New skills at work

Last year, with the help of archaeologist Mats Blohmé, metal-detector survey of about 1 hectare was conducted at the Kvarnbo Hall site. The objective then was to identify the areas with the presence of prehistoric metal objects and, thereby, gain an understanding of both the character and date of the site as well as of the horizontal distribution of finds. And, as the result, well, some pretty nice objects were discovered dating from the late 6th century AD to the end of the Viking Age, pointing towards the existence of an elite settlement at the site. However, as these finds were distributed all over the area studied, no potential hot-spots were located. Furthermore, as the survey did not include the whole field, the site was not delimited. Thus, with my newly acquired skills, I have decided to continue metal detecting surveys at the site and the field as a whole.

While working at the site, same as last year, iron is discriminated, i.e. I have chosen to set the machine to ignore (small) ferrous objects, such as nails. But even though the machine allows me to discriminate an audio signal from a ferrous object, in case the remote control is actively used, it is still visually showing if there are iron targets in the area of search. Thus, I would say that my discrimination is not so strong, and I actually get a pretty good picture about the amount of metal in the area. At the same time, as the field is scattered with iron objects, I am afraid that there are quite a few cases when valid signals have been masked by iron targets as iron kind of tends to do that… not to mention that I am just a beginner in the highly addictive world of metal detecting. Well, eventually, I will work out a setting that would be optimal for my purposes! And I am fine with the idea that I will probably have to search through the site for several times anyways.

So far, I have dug about 150 targets at the Kvarnbo Hall site. Together with the work done last year, you would think that the total amount of metal objects documented in the field would be around 200. However, as all of the finds without direct archaeological relevance to the Iron Age and Early Medieval times were redeposited at their find-spots during the survey last year – after the find circumstances were documented with GPS and photographs – this year, I have had an opportunity to rediscover exactly the same objects 😀 To document exactly the same objects is obviously not so exiting, but, from the bright side, this fact enables observations about the movement and displacement of the objects during the time in-between their disclosures. And this is actually quite fascinating, as the field has been ploughed and harrowed in-between the surveys. Interestingly, three different kinds of object that I chose for closer examination from that point of view show minimum movement (see also picture below):

  • the 2015 find-spot of a button is only 1,3 meters SE from the spot it was discovered in 2014,
  • the 2015 find-spot of a spoon is 1,3 meters NNW from the spot it was discovered in 2014,
  • the 2015 find-spot of a big junk of modern iron is 1,4 meters N from the spot it was discovered in 2014.

This data makes me wonder if there has been any significant movement at all during the year and a half that has passed in between the surveys. Maybe, it is mostly the margin of error with the GPS that I have used?

Förflyttningsillu

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One thought on “New skills at work

  1. noblogg4

    Cool! So the spoon and the big junk has moved in the same direction, and the button in the other? Otherwise it looks like a very structured displacement. And I suppose you used the same quality GPS the whole time? DGPS or RTK GPS? Then 1,3 m sounds like quite a lot for GPS error. Maybe worth trying to compare a few other point you can find and see if they differ too – can you see the trenches still? Interesting taphonomy otherwise!

    Cheers
    Daniel

    Reply

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