non-invasive dendrochronology success and limitations
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Non-invasive dendrochronologysuccess and limitationsAoife Daly
Larvik Boats, Norway
Sampling for
dendrochronological
analysis
StegeborgDenmark
Sampling for dendrochronological analysis
Rembrandt’s ‘Entombment’(Hunterian Glasgow)
Photographing the end-grain
for dendrochronological
analysis
Oak anatomy
Gokstad projectPrevious analysis
• The building of the grave chamber in the Gokstad burial mound was estimated to be AD 900-905.
• The felling date for the trees used for the Gokstad Ship was estimated to 890s. No sapwood on the analysed samples.
• The wood for chamber and ship had grown in the Oslo fjord region (Bonde 1995).
DendroCT – Gokstadfunded by Nordic Culture Fund and Anders Jahre’s Humanitarian Foundation.
• Jan Bill, Oslo University
• Aoife Daly, Dendro.dk
• Øistein Johnson, Norwegian Geotechnical Institute
• Knut Dalen, Norwegian University of Life Sciences
Oseberg samples 6narrow ring series
Oseberg sample 6, images
Medical CT
The cut surface
Oseberg sample 6, first attempt
AD653 AD807
Oseberg\Z037003A.D
Oseberg\Z037003X.D
Oseberg sample 6, 2nd scanning
Micro CT
The cut surface
Oseberg, comparing tree-ring curves
AD653 AD807
Oseberg sample 6 from micro-CT Z037003a
Oseberg sample 6 conventional measurements Z037003d
Oseberg, comparing tree-ring curves
AD653 AD807
Oseberg sample 6 from micro-CT Z037003a
Oseberg sample 6 conventional measurements Z037003d
Direct versus scan
DIRECT MEASUREMENT Gokstad z038001a.d
MEASUREMENT FROM SCAN Gokstad z038001w.d
Direct versus scan
DIRECT MEASUREMENT Gokstad z038001a.d
MEASUREMENT FROM SCAN Gokstad z038001w.d
Method (see Bill et al 2012)
Spades from the Tune burial mound
method
0.34mm
Spades from Oseberg, Gokstad and Tune (Bill & Daly 2012)
(Photo Bill et al 2012)
Sapwood on the scanned images
Gokstad ship,
plank fragment
Gokstad Ship, dating(Daly, in press)
Gokstad ship
bord Z038027a after AD 744Z038014a after AD 796
z038005a after AD 838Z038015a after AD 844
Z038031a after AD 847Z038012a after AD 875
Z038029a after AD 877
z038006a after AD 884
bord tree2 Z038016a after AD 845z038002a after AD 845z038003a after AD 845z038008a after AD 845
bord tree6 Z038026a after AD 864z038004a&b after AD 864
Z038901a after AD 864z038007a after AD 864
bord tree8 Z038033a AD 878-92Z038010a AD 878-92Z038011a AD 878-92
q102q033
prøve 13028
068002
v
bord tree1 Z038009a after AD 884q027prøve 23
q097prøve 21prøve 22q096
q071prøve 18
069prøve 12
029001b001a
700500 600 800 900 1000
Gokstad Ship 885-892 Bed etc. winter 895-6
tværbjælke Z038023a after AD 884C10384.l
Gokstad boat G3 provenance? (Daly, in press)
Gokstad båd G3
1000
G3 bord Z038109a after AD 677Z0381138 after AD 752
Z038107a after AD 811Z038115a after AD 827
Z038112a after AD 852Z038111b after AD 864
G3 bord tree11 z038104a AD 887-896z038101a AD 887-896
G3 bord tree12 Z0381109 after AD 780z0381051 after AD 780
G3 bord tree13 Z038114a after AD 741Z038108a after AD 741
G3 7aG3-174
G3 199bG3 1kort
G3 18G3 17
G3-34G 3-15
G3 97aG3-8
G3 1langG3-1kort
800600 900700500
z038102a AD 889-900G 3-83G3 reparation?
