I'm almost done with the report from my excavations at SÃ¤ttuna in Kaga last September. Here's an excerpt.
Finds and radiocarbon dates allow us to identify five phases on-site, two of them corresponding to the dates of the metal detector finds that occasioned the excavations.
- Late Mesolithic: finds and features with one radiocarbon date.
- Middle/Late Neolithic: one hearth with a radiocarbon date, no finds.
- Mid-1st Millennium AD: a pit and a hearth with two radiocarbon dates, no finds.
- Viking Period: one posthole with a radiocarbon date, no finds.
- Modern rubbish pits.
This phase is identified by a radiocarbon date and a collection of lithics, mainly knapped quartz with some leptite, ultramylonite and basalt, but no pottery and no flint. The only well-defined tool is a ground-surface asymmetrical basalt adze (F220) with a quasi-rectangular cross-section, found on the surface of the field during stripping. After separate first-hand study, Stone Age specialists Fredrik Molin and Roger Wikell unanimously placed the assemblage in the Late Mesolithic (5500-4000 cal BC), noting that the adze would look entirely at home among the abundant finds from the StrandvÃ¤gen settlement site in Motala (cf. Tom Carlsson 2008, Where the River Bends, pp. 232-245, 374-379). This date is consistent with the level above the sea and the absence of Neolithic pottery. None of the finds can certainly be determined as shore-abraded after knapping.
Most of the Stone Age finds occurred singly in the fills of sunken features that looked no different than usual. Only pits 124, 128 and 154 yielded more than one piece of knapped stone each, suggesting that they may have been Stone Age features. Radiocarbon-dating 128 and 154 would have been problematic as both showed signs of modern disturbance. This left only 124, but it yielded no charcoal. Hearth 45 however, which contained no other artefacts, yielded charcoal of rotten oakwood that was dated to 4460-4340 cal BC with 95% probability (Ua-37499, 5560Â±40 BP).
We found raw material in the form of unmodified quartz seashore pebbles in some features and collected them when they co-occurred with knapped stone. They are very unlike the typical gravel mixed in the fills and natural on site. In several cases, very small quartz pebbles have been used for knapping or simply broken open and then discarded.
In an appendix, Fredrik Molin analyses the lithics and summarises his impressions as follows (and I translate):
"The adze, the signs of micro-blade production, and possibly the use of leptite and ultramylonite all suggest a Late Mesolithic date. Nothing however excludes an Early Neolithic date except the absence of pottery.
Most of the quartz cannot be dated. But to my mind it appears too coarsely knapped for the Early or Middle Mesolithic - and such a date can be ruled out anyway because of shoreline displacement. Quartz knapping [in ÃstergÃ¶tland] becomes progressively coarser and uglier with time."
Feature 123, whose functional interpretation as a hearth was uncertain, yielded hazel charcoal that was dated to 2460-2270 cal BC at 79% probability (Ua-37500, 3855Â±35 BP). The interval straddles the Middle/Late Neolithic period shift at 2350 cal BC. A shore site from this era might be expected to yield some Late Pitted Ware decorated pottery, of which we found none. Fredrik Svanberg (web log comment, 20 March 2009) has suggested that the sample may have been contaminated, possibly combining material from the site's Mesolithic and Iron Age components.
Mid-1st Millennium AD
The Early Vendel Period, the later 6th century, is the site's heyday in terms of the metal detector finds. We made no datable finds of this era during the excavations. Two sherds of black coarse svartgods pottery are most parsimoniously allocated to this phase, though they may well be somewhat earlier or later. Pit 170 and hearth 135 yielded one radiocarbon date each, 170 on spruce-trunk charcoal in 320-440 cal AD (86% probability) and 135 on maple charcoal in 410-550 cal AD (95% probability). As none of the samples had a confirmed low intrinsic age, and as the site has not yielded a single piece of metalwork dating before the Migration Period, it seems safe to place the beginning of this activity phase in the 5th century AD. All pits and hearths on site that yielded no dating evidence are most parsimoniously placed here.
The excavated surface yielded several datable pieces of metalwork from the ploughsoil but none from the sunken features, and there were no remains of building foundations. This suggests that in the 6th century, this particular part of the site saw some metalworking carried out in flimsy structures or outdoors. Any refuse pits and postholes resulting from this activity were apparently less deep than the modern ploughing.
After an apparent hiatus of a century or more in the Late Vendel Period, there are at least six metal detector finds that can be dated to the Viking Period, AD 790-1100. This phase also shows up in a radiocarbon date from one of the excavation's few postholes, feature 8, where charcoal of rotten Scots pine was dated to 760-900 cal AD at 81% probability (Ua-37498, 1205Â±35 BP).
Modern Rubbish Pits
This phase gathers sunken features yielding modern artefacts, well-preserved bone (as soil conditions were very poor for such preservation), dynamited rock and/or a curious fine white sand. For unknown reasons, the sand had apparently been carted to site and used to fill four pits, two of which also contained modern finds. The artefact types found in the modern features were iron nails, iron wire, glass, pottery/china, roof tile, brick, fired clay and fresh wood. Modern activities that these features document are the burial of waste, the digging of a drainage ditch and the dynamiting of a few large boulders.