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.