Devonian time scale modeling

This project started with a simple goal: date some key Devonian ash beds with high precision U-Pb zircon geochronology to improve the Devonian time scale. Then, when it came to contextualizing those ages, we realized we could do more to refine the Devonian time scale than simply throwing out these ages for someone else to integrate into the time scale. We used a Bayesian framework to create an age-depth model for all of the Devonian, and we integrated our radioisotopic ages, radioisotopic ages from the literature, floating astrochronology Stage durations, and conodont biostratigraphy to create a robust model that allows us to determine an age and uncertainty on any biostratigraphically constrained position. We built off of Robin B. Trayler's modifiedBChron R package to make our age-depth models.

For this project we also examined how different starting assumptions will influence the resulting time scale. We found that this modeling process can “see through the noise” and will produce remarkably similar final time scales no matter which conodont biostratigraphic scale with which you start.