Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4678253 | Earth and Planetary Science Letters | 2010 | 12 Pages |
Abstract
The dearth of archaeomagnetic intensity data from the southern hemisphere is a limiting factor in evaluating models of global geomagnetic field evolution during the Holocene. Here we present high quality microwave archaeointensity data obtained from 34 ceramic fragments (21 archaeological contexts) from the Duke of York Islands, Fiji and Vanuatu, SW Pacific. Complementary Thellier-type experiments, corrected for anisotropy give good agreement with the microwave results. The majority of the new data prior to 250Â AD exhibit significantly lower intensity than predicted by current global field models (CALS3k.3 and ARCH3k) for the region, with an apparent intensity minimum at 250Â BC reaching as low as 50% of the present-day field strength. Between 400Â AD and 1500Â AD, the data are broadly consistent with the global field models but with a 20% higher field between 1200 and 1400Â AD. These new results therefore imply that the geomagnetic field has a greater range of variability than predicted and that further data from the region are essential to better constrain the global field models. The results also demonstrate that establishing an archaeomagnetic reference curve for dating SW Pacific ceramic artefacts is feasible, which has potentially significant implications for Pacific archaeological research.
Keywords
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Earth and Planetary Sciences (General)
Authors
Florian Stark, John Cassidy, Mimi J. Hill, John Shaw, Peter Sheppard,