Lectures will introduce the various microfossil groups and detail their utility as important indicators of past environments by examining the ecology of living microplankton taxa and extrapolating this to the fossil record (paleoecology, paleoceanography). The applicability of different microfossil groups in providing both relative timescales (through zonal schemes) and biostratigraphic correlation will be detailed, as will the role of certain microfossils in understanding evolutionary processes. Microplankton as agents of global environmental change will also be investigated, especially with regard to fluxes of CaCO3 and C and hence to CO2 in the atmosphere. The microfossil groups which will be studied in the above context are those which form mineralised skeletons (calcareous, siliceous, phosphatic) and the organic-walled microfossils (known as palynomorphs).