Faunal Dynamics Across the Silurian—Devonian Positive Isotope Excursions (δ¹³C, δ¹⁸O) in Podolia, Ukraine: Comparative Analysis of the Ireviken and Klonk Events

Abstract

Two global isotopic events, the early Sheinwoodian (early Wenlock) and that at the Silurian-Devonian transition, have been comprehensively studied in representative carbonate successions at Kytayhorod and Dnistrove, respectively, in Podolia, Ukraine, to

Regressive-transgressive cyclothem with facies record of the re-flooding window in the Late Silurian carbonate succession (Podolia, Ukraine)

“…The lower nodular limestones represent a typical shelf deposition in a subtidal zone (Nikiforova and Predtechensky 1968;Predtechensky et al 1983;Skompski et al 2006;Racki et al 2012). A low-diversity brachiopod association (resembling that reported from the Tofta Beds on Gotland, ascribed by Watkins (1992) to Silurian back-reef settings), the common occurrence of leperditid ostracods (see Vannier et al 2001), the abundance of gastropods and the dark colour of the sediments, all suggest some isolation of the sedimentary environment, with a rich input of clay material.…”

“…2. Simplified stratigraphical scheme of the Podolian Ludlow; lithostratigraphy and chronostratigrapical correlation according to Tsegelnjuk et al 1983;Drygant 1983;Koren' et al 1989;Racki et al 2012; cyclothem interpretation after Predtechensky et al 1983. Stratigraphic position of the studied sections indicated by shadow bar pected to be similar to that in clastic rocks, or in weathered profiles developed on magmatic rocks.…”

Recent studies on the Silurian of the western part of Ukraine

“…A review of the stratigraphical changes has been presented in detail i.a. by Abushik et al (1985), and in more recent papers by ), Voychyshyn (2011, Racki et al (2012) and Szaniawski and Drygant (2014). Most of sedimentological, palaeoecological and geochemical investigations, inspired usually by prof. Szaniawski from the Institute of Palaeobiology of the Polish Academy of Sciences, and carried out in the beginning of the 21st century, were focused on the short intervals corresponding to global isotopic events.…”

“…The situation changed after the foundation of the Ukrainian state in 1991, and a number of Polish researchers, in collaboration with their Ukrainian partners, began new investigations (e.g. Racki et al 2012;Środoń et al 2013;Szaniawski and Drygant 2014). The team from the University of Warsaw (authors of the present paper) began their work on the upper Silurian of Podolia in 2005, with extensive help from Prof. Danyło Drygant from the State Museum of Natural History in Lviv, National Academy of Sciences of Ukraine, who introduced us to the topic and showed us the crucial localities.…”

The Silurian of south-western margin of the East European Platform (Ukraine, Moldova and Romania): lithofacies and palaeoenvironments

“…Based on ob served tem poral changes in li thol ogy and cono dont fau nas in the car bon ate plat form rocks of Gotland, three main events -the Early Si lu rian Ireviken Event, the Mid dle Si lu rian Mulde Event, and the Late Silu rian Lau Event -have been iden ti fied (Jeppsson, 1990) with regard to biodiversity chan ges and re la tion to car bon and ox y gen sta ble iso tope evo lu tion and sea level change. For the sed i mentary suc ces sion of Podillya, Ukraine, tem po ral chan ges in isotope com po si tion (d 13 C, d 18 O) and fau nas have been es tab lished (Racki et al, 2012), which are re lated to the re gional car bon ate cri sis and cool ing ep i sodes, cor re spond ing to the Ireviken and Klonk events.…”