1. Work in small groups or (if you're confident) alone. Get the file picrite.melts just the same as last week and verify that it is set up to run at QFM, with the composition shown in Figure 1.

Each group should crystallize our picrite composition at a different pressure. At the very least I would like to see 1-atmosphere, 500 bars, 1 kb, 2 kb, 4kb, 6kb and 10 kb.

Run the models to 99% crystallized in both fractional and batch mod, and send the output files to me or put them in my public directory. Clearly marked! In the readme.txt file be sure to include.

At the next class meeting please hand in a short summary of the effect of pressure on the evolution our picrite composition. We will discuss in the lab at what pressure the important effects occur, and approximately what they are. Feel free to share data and results with the other members of the class, but do the plotting and writing yourself.

Use the various MELTS output files to make figures that show the pressure effects clearly. Your discussion should make clear to the uninformed geologist what the pressure effects on basalt evolution are -- keeping in mind that this is a model system and not necessarily the real world.

Figure 1: Starting composition for problem 1.