Palynofacies of the Lower Cretaceous Pietraroja Lagerstätte (Campanian Apennines, southern Italy): Tool to unravel the depositional environment

The early Albian Pietraroja Lagerstätte, famous for its exceptional fossil preservation and the finding of the theropod dinosaur Scipionyx samniticus (Dal Sasso and Signore, 1998), revealed well-preserved plant remains in the so-called Plattenkalk shedding light on the plant diversity of the Apenninic Carbonate Platform during the Early Cretaceous. The described macrofloral assemblage, its preservation and plant taphonomy support a low-energy, shallow-water environment with parautochthonous and allochthonous elements being preserved (Bartiromo, 2013). However, the depositional setting of these laminated, bituminous limestones is still controversial. Previous interpretations reach from a shallow intra-platform basin, high-energy marginal marine platform, restricted lagoon, to submarine channels. Here, we present palynofacies data from the Pietraroja Plattenkalk aiming to unravel the depositional setting of these early Albian deposits: The high percentage of amorphous organic matter (AOM) and well-preserved cuticles, as well as large phytoclasts and prasinophytes support a lagoonal environment. Stratigraphic variations in the sedimentary organic matter content may point to changes in fluvial sources, salinity, and high-frequency sea-level fluctuations. Ongoing studies target an integrated sedimentological and palynological-palaeobotanical approach to unravel the depositional history of the Albian Plattenkalk of the Pietraroja Lagerstätte.