Being new to this social media/blogging game I’ve been doing some research in what makes a post popular & as far as I can see the answer is cute puppies & kittens. Now the Knowe of Swandro has many fine attributes – exceptional archaeology, wonderful diggers, charismatic directors etc. etc. but it’s sadly deficient in the cute puppy/kitten department. Thankfully help is at hand as I personally am in possession of considerable number of same, so before we get down to the archaeomagnetic dating, here’s a quick puppy fix, in the form of Bran the lurcher:
Now I’ve got everyone’s attention we can turn to the serious business of the subject of our next photo, samples being taken for the archaeomagnetic dating of the middle of an Iron Age hearth at Swandro:
Archaeomagnetic dating is a pretty clever technique, which relies on a curious fact that if you heat something with ferromagnetic properties up hot enough, when it cools down again it fixes the direction of the earth’s magnetic field as it was on the day it cooled down. So if you get something like a big enough undisturbed hearth, like the one in the picture above, you can take samples, marking the position of true north on the top of the sample tubes, then whizz them off to the laboratory where some very clever people (probably wearing white coats), do something really clever & tell you how old it is by working out when the magnetic field the samples contain was generated.
Now I’m aware that this is not the most comprehensive explanation of the subject, but thankfully there’s a full explanation in this handy downloadable guide Archaeomagnetic Dating Guidelines on producing and interpreting archaeomagnetic dates.
Next time....cute kittens!