By Kate Boston
There is something intensely satisfying about getting new data. It is proof – tangible testament (no matter how you feel about your project, or how you think you are progressing, or not) – that shows that the months of work have produced something. It doesn’t matter if the data are good bad or indifferent. It is there and it is real. And if it doesn’t make sense, usually you just get more data – do more experiments, more analyses – in the hope that it’ll all work out in the end.
At the moment I am looking at zircon SHRIMP data. I feel especially positive about this data because zircon is the poster-child mineral for SHRIMP geochronology. Why? Because it just works. You do your analysis; you get an age. Done (in truth there are a few more steps than that, but only a few).
What that age actually means is a bit tricky, and for that you need a few different machines, techniques and tricks. But that’s another story for another time.
I also like zircons because cathodoluminescence (CL) images (pictured) tend to be quite pretty.
I am so used to working with minerals (eg allanite and monazite) that have their own set of problems and challenges. You end up with a whole new saga just trying to convert your raw SHRIMP data into ages. It is positively refreshing to get a mineral where you don’t have to work out a bah-zillion other things before you even know if you can even get an age out of the darn mineral.
As I said before, it doesn’t matter that my zircon ages look atrocious, spanning from 30 million years old to 500 million years old. I don’t know what it means and chances are they probably don’t mean anything in the most part (mixed analyses, partial resetting of isotopes, radiation damage from uranium, and other complicated whats-its and junk).
I shan’t worry about that for now. Instead I shall just marvel at the fact that zircons can retain their isotopic information for over five hundred million years. That’s a pretty long time, even for a geologist.