Benthic foraminiferal assemblages from the St. Peter's Pool section (south eastern Malta Island)

Preliminary paleoecological data on benthic foraminiferal assemblages of St. Peter's PoDI section (south-eastern Malta Island), are presented. The upper Burdigalian- Langhian St. Peter's PoDI section (MMi4a-MMi4b planktonic foraminiferal biozonal scheme of Di Stefano et al., 2008 emended by Iaccarino et al., 2011) that outcrops at Delimara Peninsula, belongs to the Upper Globigerina Limestone, the youngest member of the Globigerina Limestone formation. The sedimentary record consists of cyclic alternations of calcareous mari, marly limestone and bioturbated hardened limestone. Benthic assemblages are mainly represented by species typical of an upper-middle bathyal environment. Throughout the section the most abundant species are Siphonina reticulata, Cibicidoides dutemplei-subhaidingerii, together with Uvigerina peregrina, Bulimina costata and Bolivina spathulata. The opposite trend of S. reticulata and U. peregrina together with the distribution patterns of the other significant species point out three mai n intervals along the section. The ecological/paleoecological meaning of tbe main benthic species is reported in Iiterature (Kouwenhoven and Van der Zwaan, 2006, among others). lnterval A (O - 6 m): increasing trend of the oxic species S. reticulataup to 20% and occurrence of the high productivity species U. peregrina (average value 11%), B. costata (average value < 1%) and of the dysoxic species B. spathulata (average value 4%). This interval suggests a well oxygenated bottom environment. Interval B (6 - 12 m): increasing trend of U. peregrina and B. costata with a peak respectively of 27% and 13% at 12 m; decreasing trend of S. l'eticI/lata with its minimum value of 2% at 12 m. This interval reveals high productivity and high organic matter content at the sea fioor as consequence. lnterval C (12 - 30 m): increasing trend of S. reticulata and of the oxic species C. dutempleisubhaidingerii; generai decreasing trend of U. peregrina, which shows a peak of 17% at 24 m, and of B. costata. This interval allows to hypothesize a relatively well oxygenated bottom environment with an episode of increased productivity at 24 m.