The distinct palaeoecological record of shallow marine benthic Ostracods and Foraminifers: Insights from the Holocene of the North Adriatic

Benthic ostracods and foraminifers are extensively applied as palaeoenvironmental indicators in shallow marine successions. The record of the two benthic groups is often combined to obtain detailed insights about the coastal evolution in response to late Quaternary allogenic and autogenic factors, overlooking that the information recorded by benthic ostracods and foraminifers could be significantly different. We performed a critical comparison of the palaeoecological record provided by benthic ostracod and foraminifer assemblages from the shallow marine intervals of three cores recovered in the Po Delta (Italy), framing our data in a sequence stratigraphic perspective and applying multivariate elaborations. The modern North Adriatic reference set allowed to assess (dis-)similarities in quantitative reconstructions of significant environmental parameters between the two groups. Results demonstrate that both benthic ostracods and foraminifers efficiently discriminate transgressive (TST) and highstand (HST) systems tract, as well as distance from palaeo-river mouths, with the most relevant palaeoecological changes recorded within delta lobe-fringe deposits. The complementarity of benthic ostracods and foraminifers is evidenced: the former highlight shifts in depositional regimes in response to allogenic and autogenic factors, the latter provide information about river input fluctuations in terms of organic matter.