A stochastic sampling approach to zircon eruption age interpretation

This is a Preprint and has not been peer reviewed. The published version of this Preprint is available: https://doi.org/10.7185/geochemlet.1826.

Downloads

Download Preprint

Supplementary Files
Authors

C. Brenhin Keller , Blair Schoene, Kyle M. Samperton

Abstract

The accessory mineral zircon is widely used to constrain the timing of igneous processes such as magma crystallization or eruption. However, zircon U-Pb ages record zircon crystallization, which is not an instantaneous process. Zircon saturation calculations link zircon crystallization, temperature, and melt fraction, allowing for the estimation of zircon crystallization distributions as a function of time or temperature. Such distributions provide valuable prior information, enabling Bayesian estimates of magma eruption time and allowing for comparison of the relative accuracy of common weighted-mean and youngest-zircon age interpretations with synthetic datasets. We find that both traditional interpretations carry a risk of underestimating the uncertainty in eruption age; a low mean square of weighted deviates (MSWD) does not guarantee the accuracy of weighted mean interpretations. In the absence of independent confirmation that crystallization timescale is short relative to analytical uncertainties, a Bayesian approach frequently provides the most accurate results and is least likely to underestimate uncertainty. Since U-Pb zircon studies now routinely resolve geological age dispersion due to increasing analytical precision, such considerations are increasingly critical to future progress in resolving rates and dates of Earth processes.

DOI

https://doi.org/10.31223/osf.io/aws79

Subjects

Earth Sciences, Geochemistry, Physical Sciences and Mathematics, Volcanology

Keywords

Geochronology, Bayesian statistics, zircon age distribution

Dates

Published: 2018-10-03 18:32

Older Versions
License

CC BY Attribution 4.0 International

Add a Comment

You must log in to post a comment.


Comments

There are no comments or no comments have been made public for this article.