Gokstad Ship 885-892 Bed etc. winter 895-6
Photos from http://www.vikingeskibsmuseet.dk/en/boatyard/previous-building-projects/the-small-boat-from-gokstad/
Gokstad, boat G3
Building
phase
Repair
Filenames - - z0381m03 z038102a
- start Dates AD 504 AD 575
- dates End AD 886 AD 888
Z037M001 AD 549 AD 815 12,55 - Oseberg ship (Daly unpubl.)
Z0382M01 AD 548 AD 895 4,70 11,51 Gokstad inventory big group (Daly 2011b)
Indbrudslag gr3 AD 550 AD 925 - 7,56 Break-in group 3 (Daly 2011a)
Z0371M01 AD 536 AD 833 - 5,99 Oseberg grave chamber (Daly upubl.)
N054M001 AD 666 AD 967 3,73 5,76 Klåstad (Eriksen 1993)
Z038ship AD 578 AD 876 3,64 5,72 Gokstad Ship (Daly 2011b)
Z055M001 AD 716 AD 889 - 5,27 Tune ship (Daly upubl.)
KAUPANG AD 518 AD 862 4,89 4,73 Kaupang (Bonde 2007)
The timbers used to build boat G3 from the Gokstad burial are dating with tree-ring curves from the
Oseberg Ship. The Oseberg ship is made from oaks that grew in West Norway (Bonde & Stylegar 2009)
so we can conclude that the small Boat G3 also comes from West Norway. A single plank from G3
however dates with tree-ring data from the region around Oslo Fjord (Daly, in press).
Identifying bark edge on the scanned images
Gokstat inventory,
bedpost fragment
Gokstad ship,
bedpost fragment
Bedpost bark edge
Bed etc.
winter 895-6
Bed post from Gokstad.
Many of the wooden
objects from Gokstad can
only be dated
dendrochronologically
thanks to the development
of a non-destructive
sampling method.
The plundering (Bill & Daly 2012)
The Break-in, all mounds
AD 750 AD 600 AD 900
Gokstad spade Z038836a træ 3 AD 895-6 Z038834a after AD 824
Z038833a after AD 868 Z038837a after AD 912
Z038835a after AD 939
Oseberg stretcher Z037216A after AD 898 Z037207A after AD 938 Z037208A after AD 944 z0372069 after AD 951 Z037209A after AD 953
Oseberg spade
Z037214A after AD 831 Z037210A after AD 839
z0372049 after AD 840 z037205a after AD 845
Z0372139 after AD 921 Z0372118 after AD 933
Tune spade Z055201A AD 895-909 Z055202x AD 903-17
C10421.e C10421b
C10421d C10421.f
C10421.h
C55000 6 1904-13 1904-13 1904-13a 1904-13c
Z037212A after AD 801 1904-21 Z0372159 AD 803-14 1904-308
1903-10 1904-48
1903-11 1904-50
1903-9 1904-75
C23838 o C23838 o
Oseberg grave chamber summer 834
Gokstad Ship 878-892
Tune c. 910 Gokstad bed etc. winter 895-6
Fig 1. De norske vikingeskibsgrave, dendrokronologisk datering af spaderne og båredele fra Oseberg, Gokstad og Tune
gravhøje.
**
**
The plunderings, correlation (Daly 2011a)
Filenames - - all Long
Group 3
Shorter
Group 2
- start Dates AD 550 AD 550 AD 766
- dates End AD 945 AD 925 AD 945
Z0382M01 AD 548 AD 895 19,98 13,93 9,61 Gokstad inventar big group (Daly
2011b)
oslo fjord AD 536 AD 967 17,67 15,00 9,17 oslo fjord (Gokstad skib, Oseberg
gravkammer, Tune skib, Klåstad skib)
(Daly upubl.)
Z0371M01 AD 536 AD 833 11,42 12,13 6,02 oseberg gravkammer (Daly upubl.)
Z055M001 AD 716 AD 889 11,13 7,60 9,94 Tune ship (Daly upubl.)
00695M01 AD 674 AD 997 9.46 6.85 7.52 Roskilde vrag 6 (Bonde 1997)
KAUPANG AD 518 AD 862 8,88 7,66 6,38 Kaupang (Bonde 2007, 282)
Z036M001 AD 666 AD 967 8,29 7,35 6,77 Klåstad (Daly upubl.)
