Team news – October 2020

A quick round-up of news on team members and projects related to the HPx-eos and THERMOCALC:

Simon Schorn recently moved to Austria, where he has been awarded a grant to work at the University of Graz on fluid infiltration during metamorphism. Congratulations Simon! He had a strange year as Eleanor’s post-doc in Melbourne, spending two thirds of it in actual or effective lockdown, but we look forward to continued collaboration and a belated farewell dinner once international travel resumes. While in Melbourne, Simon did excellent work on cpx- and amphibole-bearing equilibria in subsolidus metabasite systems, making key insights that will help us with modelling the blueschist facies. His monstrous new cpx x-eos, cpx-wing, just needs its laser cannons added before it’s ready for take-off.

Springtime in Melbourne. I need to work on my eucalypt identification.

Corinne Frigo has just completed a marathon experimental programme at ANU, which has highlighted where we could improve the igneous x-eos in dry peridotite systems. We appreciate Corinne’s results all the more because she has persevered with her work through bushfires, a devastating hailstorm that put her lab out of action, and the pandemic. Well done Corinne!

John Mansour has done some magnificent work on TawnyCALC – and the delay in completing and releasing it is entirely my fault, sorry John! More news on this soon.

Katy Evans rightly pointed out that the set of hydrated ultramafic x-eos used in Evans & Powell (2015; J Metam Geol 33 649-670) should be on this site. She has been preparing the input files for this, and they should be ready to go shortly.

RP is focusing on updates to THERMOCALC 3.50. He has implemented a number of changes to the scripting, aimed at making it simpler, more transparent, and better at helping the user when things go wrong. He is currently restoring some functionality related to calculations with fluids that has been lost in recent versions. Once a new version of the program is ready for release, we will also be able to make Simon’s long-awaited pseudosection tutorial available, with up-to-date scripts.

Tim Holland continues to develop the dataset and igneous-set x-eos. In particular: an update for peridotite melting relations; updates for Ti in various phases (ru, ilm, melt); updating spinels with Eleanor; adding CO2 and S to melts, the last two in quite early but promising stages; working with RP on a simple ternary feldspar model that is continuous in composition (without the distinct C1/I1 phases); and on a nepheline model with Owen Weller.

Finally, in between battles with high-Ca opx (see upcoming post) and cpx-wing, Eleanor Green has been investigating some xenolith data from the Lesser Antilles volcanic arc, collected by Jon Blundy’s team at the University of Bristol. The xenoliths sample the upper part of the magmatic system that created each island, and their whole-rock chemistry and mineral assemblages contain insights into how this magmatic system varies along of the arc. These rocks are very high variance – they have many dimensions of significant compositional variability, but few phases – so forward modelling has proved too challenging for the current generation of x-eos. Fortunately, this is where the (S)COlP barometers come in useful.

Profiles of the team can be found here. We welcome questions and comments, via the comment form, or, even better, the Discussion Group.

COVID-19 hiatus

Dear friends, colleagues, and all HPx-eos/THERMOCALC users,

There will be a hiatus in news, as, in common with the rest of the global community, we work to handle the effects of the COVID-19 pandemic on our professional and personal lives. I hope to return to website developments in June, after the end of semester.

Wishing all of you the very best at this difficult time,

Eleanor and the rest of the team


DRAWPD 1.18 can now be downloaded, including a working Windows version. Did you know that DRAWPD lets you plot coloured and ornamented lines? (as of version 1.16 I believe). An example of this is bundled with the download.

We continue to work on comprehensive .csv output for all THERMOCALC calculation modes, to facilitate more flexible plotting.

Update 8-2-2020: There is now drawpd documentation available at the link above, along with a slightly updated version of DRAWPD 1.18 (small changes to what appears on screen, nothing likely to affect the user).

Many thanks to those users who confirmed that the previous version was now working! Please continue to report any problems.

THERMOCALC 3.50 updates

Happy New Year to all our users!

To celebrate, there is a new version of THERMOCALC 3.50 beta available.

As usual, the development of tc350 is partly driven by our long term plans, and partly in response to problems and requests raised by users. In this case, many of the changes since December’s release are user-driven (this is great – please keep commenting!). They mainly relate to new scripts, making input/output more flexible, and also to the printing of more comprehensive output. The changes are detailed in the release notes bundled with the software download – please do read these carefully!

TawnyCALC is coming

The tawny frogmouth. Possibly Australia’s
most delightful bird? Although competition
is fierce. (Photo by James Barron.)

Looking ahead, Eleanor and John have just been discussing TawnyCALC, one of two upcoming extension packs to THERMOCALC.

TawnyCALC will automate various problems that involve driving THERMOCALC along a path, doing dogmin calculations at each step. Fractionation calculations are an obvious example. We currently plan to have it running online via a Jupyter interface.

The second extension pack, TammaCALC, will allow a set of phase diagram calculations to be made simultaneously and repeatedly. It will facilitate various uncertainty calculations.

More to come in 2020!

THERMOCALC 3.50 is coming

RP and Eleanor are almost ready to commit to uploading a beta version of THERMOCALC 3.50. This is not all good news for users, since it requires its own axfile format, containing more information and stricter syntax. Nevertheless we’re delighted with it, since, among other things (lots of things under the hood), it features:

  • fully transparent x-eos descriptions in the -it file (i.e. sufficient to implement the x-eos elsewhere)
  • new csv format output for more flexible plotting
  • avT reinstated; both avP and avT now select reactions for their small uncertainties rather than their linearity (had anyone noticed avT was missing?!)
  • more controllable and extensive output from dogmin calcs, dataset extraction mode, and multiple-reaction thermobarometry.

Many users may never have had a copy of version 3.46 or 3.47, so may not yet have discovered the -ic output file. In here, THERMOCALC prints full details of the calculation, including compositional/structural information in terms of molar oxides and site fractions, and numerous thermodynamic variables. What other/different output should we have?

Modelling open Earth systems

We hope soon to introduce THERMOCALC-powered open-system modelling facilities, based as always on the phase relations encapsulated in the HPx-eos. These facilities will be standalone, but will also link into the Underworld geodynamic modelling toolkit.

Eleanor is trying to wrap her brain around how to handle chemically-open systems in solid-Earth geoscience as a fully general problem, and bridge the communication gap with her colleagues in software development and geodynamics. More news later this week…