28 December 2014

To hospital!

Don't worry! I went to hospital for pleasant reasons. One may remember we took hundreds of cores of the seas around Ireland in summer. We want to find the contact between sediments deposited by ice and those deposited after the ice retreated (generally shallow marine sediments). And we want to date these contacts to know when the ice retreated. But that's not easy; there isn't much in those sediments that you can date, and the only way of finding it is cutting up the entire core, sieving the sediments, and sending any shells or stuff like that to a lab for radiocarbon dating. But that is a lot of work, and it destroys the cores. Not ideal! It would be so much better if you could somehow see where the good stuff is. And we can! We have external X-ray vision: it's called a hospital.

I had just phoned the local hospital, on the off chance they would be willing to help us out. And to my surprise they were! So just before Christmas I borrowed a university car, drove to hospital with three sections of core in the boot, and got myself a seat in the Radiology waiting area. How would it go?

Soon a lady appeared, who asked if I was Margot. I was! And she took me to a room with a bed in it with a big machine hanging above, and a computer behind a thick glass screen. Exactly what you expect in an X-ray room. So we started zapping the cores! And it's only provisional, but we figured out what settings we need, and what sort of configuration. I'll need a metal measuring tape! It's important to see what part of the core we have in each exposure. They don't fit into one picture; one needs three or for for a 1m section.

Two sections waiting to be X-rayed

The two sections on a cassette

So making a measuring tape with metal labels and tick marks is on my to do list for early next year. And then we can go back a few times and hopefully zap all the interesting ones! We already saw it's worth it; we saw some very useful fragments, and even an amazing articulated specimen, seemingly in live position, which is screaming for being dated. This is making our work so much quicker and more efficient! Hurray for the hospital, and bring on the new year!

The articulated shell, with a paperclip as a marker

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