Foraminiferal sequence eco-biostratigraphy of the Middle-Early Late Miocene, Potamos section from Gavdos Island, Greece

Extremly well preserved fossil floras, evaluated by plant taxonomy and leaf physiognomy, from the Potamos Section, Gavdos Island, Greece are well dated to the Middle- and early Late-Miocene by mid- to outer-shelf assemblages of planktonic and benthonic foraminifera. The essentially parallel trends in the dominating benthic groups - epifaunal Cibicides and infaunal Bolivina and Uvigerina allow us to identify at least two nutrient-rich events. These two events are characterized by low specific diversity in the plankton and a high abundance of the planktonic species G. bulloides. Among the benthos, infaunal species increase in abundance. Planktonic upwelling indicator G. bulloides and many delicate Bolivina spp., together with a higher planktonic ratio and a relatively low benthic diversity, indicate cooler, if not deeper, depositional environments. The fluctuating differences in relative abundances between inner and outer neritic taxa can be quantified as a curve, enabling the recognition of possible sequences with boundaries implied at the peaks in inner neritic forms. In some levels, collapse in P/B ratio, decrease in deep waterbenthics and increase in elphidiids, may indicate the existence of sequence boundaries.