Middlesex/punctata Event in the Rhenish Basin (Padberg section, Sauerland, Germany) – Geochemical clues to the early-middle Frasnian perturbation of global carbon cycle

Early-Middle Frasnian (Late Devonian) carbon isotope Event in the Timan-Pechora Basin (Chernyshev Swell, Pymvashor River section, North Cis-Urals, Russia)

“…Thus, the studied Early-Middle Frasnian interval consists of rhythmically intercalated thinly bedded limestone and shale deposited in deep water by episodic carbonate influx from the shallow-water platform induced by storms. Periodicity of the storms could be mediated by short-term climate changes accompanying the Middle Frasnian cooling (Pisarzowska et al, 2020). Increasing latitudinal temperature gradients probably provoked increasing in tropical storm frequency and vice versa.…”

“…The hypoxic Middlesex Event coincides with the start of a δ 13 C positive excursion in the latest Palmatolepis transitans Zone preceding a prominent drop in δ 13 C values near the Palmatolepis punctata-Early Palmatolepis hassi boundary (Ma et al, 2008;Pisarzowska et al, 2006Pisarzowska et al, , 2020Pisarzowska and Racki, 2012;Yans et al, 2007). Significant variations in the δ 13 C values in the latest transitans-punctata time interval are known as the transitans-punctata isotope Event or Early-Middle Frasnian isotopic perturbation (Pisarzowska et al, 2020;Racki et al, 2008;Yans et al, 2007), which is distinguished in distant disparate sedimentary basins throughout the world and considered to be a reliable chemostratigraphic marker of the Early-Middle Frasnian boundary (Bai et al, 1994;Baliński, 2006;Ma et al, 2008;Pisarzowska et al, 2006Pisarzowska et al, , 2020Yans et al, 2007). Detailed study of the event structure revealed a four-step positive-to-negative excursion pattern (Ma et al, 2008;Racki et al, 2008;Pisarzowska et al, 2006Pisarzowska et al, , 2020.…”

“…The stratigraphic level near the Early-Middle Frasnian boundary, known as the Middlesex Event (Becker et al, 1993;Ma et al, 2006;Pisarzowska et al, 2020), is attributed to the Late Devonian global transgression equivalent to the initial phase of cycle IIc (Johnson et al, 1985). Tectonic formation of deep intracratonic basins in the Cis-Uralian region occurred in the Middle Frasnian as well.…”

“…Significant variations in the δ 13 C values in the latest transitans-punctata time interval are known as the transitans-punctata isotope Event or Early-Middle Frasnian isotopic perturbation (Pisarzowska et al, 2020;Racki et al, 2008;Yans et al, 2007), which is distinguished in distant disparate sedimentary basins throughout the world and considered to be a reliable chemostratigraphic marker of the Early-Middle Frasnian boundary (Bai et al, 1994;Baliński, 2006;Ma et al, 2008;Pisarzowska et al, 2006Pisarzowska et al, , 2020Yans et al, 2007). Detailed study of the event structure revealed a four-step positive-to-negative excursion pattern (Ma et al, 2008;Racki et al, 2008;Pisarzowska et al, 2006Pisarzowska et al, , 2020. Manifestations of the transitanspunctata isotope Event have been well studied in West and Central Europe, South China, and North America (Bai et al, 1994;Baliński, 2006;Lash, 2019;Morrow et al, 2009;Pisarzowska et al, 2006Pisarzowska et al, , 2020Yans et al, 2007).…”

“…Detailed study of the event structure revealed a four-step positive-to-negative excursion pattern (Ma et al, 2008;Racki et al, 2008;Pisarzowska et al, 2006Pisarzowska et al, , 2020. Manifestations of the transitanspunctata isotope Event have been well studied in West and Central Europe, South China, and North America (Bai et al, 1994;Baliński, 2006;Lash, 2019;Morrow et al, 2009;Pisarzowska et al, 2006Pisarzowska et al, , 2020Yans et al, 2007). However, much less is known of this event in East Europe (Soboleva et al, 2018;Zhuravlev et al, 2006).…”