A record of Late Ordovician to Silurian oceanographic events on the margin of Baltica based on new carbon isotope data, elemental geochemistry, and biostratigraphy from two boreholes in central Poland

Biotic, geochemical and environmental changes through the early Sheinwoodian (Wenlock, Silurian) carbon isotope excursion (ESCIE), Buttington Quarry, Wales

“…Since then the ESCIE has been recognised for the first time in the Barrandian area by Frýda et al (2015) and there have been studies integrating geochemical, sedimentological and fossil data through this interval in Poland (e.g. Racki et al, 2012;Smolarek et al, 2017;Sullivan et al, 2018).…”

“…Integrated biostratigraphical studies of sections in Estonia and Latvia (Loydell et al, 1998(Loydell et al, , 2003 place this level within the murchisoni Biozone, with Männik (2007) suggesting that it would be at a high level within this graptolite biozone. Most recently, Sullivan et al (2018)…”

Early Silurian δ13Corg excursions in the foreland basin of Baltica, both familiar and surprising

“…The discovery of SOCIE is a surprise considering that compilations of δ 13 C data for the Silurian (e.g. Cramer et al, 2011;Melchin et al, 2012;Sullivan et al, 2018) indicate that the late Llandovery is characterized by a single negative excursion close to the base of the Telychian, the Rumba low (see above), and a minor positive excursion, the Valgu excursion (Munnecke and Männick, 2009), in the early-mid Telychian. The remainder of the Telychian is shown as isotopically bland.…”

“…However, since all of the main Silurian excursions discerned so far can be recognized in both δ 13 Ccarb and δ 13 Corg records (e.g. Cramer et al, 2011;Melchin and Holmden, 2006;Sullivan et al, 2018), an attempt to identify the SOCIE in published δ 13 Ccarb curves is justifiable. In the four δ 13 Ccarb records discussed above (the Ventspils D-3 core from Latvia and the Ruhnu (500), and Viki core from Estonia), the SOCIE is not recognized in the shallowest setting (in the Viki core; Kaljo et al, 1998;Kaljo et al, 2003).…”

“…Since these reviews, the excursion has been identified also in the Barrandian area, Czech Republic, by Frýda et al (2015) and in Poland (e.g. Racki et al, 2012;Smolarek et al, 2017;Sullivan et al, 2018), and a detailed study of the early stages of the excursion has been undertaken on the Buttington section, Wales (Loydell and Large, 2019). In sections with good biostratigraphical control, the ESCIE (with amplitudes varying from 2-4‰) can be seen to begin high in the Cyrtograptus murchisoni Biozone (Loydell and Frýda, 2007, fig.…”