Hi Martin, what version of TC are you using?
I spent a LONG time working up a MNNCKFMASTO datafile that works remarkably well for greenschist/epidote-amphibolite facies metamorphosed greywacke/argillites in the Alpine Schist, New Zealand. Mineral compositions aren't great, but garnet compositions are the best of the lot. (P-T path for Alpine Schist, J.Met. Geol. 2008 I think) (I'm on vacation and am just at the moment sitting at a computer that is not my own). If you can pull that paper up, it will have the specifics in it. I do have my computer along, so I can send you an input file the next time I log on.
Mn in grt, chl, ilm.
O needed to included epidote.
avoid sphene like the plague, it is currently "pure" and that is decidedly problematic (Roger and I have that on our lists to work on) Also using sphene without carbonate gives results that I think are silly. 10 or eleven components is a lot, and I certainly found that it was best to work my way up gradually until the result I was getting from TC made sense with what we already thought we kew about the rocks based on previous work. I think I went 7, 8, 9, 10, 11, 12 components, and then settled on 11 as the minimum that worked for the Alpine Schist.
ab + pl lets you include persiterite gap, which in low grade greywacke is essential.
We didn't include graphite, but I am told that including graphite& CHOS fluids is now possible...I wouldn't be too surprised if ep-out does things to graphite stability, but I haven't checked that.
Julie Vry
________________________________
From: Metamorphic Studies Group [[log in to unmask]] On Behalf Of Martin Rigby [[log in to unmask]]
Sent: Friday, July 03, 2009 12:50 AM
To: [log in to unmask]
Subject: MnNCKFMASHT datafile
Dear all
Does anyone have a MnNCKFMASHT datafile for THERMOCALC?
Cheers
Martin
Dr Martin J. Rigby
Department of Geology
University of Pretoria
Pretoria 0002
Republic of South Africa
|