Late Aptian palaeoclimatic turnovers and volcanism: Insights from a shallow-marine and continental succession of the Apennine carbonate platform, southern Italy

New insights into the palaeoenvironmental–palaeoclimatic significance and sedimentary dynamics of carbonate Lagerstätten: The lower Albian of Pietraroja (Southern Italy)

“…Hence, following Raspini (2012), the extremely low Mg/Ca molar ratio and high Ca 2+ concentration in Aptian-Albian seawater (Stanley, 2006;Ries, 2010) could have exerted a decisive role in the precipitation of almost pure calcite during the formation of the Middle Plattenkalk horizon and, possibly, in the entire studied section. A similar, very low-Mg calcite in the upper Aptian, Frenelopsis-rich palaeosol of Il Campo Plattenkalk, which was deposited during a cold snap under arid hydroclimates (Graziano et al, 2016), lends further support to this view.…”

“…The eoalpine ApCP underwent multiple longterm exposures in the Aptian-Turonian p.p. with local development of bauxite and lacustrine or saltmarsh to evaporite deposits, depending on major shifts in hydroclimatic conditions (Mindszenty et al, 1995;Carannante et al, 2007;Simone et al, 2012;Graziano & Raspini, 2015;Graziano et al, 2016;Bartiromo et al, 2019). Distinct fossil Lagerst€ atten, 0.5 to 1.5 m thick on average, were therefore formed as major stratigraphic key markers during the longest sea-level lowstands in the Aptian-Cenomanian (Bravi et al, 2004;Bartiromo et al, 2012Bartiromo et al, , 2019Graziano et al, 2016).…”

“…with local development of bauxite and lacustrine or saltmarsh to evaporite deposits, depending on major shifts in hydroclimatic conditions (Mindszenty et al, 1995;Carannante et al, 2007;Simone et al, 2012;Graziano & Raspini, 2015;Graziano et al, 2016;Bartiromo et al, 2019). Distinct fossil Lagerst€ atten, 0.5 to 1.5 m thick on average, were therefore formed as major stratigraphic key markers during the longest sea-level lowstands in the Aptian-Cenomanian (Bravi et al, 2004;Bartiromo et al, 2012Bartiromo et al, , 2019Graziano et al, 2016). Figure 2 reports the resulting continental and paralic fossiliferous Lagerst€ atten in the upper Aptian-lower Albian of the ApCP in the south-east Matese Mountains which is being increasingly referred to as a crucial area for understanding the high-frequency mid-Cretaceous palaeoclimatic dynamics in a supra-regional perspective (Graziano et al, 2016).…”

“…Furthermore, windblown pyroclastic material may have favoured the growth and preservation of diversified plants and abundant organic matter at Pietraroja (cf. Haworth & McElwain, 2008;Longman et al, 2019), as in the case of the subaerially exposed coastal areas of the middle Cretaceous ApCP (Bartiromo et al, 2012(Bartiromo et al, , 2019Graziano et al, 2016).…”

“…Oborn, 1960). In situ alteration of the frequent tephras from the iron-depleted, arc-trench volcanism in the Dinaridic-Carpatho-Balkan region (Graziano et al, 2016; Carbonates and non-carbonate grains/precipitates section) may have provided an additional, though limited, source of biologically available iron at Pietraroja. This set of environmental features underlay the ecological climax for proliferation of the diversified terrestrial vertebrates and preservation of their fossil remains (Fig.…”