Thermodynamic Modeling of Magmatic Processes with alphaMELTS 2
This is the home page for the two day workshop that was to be held at the Goldschmidt 2020 conference,
and that will now be held online instead.
For the NSF sponsored two to three day workshops held at Caltech, and elsewhere, please see the
alphaMELTS NSF workshops that we have held in the past.
We were hoping to run a two day workshop, prior to Goldschmidt 2020, on the use of MELTS software
for calculation of phase equilibria and tracking of trace elements during igneous processes.
The workshop was cancelled, but we are holding a three day workshop online as part of the Geochemical
Society's Fall Virtual Workshop Program.
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. Instructors Paul Asimow and
Paula Antoshechkina from Caltech are the designers and maintainers of alphaMELTS 2 and related software, and will cover
background to the MELTS models, software installation and use, real world examples, as well as some undocumented tricks
that are important to getting reliable results from MELTS calculations.
Although there are a variety of ways to access MELTS models, this workshop will focus on the newly released alphaMELTS 2
interface and access to alphaMELTS from MATLAB, Python, and (if there is sufficient interest) R programming environments.
alphaMELTS 2 is a text-based front end to the rhyolite-MELTS, pMELTS, and pHMELTS models, with built-in trace element
calculations and a variety of unique features and workflows. This workshop will differ from previous ones in that it will
be structured so that users can attend either or both days, depending on their needs and previous experience. Day 1 will
focus on introductory material and basic functionality for users new to alphaMELTS. Days 2 and 3 will focus on more advanced features,
larger-scale calculations, and special problems suggested by attendees. We will also have time for a "MELTS clinic" with
one-on-one support or break out groups for users' own MELTS calculations (including any using the graphical user interface,
alphaMELTS 1.X etc.). Day 1 will constitute sufficient preparation for a novice to be able to appreciates Day 2 and 3. Users who
have previously attended an alphaMELTS workshop, especially one of the recent NSF-sponsored GeoInformatics short courses,
should also find Days 2 and 3 helpful.
Title: Thermodynamic Modeling of Magmatic Processes with alphaMELTS 2 Organizers: Paula Antoshechkina, Paul Asimow (Caltech) Date: November 23rd - 25th, 2020, 10.00AM - 2.00PM each day Venue: Online Registration fee: $90/$80 (Professional) / $45/$35 (Student), per particpant; payable by credit/debit card Workshop registration deadline: November 19th/20th, 2020 (depending on timezone)
Registration and payment (if appropriate) for the workshop are available through the Geochemical Society's website.
You will need to sign up as a visitor to the website, but you do not need to be a Geochemical Society (GS) member to register
for the workshop. More information can be found on the alphaMELTS 2 workshop details
page. Included there is contact information for getting free registration if you are from a low-income to lower-middle-income
economy country, and for getting reduced price registration if you are member of the European Association of Geochemistry
(EAG) or Mineralogical Society of America (MSA). GS members automatically receive the reduced rate.
Workshop programme
We intend to cover a range of topics during the workshop, including:
Background to, and strengths and limitations of the computational phase equilibria approach taken by the
MELTS family of algorithms
Comparison of MELTS models (rhyolite-MELTS 1.0.2, 1.1.0, 1.2.0; pMELTS; pHMELTS) and suitability for particular
applications
Common errors in running the models and important ways to apply them efficiently and accurately
Introduction to the alphaMELTS 2, and alphaMELTS for MATLAB/Python interfaces
The trace element engine in alphaMELTS 2, including the expanded D(P,T,X) functionality of alphaMELTS 2.
traceDs, a database of experimental studies involving trace element
distribution between liquid, and solid phases, and how to use traceDs search results in 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
Talks describing the models and software will be kept brief to allow more time for first hand experience with
the software. Particular features will be higlighted on the platforms for which they are most convenient (e.g.
alphaMELTS for trace elements; alphaMELTS for MATLAB for open system behavior). Application to magma chamber processes
and mantle melting will be discussed, and short demonstrations will be included as illustrations. 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.
This was the tentative schedule for the in-person workshop. Details of the online
schedule are still be determined, but will be updated here soon:
20th June 2020: Introduction to alphaMELTS 2, and alphaMELTS for MATLAB/Python
AM session 1: Welcome to the workshop; brief overview of MELTS software programs that we will be
using and how to install them
9.30 AM: Talk on model construction for the MELTS family of algorithms; modeling modeling magma chamber
processes, including liquid lines of descent (LLD), assimilation and fractional crystallization (AFC)
10.30 AM: Coffee break (exact time TBD; software installation clinic)
11.00 AM: Practical session, getting started with alphaMELTS 2; how to generate input files, and plot results,
modeling fractional crystallization, LLD etc.
12.30 PM Lunch break
PM sesion 1: Continued from previous session, modeling magma chamber processes with alphaMELTS 2
3.00 PM: Refreshments served (exact time TBD)
PM session 2: Introduction to alphaMELTS for MATLAB/Python*: modeling mantle melting, phase diagram mode etc.
5.00 PM: End of afternoon session
21st June 2020: Trace elements and advanced features in alphaMELTS, MELTS clinic
AM session 1: Refresher/update on new alphaMELTS 2 features, and trace elements in alphaMELTS 2. Very brief
introduction to ENKI and the tools hosted there, and discussion of how alphaMELTS and other MAGMA@Caltech tools fit in with the
ENKI project (Paula Antoshechkina)
10.30 AM Coffee break (exact time TBD)
AM session 2: Advanced calculations: e.g. assimilation and other (user-defined) open-system behavior, polybaric
mantle melting of two sources that are thermal but not chemical equilibrium
12.30 PM Lunch break
PM session 1: Work through problems suggested by participants. Possibility to break out into smaller groups with common
interests or to work individually with instructors
3.00 PM: Refreshments served (exact time TBD)
PM session 2: Continued from previous session, followed by group discussion - concluding remarks, feedback, and
suggestions for features that workshop participants would like to see in alphaMELTS 2 soon
5.00 PM: End of afternoon session
*Note that having access to MATLAB is not a requirement for participation. Python alternatives
for each exercise will be available, if needed; the MATLAB and Python interfaces to alphaMELTS are near-identical.
We will 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 not seem to work (not necessarily in alphaMELTS 2; we can offer support for the GUI,
alphaMELTS 1.X, MELTS for Excel etc.). Alternatively, simply bring a composition (major elements in wt% or grams of oxides; trace elements,
optional for alphaMELTS, in ppm) and conditions that you would see calculated.
Workshop Organizers
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.