N054M001 AD 666 AD 967 8,13 6,92 6,75 Klåstad (Eriksen 1993)
Z038ship AD 578 AD 876 7,39 7,59 9,26 Gokstad ship (Daly 2011b)
Z0382M02 AD 713 AD 876 5,59 4,96 4,04 Gokstad inventar small grp. (Daly
2011b)
9M456781 109 BC AD 1986 3,68 5,02 3,53 Jylland/Fyn (Nationalmuseet)
Z037M001 AD 549 AD 815 3,60 - 3,42 Oseberg ship (Daly upubl.)
Tabel 2. De norske vikingeskibsgrave, synkroniseringen mellem middelkurverne for spaderne og båredele fra Oseberg, Gokstad og Tune
gravhøje og diverse kurver fra Nordeuropa. Kilden til kurverne er givet .
The plundering, t-values (Bill & Daly 2012)
**
Gokstad spade Z038837a
Oseberg stretcher plank Z037216A
Modern oaks around Oslo Fjord(tree-ring data Kjeld Christensen, pers comm)
The plundering (Bill & Daly 2012)
The Break-in, all mounds
AD 750 AD 600 AD 900
Gokstad spade Z038836a træ 3 AD 895-6 Z038834a after AD 824
Z038833a after AD 868 Z038837a after AD 912
Z038835a after AD 939
Oseberg stretcher Z037216A after AD 898 Z037207A after AD 938 Z037208A after AD 944 z0372069 after AD 951 Z037209A after AD 953
Oseberg spade
Z037214A after AD 831 Z037210A after AD 839
z0372049 after AD 840 z037205a after AD 845
Z0372139 after AD 921 Z0372118 after AD 933
Tune spade Z055201A AD 895-909 Z055202x AD 903-17
C10421.e C10421b
C10421d C10421.f
C10421.h
C55000 6 1904-13 1904-13 1904-13a 1904-13c
Z037212A after AD 801 1904-21 Z0372159 AD 803-14 1904-308
1903-10 1904-48
1903-11 1904-50
1903-9 1904-75
C23838 o C23838 o
Oseberg grave chamber summer 834
Gokstad Ship 878-892
Tune c. 910 Gokstad bed etc. winter 895-6
Fig 1. De norske vikingeskibsgrave, dendrokronologisk datering af spaderne og båredele fra Oseberg, Gokstad og Tune
gravhøje.
**
**
Power politics?
Ring fortress
& bridge
980s
TrelleborgTrelleborg
Borgeby
Fyrkat
Jelling
Aggersborg
Nonnebakken
Ravning Enge bridge
Oseberg
GokstadStorhaug
Grønhaug
the plundering
after 953
800 850 900 950
burial
834
Gokstad Jelling
960sship
878-92
bed
895-6
Boat G3
887-96
ship
820
OsebergGrønhaugStorhaug
1000750
779burial burial
790-95
ship
780
ship
771
“Harald King had these
stones made after Gorm
his father and after
Thyra his mother – that
Harald who won all
Denmark and Norway
and made the Danes
Christian”
Dating c. 960s
The Jelling Stone
Kvæfjord 1, Norway (with permission of KHM)
‘After the Black Death: Painting and Polychrome Sculpture in Norway, 1350‒1550’ Noëlle Streeton, Tine Frøysaker & Kristin Kausland
Kvæfjord 1 altarpiece (with permission of KHM)
Kvæfjord 1 altarpiece. Tool marks on the backing planks, probably made with a broad side axe.
Kvæfjord 1 altarpiece (with permission of KHM)
Kvæfjord 1 altarpiece (with permission of KHM)
In spite of the rough condition of the plank surface tree-ring measurement from the macro photographs was possible, allowing successful non-invasive dendrochronological analysis
Kvæfjord 1 altarpiece backing planks – correlation with a selection of tree-ring data (Daly 2014)
Filenames - - Z101M001
- start dates AD1317
- dates end AD1493
Art-historical tree-ring data, Southern Baltic region0M040004 AD1156 AD1597 9.56 Baltic 1 (Hillam & Tyers 1995)
SUTYPE14 AD1259 AD1516 8.30 London Sutton House panels (Tyers pers comm.)
