This is Simon’s blog reporting on the development of a new single-clinopyroxene HPx-eos.
Lots has changed! Calibrating cpxwing turned out to be a quite difficult task, as there are complex interactions with other major phases, in particular with amphiboles at blueschist facies conditions. While fitting the models we discovered strong correlations between the end-member and mixing properties, which once established, helped us to control the interactions between amphiboles and clinopyroxene.
Using Eleanor’s omphacite model as reference we redefined several core W’s in cpxwing, allowing us to solve a recurring problem where clinopyroxene is calculated at conditions where glaucophane should be dominant. Previously this issue actually prevented us from calculating glaucophane-schists!
Currently we are working out some final tweaks of the new model, including some minor changes of the amphiboles. We are aiming to write-up in the coming months to finally unleash cpxwing into the petrological world!
Simon’s short postdoc has (unfortunately) come to an end.
Time it was, and what a time! I had an amazing experience in this beautiful city – even though I spent more time at home than I would have hoped for.
I am extremely grateful for this dive into the wonderland of model development. Eleanor & Roger showed me a glimpse of how deep the rabbit hole goes – the bottom is not yet in sight! I am honored to be a part of this team and to have learned from these great people. Eleanor and myself will keep close contact and to work on cpxwing and many more exciting projects down the road.
Melbourne, I will miss your chatty lorikeets and amazing coffee. A year really is too short to get to know you.
New to phase diagram modelling? Always wanted to know how petrogenetic grids were made but didn’t dare to ask? Worry no more! Here’s the first of a series of tutorials, a simple, step-by-step guide to build your own P-T projection with THERMOCALC!
This is Simon’s blog reporting on the development of a new single-clinopyroxene HPx-EOS.
The new model is designed to replace pre-existing versions that do not currently overlap in P—T—x space.
So far three clinopyroxene EOS exist. Ordered diopside—omphacite—jadeite (Green et al., 2007) is for coexisting sodic—calcic clinopyroxenes. It accounts for order—disorder on the octahedral M1 and M2 sites, but not on the tetrahedral T sites. It is appropriate for high pressure but unsuitable for high temperatures.