Abstract

The accurate measurement of geological time is important for purposes of correlation and the understanding of geological history, facies distribution, and the timing of tectonic events. For this purpose, radioactive dating and paleontology are the main tools available.

In oil exploration, paleontology is the primary tool used. Because of strong ecological control, benthonic organisms cannot be used for world wide correlations but can be used to give broad ages and possible local correlations; benthonic organisms are very valuable in the recognition of environments of deposition. World wide correlations must be based on planktonic organisms which, in spite of their limitations, are free of restrictions of benthonic organisms and provide the best basis for subdividing geological time in marine sedimentary sequences and world wide correlation.

The absence of guide lines in the codes of stratigraphic nomenclature in the recognition of time units and the definitions of the various time units has led and continues to lead to confusion. Paleontologists must recognise the limitations of their various fossil groups and use only planktonic organisms for age dating, world wide correlations, and the definitions of the various time units.

Problems in age determinations and correlations were faced by the early paleontologists in Indonesia and Papua New Guinea because of the absence of the use of Tertiary planktonic foraminifera and nannoplankton. Problems still exist because of the continued absence of established guide lines and the adherence to the European type sections.