Associate Professor at Liverpool, Andy Herries, focuses on dating Hominid sites in South Africa by dating speolotherms (speolotherms are also known as flow stones and are created through the deposition of carbonate through time.
Stalactites and stalagmites form in the same way.) see
Small samples of soil or burnt building materials are prepared in situ by having small plastic discs glued to the surface of the layer.
The discs are marked with a line which points towards the present position of the magnetic pole - which is measured with a highly accurate compass.
This can include everything from hearths, fireplaces and kilns through to tiles, bricks and pottery.
Basically anything that has been subjected to heat at some point, either deliberately (e.g. if a fire burns down a building, its foundations and walls become suitable for archaeomagnetic study as a consequence).
Archaeomagnetic dating relies on the measuring the orientation of iron particles in burnt deposits towards the magnetic pole.
The pole moves around, but magnetised deposits stay fixed on its position at the time of burning.
For regular readers of this blog, the term “archaeomagnetism” will have been seen a number of times, most frequently in posts by me or Andy Herries!
Archaeomagnetism is the study of burnt material found on archaeological sites.
Sources for the term include the references listed on the front page of the Dictionary, and the websites listed in the sidebar.
This glossary entry is part of the Dictionary of Archaeology.
Then the discs and the small blocks of soil attached beneath them are carefully removed.