North American Archaeomagnetism
Archaeomagnetic Dating Services at the Illinois State Museum
In an effort to increase the number of proficient archaeomagnetic-sample collectors, different labs periodically offer training and
certification sessions. In these workshops, individuals become familiar with the theory behind archaeomagnetic dating and learn how
to collect archaeomagnetic samples in a number of different field situations. The goal of these workshops is to produce collectors
who not only know how to correctly collect archaeomagnetic samples, but are also able to judge when this technique will be appropriate
within the scope of the archaeological project.
Although sample collection is not difficult, it does take practice. Researchers should
always be trained by a knowledgeable collector before attempting to take samples on their own. An overview of the methodology is provided
on this website to acquaint researchers with the steps that are involved. An indepth tutorial can be found in the 1980 NPS publication
by Jeff Eighmy - "Archaeomagnetism: A Handbook for the Archaeologist."
Collecting workshop held in Payson, AZ in September 2002 in conjunction with Desert Archaeology and Tonto National Forest.
Training SEAC employees to collect archaeomagnetic samples from a mound at Shiloh National Military Park in June 2002.
Experience has shown that even the best collectors don't always fill out the sample field forms correctly. Below is an example of the types of information that should be included on the field forms sent to the lab. You can download and print a copy of the example by clicking on the figure.
It's usually a good idea to double check your original compass reading
Record comments for each specimen, such as the presence or absence of plaster, whether it wobbled during collection, etc. This is also a good place to record sun compass readings, if they were taken.
A good sketch map of the sampled feature should show the location of each specimen with respect to cracks and erosion, as well as an arrow indicating the direction of the specimen's compass reading
Refer to the scale on the cheat sheet if you're unsure of how to rate these parameters
Sample ID is the field number used to label the cubes. Common practice is to designate the site from digits in the site number, followed by the sequential sample number -first, second, third, etc. from the site.
A good description of the sample (matrix, oxidation, erosion, etc.) is very helpful in the lab
Geographic coordinates for the site (UTMs or lat/long) are crucial for data analysis.