Holocene sea-level oscillations and environmental changes on the Eastern Black Sea shelf Elena V. Ivanova a, ⁎ , Ivar O. Murdmaa a , Andrey L. Chepalyga b , Thomas M. Cronin c , Ivan V. Pasechnik d,1 , Oleg V. Levchenko a , Stephen S. Howe e , Anastasiya V. Manushkina d , Elena A. Platonova d a Shirshov Institute of Oceanology, Russian Academy of Sciences, 36 Nakhimovsky Prosp., 117997, Moscow, Russia b Institute of Geography, Russian Academy of Sciences, 29 Staromonetny Per., 119017, Moscow, Russia c 926A National Center US Geological Survey, Reston, Va. 20191, USA d Geology Department, Lomonosov Moscow State University, Vorobyevy Gory, 119992, Moscow, Russia e Department of Earth and Atmospheric Sciences, ES-351, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY, USA Received 3 November 2005; received in revised form 15 September 2006; accepted 26 September 2006 Abstract A multi-proxy study of four sediment cores from the Eastern (Caucasian) Black Sea shelf revealed five transgressive–regressive cycles overprinted on the general trend of glacioeustatic sea-level rise during the last 11,000 14 C yr. These cycles are well represented in micro-and macrofossil assemblages, sedimentation rates, and grain size variations. The oldest recovered sediments were deposited in the Neoeuxinian semi-freshwater basin (∼ 10,500–9000 14 C yr BP) and contain a Caspian-type mollusk fauna dominated by Dreissena rostriformis. Low δ 18 O and δ 13 C values are measured on this species. The first appearance of marine mollusks and ostracodes from the Mediterranean is established in this part of the Black Sea at ∼ 8200 14 C yr BP, i.e., about 1000–2000 yr later than the appearance of marine microfossils in the deeper part of the sea. The Early Holocene (Bugazian to Vityazevian) condensed section of shell and shelly mud sediments with at least two hiatuses represent a high-energy shelf-edge facies. It contains a transitional assemblage representing a mixture of Caspian and Mediterranean fauna. This pattern suggests a dual-flow regime via the Bosphorus after 8200 14 C yr BP. Caspian species disappear and oligohaline species decrease in abundance during the Vityazevian–Prekalamitian cycle. Later, during the Middle to Late Holocene, low sea-level stands are characterized by shell layers, whereas silty mud with various mollusk and ostracode assemblages rapidly accumulated during transgressions. Restricted mud accumulation, as well as benthic faunal composition and abundance, suggest high-energy and well-ventilated bottom water during low sea-level stands. A trend of 18 O enrichment in mollusk shells points to an increase in bottom-water salinity during the Vityazevian to Kalamitian transgressions (∼ 7000 to 5700 14 C yr BP) due to a more open connection with the Mediterranean, while a pronounced increase in polyhaline species abundance is established during the Kalamitian to Djemetean transgressions (∼ 6400 to 2700 14 C yr BP). However, the composition of the faunal assemblage indicates that bottom-water salinity never exceeded modern values of 18–20 psu. © 2006 Elsevier B.V. All rights reserved. Keywords: Black Sea; Transgression; Regression; Cycles; Holocene; Macro- and microfossils; Caucasian shelf; Paleoenvironments; Abrupt changes Palaeogeography, Palaeoclimatology, Palaeoecology 246 (2007) 228 – 259 www.elsevier.com/locate/palaeo ⁎ Corresponding author. Tel.: +7 495 129 2163; fax: +7 495 124 5983. E-mail address: e_v_ivanova@ocean.ru (E.V. Ivanova). 1 Present address: WesternGeco/Schlumberger, Suite 2300, 645 — 7th Avenue N.W., Calgary, AB, Canada, T2P 4G8. 0031-0182/$ - see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.palaeo.2006.09.014