Fossil plant associations are best named by traditional phytosociological methods from genera or species prominent in a reference collection. The named association then has some stability during later palaeoecological interpretation and threedimensional mapping in sedimentary basins. Biostrati-graphic zones are best established from successions of events in similar associations within a specified area. Such events may not have occurred in other types of association, nor have been contemporaneous in separate areas. These events are most effectively correlated when the likely environment and ecology of the associations are also considered.