Developing Archaeomagnetic Dating for Neolithic Scotland
Studying the past geomagnetic field preserved in fired archaeological features such as hearths, furnaces, or kilns, allows dating of their last use and provides crucial information about the behaviour of the geodynamo. This thesis plays a vital role in expanding and developing the application of archaeomagnetic dating in the British Isles by studying fired archaeological material from Neolithic Scotland (4000 BCE – 2500 BCE). The aim was to use archaeomagnetic studies of fired archaeological material to define and better understand variations in the past geomagnetic field through the Scottish Neolithic. Six archaeological sites were extensively sampled producing 26 newly compiled archaeomagnetic directions from over 1200 samples for Neolithic Scotland. Particularly important are results from ongoing excavations at the Ness of Brodgar, situated at the Heart of Neolithic Orkney’s UNESCO World Heritage Site. This thesis integrates high resolution archaeomagnetic sampling of stratigraphically related material and a focussed radiocarbon dating programme (21 radiocarbon dates) alongside prior chronological information to define secular variation for a previously poorly defined time period. Additionally, 15 archaeomagnetic directions from prior work at the Ness of Brodgar are provided with independent dates bringing the total for the UK dataset to 41. This thesis implies rapid geomagnetic field change of more than 12° per century over 200 years around the 3rd millennium BCE challenging our previous understanding of secular variation. Archaeomagnetic analysis was conducted utilising AF demagnetisation in addition to the full suite of magnetic susceptibility measurements: low-frequency, high-frequency, and representative heating/cooling thermomagnetic curves as a proxy for understanding paleotemperatures.
Archaeomagnetic dating, Neolithic, Scotland, Orkney, Secular variation, Geomagnetic, Fired archaeological material
Networked Digital Library of Theses and Dissertations