Matthews, Wong, Gleeson. Preprint available on EarthArxiv, doi: 10.31223/X5JP7X.

PyMelt is our new open-source python library for calculating the melting behaviour of lithologically heterogeneous mantle. Built into pyMelt are a number of published models for the melting behaviour of individual lithologies, including the Katz et al. (2003) lherzolite melting model, and the lherzolite and pyroxenite melting models that we developed in Matthews et al. (2021), and others. PyMelt implements the equations of Phipps Morgan (2001) to calculate the melting behaviour when these lithologies are in complete thermal equilibrium with one another.

There are also numerous methods built on top of this for calculating other melting region parameters, for example the trace element abundances in lavas, the crustal thickness produced at spreading ridges, or the magmatic productivity at intra-plate settings. To get started check out our interactive cloud-based tutorials on myBinder!

Wieser, Iacovino, Matthews, Moore Allison, Earth & Space Science 9(2), e2021EA001932. doi: 10.1029/2021EA001932

One of the new capabilities offered by our VESIcal magma solubility modelling software is the ease with which we can compare the predictions of different solubility models and perform sensitivity tests on parameters about which we make assumptions. In this article we review the most widely used solubility models and examine the origins of the differences in their predictions. We also use VESIcal to demonstrate the effect of neglecting the contribution of dissolved CO₂ when calculating saturation pressures in H₂O-rich arc systems. VESIcal also makes it very easy to rapidly calculate many isobar-curves, and we use this functionality to critically assess the utility of plotting melt inclusion suites on top of a single set of isobars.

To read more about the VESIcal software, check out the first part of the VESIcal publications. VESIcal can be used in the cloud by signing up to the ENKI server.

Soderman, Shorttle, Matthews, Williams, Geochimica et Cosmochimica Acta, 318, 388-414 (2021). doi: 10.1016/j.gca.2021.12.008

In this paper we assessed the utility of novel stable isotopes (Mg, Ca, Fe, V, and Cr) in lavas for tracing mantle lithological heterogeneity and melting processes, and in particular the prospects for combining multiple stable isotope proxies to uniquely identify these processes. Major element isotope systems may better respond to lithological heterogeneity because, unlike trace elements, their concentrations do not vary by orders of magnitude between different mantle components.

This work (led by PhD student C. Soderman) significantly expanded the capabilities of the stable-isotope fractionation code I originally developed (and published a proof-of-concept).