DINOFLAGELLATE CYSTS, PALEOPRODUCTIVITY AND UPWELLING SYSTEMS - A LATE CRETACEOUS EXAMPLE FROM ISRAEL

Diverse assemblages of dinoflagellate cysts occur in Coniacian-Maastrichtian sedimentary sequences in Israel, which represent the inner (shallower) and outer (deeper, seaward) belt of a Late Cretaceous upwelling system along the margin of the southern Tethys. The assemblages are composed mainly of peridinioid (P) and gonyaulacoid (G) cysts in varying concentrations. It is suggested that the observed fluctuations in the numerical peridinioid/gonyaulacoid (P/G) cyst ratio reflect mainly changes in upwelling intensity and productivity in the studied area: high P/G values represent a higher productivity and vice versa. The P/G curve indicates a generally high productivity during the Campanian, followed by a decrease during the Maastrichtian. The inner part of the upwelling region is characterized by higher P/G values, representing a higher productivity. The similarity between the P/G ratio curve and the foraminiferal-based paleoproductivity curve from the same sections supports the utility of the P/G ratio as a reliable productivity indicator, applied here for the first time to Upper Cretaceous sediments.