
Today Emma Karlsson of the Östergötland County Museum brought a much wished-for RTK-GPS to site and instantly solved the biggest conundrums on our dig. We have Andreas Viberg’s detailed geophys plan of the building we’re investigating. But we have not had an exact GPS device to tell us where we are on that plan when wandering around site.
In our trench we have expected to find three really big sunken features: a hearth in the middle and two roof-support postholes. But we have found only one feature there. Size, shape and surface fill were right for a hearth. Starting from this assumption we have dug around fruitlessly for the postholes. But as Ola Lindgren and his friends went down into our single huge feature, it looked less and less like a hearth. No charcoal. Too deep. WAY to deep. Hey, where are Sofia and Ivan who work on that feature?! Oh, they are no longer visible above ground when they dig.
Enter Emma and her GPS skills. The enormous feature that swallowed the students is one of the roof-supporting postholes. Its original fill of large boulders has been removed, and replaced with something that (as Ola suggests) looks like 20 sqm of trashed floor pavement with sundry dropped objects. The other posthole is sitting three meters away under some innocent-looking soil that we thought were the top of the platform mound. And the hearth is only half inside our trench.
And another thing. The floor pavement they raked into the posthole after tearing the mead-hall down contains nothing that has to date from after the end of the Vendel Period in the 790s. Intensive metal detecting by skilled detectorists across our 200 sqm trench has not turned up a single one of the Islamic silver coins that flood Scandinavia from the 790s onward. Was the Aska mead-hall on its platform mound torn down before the start of the Viking Period? Where then did the royal inhabitants of the village’s extremely rich 800s and 900s graves live? And what were their ideas about the platform mound?
Lesson learned: I am never digging a site with geophys data again without an exact GPS device to tell me where I am on the GPS plot.
I worry about excavation collapses when they get that deep. Explain to me why I am wrong to worry.
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The material is small stones cemented in a clayey matrix, not prone to collapse. But I would not have sent the studets deeper than 1.5 metres, which is where we found the base of the posthole.
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I will worry less, then.
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Sounds like an excuse for a grant application for a short season of excavation in summer 2021 before you move to a new site?
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Are the double hole from the big hall and the really big hall, or something else?
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It’s just one enormous posthole. We have divided it in 4 and excavated two opposite quadrants.
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As you are wrapping up, the students may need lots of water. Rig up tarps for shade?
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Bengt Essen, the last remaining Swedish volunteer that participated in the Winter War between Finland and the Soviet Union has died, the day after he turned 100.
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Tomorrow seems to be the last hot day. Then we get a week with cool air. Then it is September and we can no longer pretend it is summer (Martin may get more clement weather).
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