baraboshkin) and (Fig. 3, 4–8), Protetragonites sp. and Berriasella priva- magnetostratigraphic (A.Yu. Guzhikov) interpreta- sensis (Pictet). The visible thickness is 5.2 m. tions, as well as the biostratigraphic substantiation of Unit 2. The frequent alternation of light gray bio- the Tirnovella occitanica Zone and its description turbated calcareous clays (0.4–1.4 m) and thin mud- (V.V. Arkadiev) are given. stone interbeds (0.1–0.3 m), similar to those described Structure of the section. The section is located on above. At the top are small pyrite nodules. The unit the southern side of the operating quarry and is there- contains abundant ichnofossils Chondrites isp., Plano- 143 144 BARABOSHKIN et al. (b) Azov Sea Kerch m STAGE ZONE SUBZONE UNIT POLA- RITY Republic of Crimea 100 Val. 10 12/52 Feodosia 70 Simferopol B. callisto Sudak Sevastopol Feodosia Alushta Nasypnoe Black Yalta Black Sea Sea 60 Zavodskaya Balka quarry (a) 2.6 km Riasanites crassicostatum Sample Kr16-11/3 Sample Kr16-12/28 -12/28 Amphibole 1% Pyrite 1% ms mica– % % smectite 2% 3 2 50 % e e 2% 9 t t i iti % a r t 0 c Zeolite 1% e c 1 i d e i a m c Siderite 3% Siderite S mectm i o r S m d o y r ms mica– Chlorite 3% d Zeolite 1% HHydromic y smectite 6% HHydromica 10% Chlorite 2% Calcite 58% Quartz 21% Calcite 42% Fauriella boissieriFauriella Plagioclase 6% Plagioc Quartz 29% 40 lase 3% lase (c) BERRIASIAN 4 123 67 30 euthymi Neocosmoceras 5 (d) 89 K, Jn, Jrs, K/Jrs, –5 –4 D, deg I, deg 10 , SI units 10–3 A/m Q A/m 10 m/A 0 100 200 300 –50 0 50 10 20 40 60 0 10 20 0 0.5 1.0 1.5 0 3 6 0 2 4 6 Paleomagnetic Paleomagnetic samples 3114/16 20 3114/15 3114/14 3114/13 3092/12 3092/11 3092/9, 10 3092/8 3092/7 3092/6 10 3114/5A 3092/5 3092/4 3114/3B Tirnovella occitanica Tirnovella 3114/3A 3092/3 3114/2C 123456789 3114/2B -11/5 3114/2A -11/3 3092/2 0 3092/1 Fig. 1. The Berriasian section in the Zavodskaya Balka section (Feodosia): а, locality scheme; b, structure of the section; c, composition of the clayey fraction of samples of Kr16-11/3 (Tirnovella occitanica Zone) and Kr16-11/3 (Fauriella boissieri Zone); d, magnetostratigraphic section of Tirnovella occitanica Zone: 1, grainstones, 2, mudstones, 3, calcareous clays, 4, Tirn- ovella occitanica, 5, finds of other ammonites, 6, pyrite nodules, 7, numbers of samples for X-ray phase analysis, 8–9, geomag- netic polarity: 8, normal (а, reliable; b, proposed), 9, reverse (a, reliable; b, proposed). MOSCOW UNIVERSITY GEOLOGY BULLETIN Vol. 74 No. 2 2019 THE BERRIASIAN TIRNOVELLA OCCITANICA ZONE 145 QrQr ExEx ShSh F Q A ExEx Q P A 1 ShSh 500500 m 2 C B Q 500500 m 500500 m 3 4 5675 6 7 Fig. 2. 1, a view of the southwestern side of the quarry, arrow shows the bed with Tirnovella occitanica; thin-sections of represen- tative rocks: 2, thin section Kr16-12, grain–rudstone of mixed composition, parallel nicols; 3, thin section Kr16-11-3, calcareous clay, parallel nicols; 4, thin section Kr16-11-5, clayey mudstone, parallel nicols; letter designations: А, algae remains; В, biotur- bation; С, small phytodetritus; Ex, extraclasts; Р, peloids; Q, quartz; Qr, quartzite; Sh, schist; some ichnofossils: 5, Rhizocoral- lium commune Schmid, 1876 and Chondrites isp., Sample 127/11, 6, Alcyonidiopsis bavaricus Uchman, 1999, Sample 127/7; 7, Thalassinoides isp., Sample 127/13. Collections and images of E.Yu. Baraboshkin and E.E. Baraboshkin, 2015–2016. Scale bar, 1 cm. The collection is stored in the Earth Science Museum (MSU), no. 127. lites isp., Thalassinoides isp. In the upper part of the Unit 3. Dark gray bioturbated calcareous clays unit is a hiatus of undefined scale. The proposed (2.5–3 m) with small pyrite nodules at the top and thickness is 24–25 m. bottom of the unit. Clays alternate with rare interbeds MOSCOW UNIVERSITY GEOLOGY BULLETIN Vol. 74 No. 2 2019 146 BARABOSHKIN et al. 12a2b3 5a 5b 4b 4a 1 cm 6b 6a 7a 7b 8 Fig. 3. Berriasella privasensis (Pictet): 1, Sample no. 6/130, lateral view; 2, Sample no. 7/130: 2а, lateral view, 2b, ventral view; 3, Sample no. 8/130: 3а, lateral view, 3b, ventral view; Tirnovella occitanica (Pictet): 4, Sample no. 2/130: 4а, lateral view, 4b, ven- tral view; 5, Sample no. 3/130: 5а, lateral view, 5b, ventral view; 6, Sample no. 5/130: 6а, lateral view, 6b, ventral view; 7, Sample no. 1/130: 7а, lateral view, 7b, ventral view; 8, Sample no. 4/130, lateral view; all samples are from Eastern Crimea, Feodosia, Zavodskaya Balka quarry, Berriasian, occitanica zone. Magnification, 1×. MOSCOW UNIVERSITY GEOLOGY BULLETIN Vol. 74 No. 2 2019 THE BERRIASIAN TIRNOVELLA OCCITANICA ZONE 147 of light gray mudstones (0.25–0.3 m) and contain the cyclic change in the carbonate content. The ichno- same ichnofossil assemblage, as well as pyritized wood complex described in the section indicates that it residues. The thickness is 8 m. belongs the Cruziana ichnofacies of the open shelf Unit 4. Dark gray bioturbated calcareous clays with (Baraboshkin et al., 2016) and the predominance of var- small pyrite nodules at the top and bottom of the unit. ious “worms” (sipunculidus, polychaetes, etc.) among Ichnofossils such as Chondrites isp., Planolites isp., the macro- and meiobenthos of crustaceans.