EARTHTIME AND THE INTERNATIONAL COMMISSION ON STRATIGRAPHY: INTEGRATING GEOCHRONOLOGY AND CHRONOSTRATIGRAPHY TO ACHIEVE EARTHRATES OBJECTIVES

The revolution in the temporal precision of geochronology enabled by the EARTHTIME program during the past decade was mirrored in many ways by the stratigraphic revolution that is currently underway within integrated bio-chemostratigraphy communities throughout the timescale. In just the same way as you cannot attain rates without dates, you also cannot attain rates without stratigraphy. Unfortunately, for much of the history of geology, the stratigraphic community and the geochronologic community have been two separate and distinct entities that too often find it difficult to communicate effectively, let alone work in direct collaboration towards a high-precision temporally calibrated geologic timescale.

The International Commission on Stratigraphy (ICS), and its embedded subcommissions on each geologic period, remains the ‘official’ timekeeper of the Geologic Time Scale (GTS). However chronostratigraphy remains the first, and often only, consideration of the ICS and the international subcommissions (at least for the Phanerozoic), which leaves temporal calibration of their decisions as a matter for someone else to worry about after the fact. As a result, those who are most intimately involved in the seemingly arcane decisions of placements of Global Boundary Stratotype Sections and Points (GSSPs) are typically not at all the same people who are involved in the numerical calibration of the GTS in part or in whole. At present, there are astonishingly few geochronologists who serve as voting members of subcommissions of the ICS.

Once upon a time, there was an ICS subcommission on geochronology. Although not embedded into period subcommissions, that arrangement at least offered expertise to the stratigraphic community and an obvious line of communications between the geochronologic and stratigraphic communities. With the precision of geochronology now typically surpassing the precision of chronostratigraphic correlation, it is time once again to consider the role of geochronology in the ICS and use EARTHRATES as a platform to enable this discussion.