Thermodynamic Modeling of Volcanic Systems with alphaMELTS 2
This is the home page for the two day workshop at the IAVCEI 2021 meeting;
for the NSF sponsored two to three day workshops held at Caltech, and elsewhere, please see the
alphaMELTS NSF workshops page.
We are pleased to announce a two day workshop on the use of MELTS software
for calculation of phase equilibria and tracking of trace elements during igneous processes.
The MELTS family of algorithms are widely used by
petrologists and geochemists to predict the outcomes of melting and crystallization processes, to compare with
experiments or to design experimental campaigns, to assess the energy budgets of igneous processes, to teach the
principles of igneous petrology and geochemistry, and more.
This short course will introduce users to the full range of MELTS models, illustrate the capabilities
and potential applications of individual models, demonstrate the available interfaces, and give participants
first hand experience running the software and tools. This workshop will differ from previous MELTS workshops
in emphasizing trace element calculations. With the traceDs database recently being made public
and the new trace element engine for alphaMELTS 2 / libalphaMELTS scheduled for release during the coming months,
the workshop will represent
the cutting edge for thermodynamic modeling of phase equilibria and calculation of trace element budgets in magmatic systems.
New users, as well as those with some prior experience with
MELTS, should each find the workshop helpful for applying MELTS to their own research and teaching needs.
Title: Thermodynamic Modeling of Volcanic Systems with alphaMELTS 2
Organizers: Paula Antoshechkina, Paul Asimow (Caltech)
Date: February 13th - 14th, 2021, 9.00AM - 5.00PM each day
Venue: Room TBD,
Registration fee: TBD per particpant, per day (payable by credit/debit card)
We intend to cover a range of topics during the workshop, including:
- Background to, and strengths and limitations of the general computational phase equilibria approach
- Comparison of MELTS models (MELTS; pMELTS; Rhyolite-MELTS; pHMELTS) and suitability for particular
applications; also the new, improved H2O-CO2 fluid model in rhyolite-MELTS
- Common errors in running the models and important ways to apply them efficiently and accurately
- Introduction to the various user interfaces: the MELTS downloadable graphical user interface
(GUI); the alphaMELTS text-based interface; and MELTS_Excel, which uses macros and MELTS web services
- A demonstration of PhasePlot, a software package that allows rapid visualization of equilibrium
phase relations (including Rhyolite-MELTS based ones)
- Quick overview of other interfaces available to advanced users or soon to be available
(MELTS RESTful web services; libalphaMELTS / libpHMELTS)
- LEPR, a database of results of published experimental studies involving liquid-solid phase equilibria
relevant to natural magmatic systems, and traceDs, a database of experimental studies involving trace element
distribution between liquid, solid and fluid phases.
- The trace element engine in alphaMELTS, including the expanded D(P,T,X) functionality of alphaMELTS 2.
- Brief discussion of the next generation of models (e.g. high pressure phase equilibria in xMELTS)
and planned extensions to the existing interfaces
Introductory sessions will include talks describing the models and software, traceDs database and available
trace element calculations. Application to magma chamber processes and mantle melting will be discussed, and
short demonstrations will be included as illustrations. Links to software front-ends that will be used at the
workshop are available by clicking the Links tab above (updated versions will be posted nearer the time).
We encourage you to download and install the software in advance and to test the installation
using the appropriate 'Quick Start using MELTS' tutorial example.
Tutorial sessions will feature hands-on examples to demonstrate alternative interfaces for running MELTS calculations,
including downloadable software, web services and browser portals. Some calculations (such as MORB crystallization)
will be performed on all the front-ends so that, so that you can see similarities and differences. Examples
from the introductory sessions will be expanded on, and some special calculations will highlight features that are
only available (or only convenient) on individual platforms. All input files will be available for downloaded,
nearer the time, by going to the Links tab above.
We will also have time for Q&A with individual workshop
organizers to address participants' particular interests during the break-out sessions. Please feel free to
bring examples that you would like us to look at. This could be a calculation that you have attempted
that does seem to work or simply a composition (major elements in wt% or grams of oxides; trace elements,
optional for alphaMELTS, in ppm) and conditions that you would see calculated.
Links to software front-ends that will be demonstrated at the workshop
are available by clicking the Links tab above. We recommend that you install whichever front ends you are
interested in before the workshop; you can test the installation using the appropriate 'Quick Start
using MELTS' tutorial example. If you cannot install the software before the day, or prefer to wait and see
which interface you prefer, then we will have thumb drives available with
copies of VM alphaMELTS, which also includes the
If you intend to use VM alphaMELTS please try to have VirtualBox (free; 32- and 64-bit versions available for Mac,
Linux and Windows) installed on your laptop before the start of the workshop.
The thumbdrives will also have copies of the presentations and and sample input files. Older versions of these
files, from a similar format workshop held before the Goldschmidt conference in 2015, are available
by clicking the Links tab above. The files will be updated nearer the time of this workshop.
Some examples (such as MORB crystallization) will be provided for more than one
front-end, so that you can see similarities and differences.
Paula Antoshechkina (née Smith) is
an Associate Research Scientist at Caltech. She is responsible for most of the alphaMELTS front-end, forum and
MAGMA website. At the moment she is focused on pMELTS+CO2 and other calibrations, libalphaMELTS
and libpHMELTS interfaces, and various projects that fit between the tools
available on the ENKI portal and traditional MELTS software.
Paul Asimow is Professor of Geology
and Geochemistry at Caltech. He developed pHMELTS and many of the tools since incorporated into alphaMELTS.
He has supervised a number of students and postdocs with MELTS-related projects, both to extend and improve
the underlying thermodynamic models and to apply the software to real world magmatic processes. He is
also involved in shock-wave experiments and theoretical calculations on silicate liquid and minerals.