The mid-Tournaisian (Early Carboniferous) anoxic event in the Laurussian shelf basin (Poland): An integrative approach

Weak and intermittent anoxia during the mid-Tournaisian (Mississippian) anoxic event in the Montagne Noire, France

“…Meyer & Kump, 2008;Jenkyns, 2010). The mid-Tournaisian event, which occurred during the Mississippian (355 Ma), is among the least studied OAE (Siegmund et al 2002;Bábek et al 2016;Rakociński et al 2021aRakociński et al , 2022. The global transgression during the mid-Tournaisian is associated with anoxic conditions during deposition of sediments in many parts of the world (e.g.…”

“…The global transgression during the mid-Tournaisian is associated with anoxic conditions during deposition of sediments in many parts of the world (e.g. Siegmund et al 2002;Bábek et al 2016;Rakociński et al 2021aRakociński et al , 2022, and this event is also termed the Lower Alum Shale Event (LASE; see Becker, 1993a,b;Walliser, 1996;Becker et al 2016). The LASE was characterized by distinctive facies changes in deep portions of open-marine environments including the transformation from pelagic carbonate sedimentation to the deposition of organic-rich black shales and cherts/radiolarites or black to dark grey radiolarian cherts and lydites (e.g.…”

“…The LASE was characterized by distinctive facies changes in deep portions of open-marine environments including the transformation from pelagic carbonate sedimentation to the deposition of organic-rich black shales and cherts/radiolarites or black to dark grey radiolarian cherts and lydites (e.g. Siegmund et al 2002;Bábek et al 2016;Rakociński et al 2021aRakociński et al , 2022. These changes affected pelagic and benthic organisms, such as goniatites, brachiopods, gastropods, bivalves and trilobites (see e.g.…”

“…The association between the LASE and volcanic activities caused climatic changes, which increased marine productivity and simultaneously stopped carbonate production (e.g. Siegmund et al 2002;Rakociński et al 2021aRakociński et al , 2022. The LASE preceded the climatic cooling and globally marked positive carbon isotope shift in the mid-Tournaisian that is known as the mid-Tournaisian carbon isotope excursion (TICE) or Kinderhookian-Osagean δ 13 C excursion (e.g.…”

“…Buggisch et al 2008;Chen et al 2021). However, knowledge on this biotic turnover remains scant, especially relative to geochemical changes in palaeoenvironments at a supra-regional scale (see Rakociński et al 2021aRakociński et al , 2022.…”