From the PhD students I met in Edinburgh I got the impression it was quite relaxed and I'd be able to come and go when I pleased. Nope. Not this project. With all the lab work, reading, microscope work and re-learning how to study most of my days begin at 9 and finish after 7 - already it seems a mammoth task ahead of me. But it's great to be doing something I love!
Although slightly more sleep would be nice!!!
Ivan has a lot of samples from Volcan de Colima already, so I've been able to start looking at the deposits which is brilliant - a lot of PhD students don't start looking at data until half way through their first year. The samples we have are ash and tephra deposits (pumice).
Some of the pumice has been sliced very finely (roughly 30 microns thick) in order to look at through a microscope. The different minerals which make up the rock have unique characteristics. Certain minerals only form under particular conditions, so from this we can work out the temperature of the magma when the minerals formed which can tell us the eruption temperature; the water content of the magma - the higher the water content the more explosive and violent the eruption etc. So I have been looking at these through the optical microscope, identifying minerals and textures, and on the electron microscope which gives exact compositions of the minerals.
The rest of the pumice which isn't kept for archive has been crushed to a fine powder. Some of the powder was analysed (before I started) for whole rock geochemistry. This gives the exact chemical composition of the whole sample i.e. iron content, aluminium content, silica content etc. We use this data to work out what changes have happened to the magma in the magma chamber. If it sits there for a long time, minerals crystallise, wall rock is melted, new magma is added from depth. With all these processes going on, the magma's chemistry is constantly changing which is recorded in the erupted tephra and ash. As the analyses were done before I started, I've been plotting various graphs to try and work out the processes which have been going on in the magma chamber.
One of the main things keeping me busy has been strontium isotope analysis. It amazes me how much time and effort goes into getting one little number! I've spent days in the lab measuring out powder, dissolving it in acid, and extracting the strontium - it takes an awful lot of patience and a very steady hand!!!! But I got some results, woo hoo!! Although nothing publishable yet!
So after all this beavering away, I am getting my trip to Mexico!!! I'm off on Friday to Colima to work on the volcano and collect my own samples! HOORAY!!!!!! Although, I'd like to reassure you that I won't actually be going on the volcano as it is too dangerous. I'll be on the extinct volcano, Nevado de Colima (which is actually Colima's older and rather dead brother), which is higher, and so out of danger, than the active Colima Volcano.
So keep checking out my blog, and I'll post updates and photos of my trip!
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