The chronology of the peat profile was established by [.sup.14]C AMS dating (12 samples of Sphagnum stems), spheroidal carbonaceous particles, radionuclide dating using naturally occurring [.sup.210]Pb and tephrochronology
. A chronology of the peat sequence was produced by using Bayesian age-depth modelling software Bacon 2.2 (Blaauw & Christen 2011).
800 by the use of tephrochronology
(using layers of volcanic ash in the soil), before arguing that woodland clearance occurred at Seljaland during the early to mid-ninth century, more than a generation before the first Norse settlers arrived in the area.
To accurately date the specimens older than 50000 years, we must turn to other dating techniques such as uranium-series, or specimens must be found in situ and the sediments dated by tephrochronology
or some form of optically stimulated luminescence.
In spite of some pitfalls and problems, tephrochronology
is one of the few geochronological methods that offer a temporal and spatial precision to link and date geological, palaeoecological, palaeoclimatic, or archaeological sequences or events .
Research in the inland regions of New Britain has capitalised on an excellent volcanic tephrochronology
that provides relative dating for buried deposits across a large region (e.g.
Samples for paleomagnetic analysis, sedimentary analysis, tephrochronology
, and palynology were exported to the US for analysis.
A 0.5 kg sample was shipped to the United States Geological Survey (USGS) Tephrochronology
Laboratory at Menlo Park, California.
The radiocarbon dating of several palaeochannels is problematic and, consequently, a relative chronology was established on the basis of the site tephrochronology
. Older and younger than anticipated AMS and radiocarbon dates were obtained for some palaeochannels, whereas the dating of channels 107 and 109 accords with their tephrochronological identifications.
Although now tephrochronology
is used successfully in Quaternary geology and archaeology, identification of coeval ash beds in the Palaeozoic rocks appears to be more complicated.
Newnham RM, de Lange PJ, Lowe DJ (1995) Holocene vegetation, climate, and history of a raised bog complex, northern New Zealand, based on palynology, plant macrofossils, and tephrochronology
. The Holocene 5, 81-96.
Snowball presented an original talk about validating varve chronologies with independent complementary dating techniques (historically dated marker layers, palaeomagnetic secular variations, tephrochronology
, atmospheric lead pollution isochrones and radiocarbon wiggle matching) to reduce chronological uncertainties.