Larger foraminiferal and coralline algal facies in an Upper Eocene storm-influenced, shallow-water carbonate platform (Colli Berici, north-eastern Italy)

The occurrence of the channel structures in orthophragminid rudstones and in the coralline crustose pavement appears to be unique in Upper Eocene carbonate ramp depositional systems. During the erosive events associated with the return currents, these shallow-water carbonates were unlithified or only weakly lithified and were, therefore, easily transported into deeper water ramp settings. The model suggests that the significant changes of the middle-ramp benthic communities with depth could have formed, at least in part, by offshore return currents, which played an important role in both controlling substrates and in supplying nutrients.