Quantitative Stratigraphy, Splining and Geologic Time Scales - Geomathematics: Theoretical Foundations, Applications and Future Developments - page 352

Fig. 9.35 The International Geologic Timescale (GTS2012) (Source: Gradstein et al. 2012 ,Fig.1.2)
9.5.1 Timescale History
The very first numerical time scales were constructed between 1911 and 1960 by
Arthur Holmes who remarked: “To place all the scattered pages of earth history in
their proper chronological order is by no means an easy task” (Holmes 1965 ,
p. 148). In 1911 Holmes examined the decay of uranium to lead in seventeen