D E N D R O A R C H E O L O G Y

Photograph: Stones 55

To be present at the instance of the celebrated breakthrough in science that set the chronological house in order for the Southwestern United States was reward enough.“

”Emil Haury, 1962

Photograph: Sco! Catron

Aztec Ruin National Monument New Mexico

1ONETHE GHOST SHIP

THE ‘MARY CELESTE’

In December 1872, she was discovered at sea with all sail set and everything in order but not a person was on board or ever found.

“”Spicer, 1942

Sank o! Haiti, 1885

Detailed analysis of twelve samples of wood by Dr. David Etheridge, a wood scientist from Victoria, British Columbia, showed the ship was built either in Northern New England or the Maritime Provinces of Canada.

“

” NUMA.net

h!p://www.numa.net/press/080801.html

Longleaf pine Pinus palustris

Photograph: Chris M.

h!p://esp.cr.usgs.gov/data/atlas/li!le/

h!p://esp.cr.usgs.gov/data/atlas/li!le/

Longleaf pine chronologies

1820 - 18871852 - 1894

1836 - 1890

Crossdating suggests that these timbers were derived from trees cut in the vicinity of southwestern Georgia some time a!er 1894.

“”St. George 2001, Report to NUMA and Geomarine Associates

2TWORED RIVER SETTLEMENTS

Photograph: Greg Brooks

2008

1875

Photo: Erik Nielsen

Fort Du!erin 1873

Photo: Erik Nielsen

Photo: Erik Nielsen

‘Rat River’ House 1859

3THREETHE RETURN OF THE SEA STALLION

Roskilde

Skuldelev 2 30-m long, 3.8-m wide, 70 to 80-member crew

The most important limitation [of shipwreck archaeology]…is the virtual impossibility of deducing the shipyard where a vessel was built.

“”Basch, 1972

It was possible to correlate the tree-ring curves from twelve planks and the keel and construct a chronology that spanned 248 years, representing the building phase of the ship.

“”Bonde and Crumlin-Pederson, 1990

Roskilde

Source: Bonde and Crumlin-Pederson, 1990

The Skuldelev-chronology fi"ed perfectly with all the chronologies except the one for Belfast, which, as it turned out, did not cover the dating range for our curve.

“”Bonde and Crumlin-Pederson, 1990

Based on these results we can conclude that the longship excavated in Denmark was built in the region of the Irish Sea, most likely in Dublin, in the second half of the 11th century.

“”Bonde and Crumlin-Pederson, 1990

Roskilde

Dublin

Photograph: William Murphy

The result [of successful dendrochronological dating on ships] is o!en so precise that every recognized theory which conflicts with it is immediately discredited.

“”Bonde & Christensen 1982

M A N Y O T H E R A P P L I C A T I O N S

The Messiah-Salabue Stradivarius of 1716

Photograph: Henri Grissino-Mayer

Source: Friedrich et al., Radiocarbon, 2004

Source: Friedrich et al., Radiocarbon, 2004

‘Seahenge’ Trees felled in 2049 B.C.E.

Fluctuation in the amount of carbon dioxide in the atmosphere can also a#ect the concentration of 14C in the CO2.

“”University of Arizona AMS Laboratory

Source: Reimer et al., Radiocarbon, 2004

The Holocene part of the 14C calibration is based on several millennia-long tree-ring chronologies providing an annual, absolute time frame within the possible error of the dendrochronology, which was rigorously tested by internal replication of many overlapping sections.

“

”Reimer et al., Radiocarbon, 2004

Cu"ing datesDates assigned to crossdated wood or charcoal specimens that possess evidence that the last ring present on the specimen was the last ring grown by the tree before it died.

Source: Nash, Journal of Archeological Research, 2002

Photograph: Ron Towner

Photograph: Pearce Paul Creasman

Noncu"ing datesDates assigned to crossdated specimens if there is no evidence indicating that the last ring present on the specimen was the last one growth before the tree died.

Source: Nash, Journal of Archeological Research, 2002

Date clusteringIf a number of tree-ring dates from a given site cluster in one calendar year (or are very close together), one can infer that some substantial construction (or repair) occurred at that time.

Source: Nash, Journal of Archeological Research, 2002

ReadingNash (2002) Archaeological tree-ring dating at the millennium. Journal of Archeological Research 3, 243-275.

NO CLASSApril 12 and April 14

ReadingSto!el and Bollschweiler (2008), Tree-ring analysis in natural hazards research – an overview. Natural Hazards and Earth Systems Science 8, 187-202.

ReadingSto!el et al. (2010), Whither Dendrogeomorphology? In Sto!el et al., (eds.), Tree Rings and Natural Hazards.