BOWHILLB AD1161 AD1483 8.24 Exeter Bowhill ceiling boards (Tyers pers comm.)
H11EOM01 AD1260 AD1495 8.05 Bordesholmer Altar (Hamburg uni., revised Daly 2007)
Ship and barrel chronologies0075M001 AD1113 AD1463 7.10 Vejdyb ship 16 timber (Daly 1997)
literature• Bill, J. & Daly, A., 2012. The plundering of the ship graves from Oseberg and Gokstad – an example of power politics?
Antiquity, 86, 808-824.
• Bill, J., Dalen, K.S., Daly, A. og Johnsen, Ø., 2012. Dendro CT – dendrochronology without damage. Dendrochronologia 30
(2012) 223–230.
• Bonde, N. 1995. Dendrochronological dating of the Viking age ship burials at Oseberg, Gokstad and Tune, Norway. In: A.
Sinclair, E. Slater & J. Gowlett (Eds) Archaeological Sciences 1995. Oxford, 195-200.
• Bonde, N., 1997. Præliminær dendrokronologisk undersøgelse af seks skibsvrag fra Roskildes gamle havneområde.
Nationalmuseets Naturvidenskabelige Undersøgelser rapport 1997.15, Copenhagen.
• Bonde, N., 2007. Dendrochronological dates from Kaupang. In: Dagfinn Skre (ed.), Kaupang in Skiringssal, Kaupang
excavation project publication series volume 1. Aarhus University Press, 273-282.
• Bonde, N. and Stylegar, F.-A. (2009). Fra Avaldsnes til Oseberg. Dendrokronologiske undersøkelser av skipsgravene fra
Storhaug og Grønhaug på Karmøy. Viking, LXXII, 149-168.
• Daly, A., 1997. Dendrokronologisk undersøgelse af skibsvrag fra Vejdyb udfor Hals, Aalborg Amt. Nationalmuseets
Naturvidenskabelige Undersøgelser rapport 12, 1997, København.
• Daly, A., 2007. Timber, Trade and Tree-rings. A dendrochronological analysis of structural oak timber in Northern Europe, c.
AD 1000 to c. AD 1650. Ph.D. thesis submitted February 2007, University of Southern Denmark.
• Daly, A. 2011a. De norske vikingeskibsgrave, indbrudslag. Dendro.dk report 6:2011, Brønshøj.
• Report prepared for the Museum of Cultural History, Oslo.
• Daly, A. 2011b. De norske vikingeskibsgrave, Gokstad. Dendro.dk report 9:2011, Brønshøj. Report prepared for the Museum
of Cultural History, Oslo.
• Daly, A., 2014. Dendrochronological analysis of altarpiece, Kvæfjord 1, Norway (C3215). CATS dendro report 6.
• Daly, A., in press. ‘Exploring the Norwegian Viking ship burials through non-destructive dendrochronology’. In Jan Bill ed.
Returning to Gokstad: The art and the science of revisiting monumental burials in Scandinavia, Aarhus University Press.
• Eriksen, O.H., 1993. Dendrokronologisk undersøgelse af skibsvrag fra Klåstad, Norge. Nationalmuseets Naturvidenskabelige
Undersøgelser rapport 1993.1, Copenhagen.
• Hillam J. & Tyers I., 1995. Reliability and repeatability in dendrochronological analysis: tests using the Fletcher archive of
panel-painting data, Archaeometry 37, p. 395–405.
Conclusion and creditsMethods
Non-invasive dendrochronology and provenance determination – high tech to low tech.
But I’m not quite ready to sell my chain-saw yet! :o)
Credits
DendroCT – Jan Bill & Nordic Culture Fund and Anders Jahre’s Humanitarian Foundation.
‘After the Black Death: Painting and Polychrome Sculpture in Norway, 1350‒1550’ – Noëlle Streeton, Tine Frøysaker & Kristin Kausland, Department of Archaeology, Conservation and History (IAKH) and the Faculty of Humanities, UiO. http://www.hf.uio.no/iakh/english/research/projects/medieval-painting/index.html