Introduction.The study of catastrophic events that affected past marine ecosystems provides us the unique opportunity to establish models which can be applied to ongoing environmental changes and to understand future ...Introduction.The study of catastrophic events that affected past marine ecosystems provides us the unique opportunity to establish models which can be applied to ongoing environmental changes and to understand future evolution of the biotas.The growing interest of the society for the ongoing and potential future environmental changes attests for the value represented by the analysis of past climatic changes.In the case of the Toarcian Oceanic Anoxic Event(T-OAE,Early Jurassic;~182 Ma),a dramatic change of marine ecosystems related to massive extinction has been documented in several areas around the world.The Pliensbachian–Toarcian transition and the T-OAE are two global episodes recording worldwide palaeoenvironmental perturbations(Jenkyns,1988;Jenkyns and Clayton,1997;Hesselbo et al.,2007).The end of the Pliensbachian regression is followed by a transgression occurring in the Early Toarcian(Haq et al.,1987;de Graciansky et al.,1999).This transgression was also coeval with a widespread deposition of black shales(Jenkyns,1988),a global warming(Garcia Joral et al.,2011;Korte and Hesselbo,2011;Suan et al.,2011),and perturbations of the carbon cycle indicated by a negative carbon isotopic excursion(CIE)documented in both marine and terrestrial material(Jenkyns and Clayton,1986;Schouten et al.,2000;Hesselbo et al.,2007;Al-Suwaidi et al.,2010;Caruthers et al.,2011;Izumi et al.,2012;Reolid,2014).展开更多
基金This is a contribution of the IGCP-655 project of the IUGS and UNESCO.
文摘Introduction.The study of catastrophic events that affected past marine ecosystems provides us the unique opportunity to establish models which can be applied to ongoing environmental changes and to understand future evolution of the biotas.The growing interest of the society for the ongoing and potential future environmental changes attests for the value represented by the analysis of past climatic changes.In the case of the Toarcian Oceanic Anoxic Event(T-OAE,Early Jurassic;~182 Ma),a dramatic change of marine ecosystems related to massive extinction has been documented in several areas around the world.The Pliensbachian–Toarcian transition and the T-OAE are two global episodes recording worldwide palaeoenvironmental perturbations(Jenkyns,1988;Jenkyns and Clayton,1997;Hesselbo et al.,2007).The end of the Pliensbachian regression is followed by a transgression occurring in the Early Toarcian(Haq et al.,1987;de Graciansky et al.,1999).This transgression was also coeval with a widespread deposition of black shales(Jenkyns,1988),a global warming(Garcia Joral et al.,2011;Korte and Hesselbo,2011;Suan et al.,2011),and perturbations of the carbon cycle indicated by a negative carbon isotopic excursion(CIE)documented in both marine and terrestrial material(Jenkyns and Clayton,1986;Schouten et al.,2000;Hesselbo et al.,2007;Al-Suwaidi et al.,2010;Caruthers et al.,2011;Izumi et al.,2012;Reolid,2014).
