A proposal for the subdivision of tertiary time in New Zealand

It is suggested that homotaxial biostratigraphic units are an unsuitable basis for the definition of a New Zealand Tertiary geological time scale. Three other possible ways of setting up a time scale are discussed, and it is concluded that stratigraphic marker pegs offer the best basis for a rigorously defined time scale. In order to avoid the disadvantages of a hierarchical system of naming it is further suggested that the primary names in a time scale be attached to the pegs, and not to the intervals between them. Possible objections to the use of named marker pegs as the basis for a time scale are discussed in some detail. An appendix contains points for further discussion, and some specific recommendations on the implementation of a stratigraphic marker peg scheme for New Zealand Tertiary events.