BORINGHOLM, SKANDERBORG AMT

Forhistorisk Museum Moesgård og Vejle Museum.
Indsendt af Jan Koch.
Undersøgt af Orla Hylleberg Eriksen.
NNU j.nr. A5885

Voldsted
18 prøver af Quercus sp., er undersøgt. 16 prøver er dateret. 14 af prøverne havde splintved bevaret, heraf 8 med fuld splint.

Prøverne kommer fra fire forskellige steder på borgområdet. "Bro", "Voldgrav", "Østhjørne af banke" og "Borg".

Bro
Fem prøver, hvoraf fire er dateret. Undersøgelsen viser at Broen formentlig repræsenterer den tidligste fase af anlægget. En af prøverne (60131079) har fuld splint bevaret og kommer fra et træ, som er fældet i vinterhalvåret 1367/68. To andre prøver hører sandsynligvis også til denne fase.
Den sidste prøve (60131089) må være fra en senere reparation. Yngste bevarede år er dannet i 1385. Kompenseres der for manglende splintved kan fældningstidspunktet for træet, der har leveret tømmer til prøven, beregnes til at ligge imellem 1386 og 1401.

"Borg"
To prøver, begge dateret og begge med splintved bevaret. De to kurver er sammenregnet til en middelkurve på 85 år. Yngste bevarede år dannet i 1370 (60131189). Træerne, der har leveret tømmer til prøverne, er fældet i ca. 1370 eller kort tid efter.

Voldgrav
Otte prøver, hvoraf syv er dateret. Seks af de daterede prøver har splint bevaret, heraf fem med fuld splint. Tre af prøverne er fældet forår/sommer 1380. På disse består den sidste årring kun af ganske få vårkar, hvilket indikerer at fældningen er sket tidligt i vækstsæsonen (april/maj). Derfor er det også nærliggende at antage, at de to prøver med færdigdannet barkring i 1379 også er fældet i det tidlige forår 1380, inden disse træer har nået at danne vårkar.

Østhjørne af banke
Tre prøver, alle dateret. Alle prøverne har splint bevaret, heraf to med fuld splint. Den ene kommer fra et træ, som er fældet i vinterhalvåret 1379/80 og den anden fra et træ, som er fældet i foråret/sommeren 1380. Også her vil det være rimeligt at antage at fældningen af begge træer, kan være sket tidligt i vækstsæsonen 1380.

Til dateringen af prøverne er der brugt referencekurver fra Danmark, Tyskland og Sydvestsverige

Splintstatistik: 15 -5/+10 år. (unge træer; under 100 år)

Katalog

English summary:

BORINGHOLM, SKANDERBORG AMT

Fort
18 samples of Quercus sp., oak, were examined. 16 samples are dated. 14 of the samples had sapwood preserved of which 8 had complete sapwood.

The samples comes from four sites within the fort.
The "bridge", the "moat", the "east corner of bank" and the "castle".

Bridge
Five samples, of which four are dated. The analysis shows that the bridge probably represents the oldest phase of the construction. One of the samples (60131079), which has complete sapwood preserved, comes from a tree which was felled in the winter AD 1367/68. Two other samples most likely belong to this phase.
The last sample (60131089) may come from a later repair. The outermost preserved tree-ring was formed in AD 1385. Allowing for missing sapwood, the estimated felling date, for the tree, from which the sample comes, lies within the period AD 1386-1401.

"Castle"
Two samples, both of which were dated and had sapwood preserved. The two curves are averaged to form a mean curve of 85 years. The outermost tree-ring was formed in 1370 (60131189). The felling date, for the trees, from which the samples come, is estimated to be c. AD 1370 or shortly after.

Moat
Eight samples, of which seven are dated. Six of the dated samples have sapwood preserved, of which five have complete sapwood. Three of the samples come from trees, which are felled in the spring/summer AD 1380. On these samples the outermost tree-ring consists of very few spring vessels, which indicates that the trees, from which they come, is felled early in the growing season (April/May). Therefore it can be suggested that the two other samples with complete sapwood preserved (outermost ring formed in 1379) come from trees, which were also felled in the early spring AD 1380, before the trees had developed spring vessels.

East corner of bank
Three samples, all are dated. All of the samples had sapwood preserved of which two had complete sapwood. The first comes from a tree which was felled in the winter AD 1379/80 and the other from a tree which was felled in spring/summer AD 1380. Here it is also reasonable to assume that the felling can have taken place early in the growing season AD 1380.

In dating the samples, reference chronologies are used from Denmark, Germany and south-west Sweden.

Sapwood statistic: 15 -5/+10 years. (young trees; under 100 years).

Back to report page