Late Ludfordian Correlations and the Lau Event

A long-lasting steady period of isotopically heavy carbon in the late Silurian ocean: evolution of the δ13 record and its significance for an integrated δ13, graptolite and conodont stratigraphy

“…Besides the Barrandian area, this general shape of the mid-Ludfordian carbon isotope excursion has also been recorded in different areas of Baltica (Gotland, Poland;Jeppsson et al 2007Jeppsson et al , 2012Kozłowski & Munnecke 2010;Kozłowski & Sobień 2012), Australia (Broken River Province; Jeppsson et al 2007Jeppsson et al , 2012 and Laurentia (Nevada - Saltzman 2001, Frýda et al, unpublished data). For the reasons mentioned above, the chemostratigraphic zonation of the mid-Ludfordian carbon isotope excursion established herein could also be used for the latter areas and thus also for intercontinental correlations.…”

“…This also holds true for both graptolite and conodont zonations at the level of the mid-Ludfordian CIE. The conodont zonation of the latter interval was recently discussed in detail (see Corradini & Barrick 2009, Corriga & Corradini 2009, Slavík et al 2010, Slavík & Carls 2012, Jeppsson et al 2012.…”

“…On the other hand, the latter prominent geochemical event was preceded only by a moderate faunal crisis referred to as the LAU conodont bioevent (Jeppsson 1987), Kozlowskii graptolite bioevent (Urbanek 1993), and Pentamerid bioevent (Talent et al 1993). The midLudfordian carbon isotope excursion and the associated faunal turnover was hitherto documented from many palaeocontinents, in particular from different areas of Baltica (see Kaljo et al 1997, Calner 2008, Eriksson et al 2009, Jeppsson et al 2012and Kozłowski & Sobień 2012 for review), Australia (Talent et al 1993, Andrew et al 1994, Jeppsson et al 2007, Laurentia (Barrick 2010), Perunica (Lehnert et al 2003(Lehnert et al , 2007Manda et al 2012), Avalonia (Loydell & Frýda 2011), and the Carnic Alps (Histon & Schönlaub 1999, Brett et al 2009, Histon 2012. The high magnitude of the δ 13 C values makes the mid-Ludfordian carbon isotope excursion probably the most intensively studied of all Palaeozoic geochemical events.…”

“…The published data concerning mainly shallow water environments clearly shows that the beginning of the mid-Ludfordian CIE is connected with rapid shallowing (Lehnert et al 2003(Lehnert et al , 2007Eriksson & Calner 2006;Jeppsson et al 2012). Kozłowski & Munnecke (2010) compared sequence stratigraphy analyses of Gotland and the Holy Cross Mountains and concluded that "the positive Ludlow δ 13 C excursion is connected with prolonged low-stand conditions with small, internal transgressive pulses".…”

Facies development and sequence stratigraphy of the Ludfordian (Upper Silurian) deposits in the Zbruch River Valley, Podolia, western Ukraine: local facies overprint on the δ13Ccarb record of a global stable carbon isotope excursion

“…The Ludfordian (Upper Silurian) stage was the time of the most pronounced positive stable carbon isotope excursion (CIE) in the Phanerozoic, known as the Lau excursion (Wenzel and Joachimski 1996;Bickert et al 1997;Wigforss-Lange 1999;Calner et al 2004;Martma et al 2005; Kaljo and Martma 2006;Jeppsson et al 2007;Kaljo et al 2007; Lehnert et al 2007;Eriksson and Calner 2008;Barrick et al 2010;Kozłowski and Munnecke 2010;Munnecke et al 2010;Cramer et al 2011;Loydell and Frýda 2011;Jeppsson et al 2012;Kaljo et al 2012;Kozłowski and Sobień 2012). Very good geochemical, biostratigraphical, and paleoecological documentation exists for the Lau excursion, and it is often used as a model to study positive CIEs, which are widely used as chemostratigraphic markers and as indicators of perturbations of the global carbon cycle (Jeppsson 1990;Aldridge et al 1993;Bickert et al 1997;Jeppsson and Aldridge 2000;Munnecke et al 2003;Calner 2005a;Melchin and Holmden 2006;Cramer and Saltzman 2007a, b;Fanton and Holmden 2007;Calner et al 2008;Małkowski et al 2009;Kozłowski and Sobień 2012).…”