06 October 2010

Nitpicking for diehards

Think of someone who spends their working life bent over very small objects! Who rummages around in very small containers. Whose eyes are focussed on the smallest of entities. Are you thinking of a micropalaeontologist now? If so: makes sense! If not: what WERE you thinking of? Not of a tephrochronologist, by any chance?

I just found out today it gets much more nitpickier than what I am used to. And I am used to quite something. My work tends to be based on thousands and thousands of thingies about one quarter of a millimetre in size. But today things got beyond that level. I ended up sieving samples for tephrochronology.

The sieves I use for sieving my samples for foraminifera analysis

Tephrochronology boils down to the use of volcanic ash (tephra) layers for the dating of sediments. One of my field sites is on Iceland, so there’s ash galore. And now I’m specifically trying to find the ash from one specific eruption, to provide a dating point in my stratigraphy. So I took peat samples, burnt them down, and then tried to separate the volcanic ash from the organic ash (the peat I had just burnt) by sieving over a 25 μm mesh. 25 μm! And the sieves (I used a 63 μm sieve as well, to get rid of “large” particles) were so cute! I suddenly feel like micropalaeontology is for big, muscular, coarse brutes. Man, these tephra people must have some patience! And some fine motoric skills...

The sieves I now use for sieving out tephra

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