DFENS: Diffusion Chronometry Using Finite Elements and Nested Sampling ...

• Main Authors: Mutch, EJF, Maclennan, J, Shorttle, O, Rudge, JF, Neave, DA
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union (AGU) 2021
• Subjects: Bá; rð; arbunga; Bayesian inversion; diffusion modeling; finite elements; Iceland; volcanic and magmatic timescales; olivine and plagioclase geospeedometry; Skuggafjö; ll; Skuggafjöll
• Online Access: https://dx.doi.org/10.17863/cam.66547; https://www.repository.cam.ac.uk/handle/1810/319424

AbstractIn order to reconcile petrological and geophysical observations of magmatic processes in the temporal domain, the uncertainties in diffusion timescales need to be rigorously assessed. Here, we present a new diffusion chronometry method: Diffusion chronometry using Finite Elements and Nested Sampling (DFENS). This method combines a finite element numerical model with a nested sampling Bayesian inversion, meaning that uncertainties in the parameters contributing to diffusion timescale estimates can be obtained and that observations from multiple elements can be used to better constrain individual timescales. Uncertainties associated with diffusion timescales can be reduced by accounting for covariance in the uncertainty structure of diffusion parameters rather than assuming that they are independent of each other. We applied the DFENS method to the products of the Skuggafjöll eruption from the Bárðarbunga volcanic system in Iceland, which contains zoned macrocrysts of olivine and plagioclase that ...