Reconstructing Valanginian (Early Cretaceous) mid-latitude vegetation and climate dynamics based on spore–pollen assemblages

Astrochronology of the Valanginian–Hauterivian stages (Early Cretaceous): Chronological relationships between the Paraná–Etendeka large igneous province and the Weissert and the Faraoni events

“…The positive-shift phase is associated to increasing atmospheric pCO 2 (Morales, 2013), higher contents of kaolinite in Tethyan hemipelagic sediments (Fesneau, 2008;Duchamp-Alphonse et al, 2011), an increase in detrital and fluviatile supply (Habib, 1979;Weissert et al, 1998), humid-affinities spore-pollen assemblages (Kujau et al, 2013), higher nannofossil fluxes in pelagic environments Mattioli et al, 2014), evolution from oligotrophic to mesotrophic assemblages (Duchamp-Alphonse et al, 2014;Mattioli et al, 2014), notably characterized by the nannoconid decline (e.g. Barbarin et al, 2012), while the neritic Tethyan and Atlantic carbonate production dramatically decreases (Weissert et al, 1998;Föllmi, 2012).…”

Depositional characteristics and constraints on the mid-Valanginian demise of a carbonate platform in the intra-Tethyan domain, Circum-Rhodope Belt, northern Greece

“…Different lines of evidence have attested that the global climate became markedly humid (Frakes et al, 1992;Chumakov et al, 1995;Price et al, 1998;Hillg€ artner, 1999, Gr eselle et al, 2011Kujau et al, 2013;Morales et al, 2013) and cooler during the late Berriasian and early Valanginian with minimum temperatures recorded during the late Valanginian (Mutterlose and Kessels, 2000;Puc eat et al, 2003;Gr€ ocke et al, 2005;Kessels et al, 2006;Fig. 15.…”

Calcareous nannofossil response to the Weissert episode (Early Cretaceous): Implications for palaeoecological and palaeoceanographic reconstructions

“…The Early Cretaceous is characterised by increased spreading rates and volcanic activity that, together with modulations in the Earth's orbital parameters, triggered significant perturbations in the oceanclimate system (Larson, 1991;Larson and Erba, 1999;Herrle et al, 2003;Tejada et al, 2009;Kuroda et al, 2011;Kujau et al, 2013). At certain intervals, the sedimentary archives are marked by C-isotopic anomalies, episodic black-shale deposits, repeated platform drownings, and rapid turnovers in the marine biota (Erba, 2004;Weissert and Erba, 2004;Erba, 2006;Keller, 2008;Föllmi, 2012).…”

“…Our study focuses on the Angles section, located in the hemipelagic area of the Vocontian Basin (northwestern Tethyan margin), at a palaeolatitude of~30°N (Savostin et al, 1986). Such a mid-latitudinal setting, in proximity to the continent, is very sensitive to climate changes and thus is crucial to investigate fluctuations between arid and humid conditions that resulted in significant fluctuations in weathering regime, runoff, terrigenous/nutrient inputs and salinity conditions, that, in turn, may have impacted upon nannoplankton behaviour (Duchamp-Alphonse et al, 2011;Gréselle et al, 2011;Kujau et al, 2013;Westermann et al, 2013). Moreover, particular attention has been devoted to changes in global pCO 2 (Huang et al, 2012;Wang et al, 2014), nutrients (Föllmi, 1995;Bornemann and Mutterlose, 2008) and Ca 2+ levels (Hönisch et al, 2012).…”