Archaeomagnetism, the application of paleomagnetic methods to archaeological materials, is interdisciplinary not only in its methods but also in its impact. Well-dated archaeological materials are a critical data source for geomagnetic secular variation models [1–6], which are used to explore the dynamic structure of Earth’s core [7, 8], the rates of cosmogenic isotope production in the atmosphere [9–11] and the possible effect of geomagnetism on climate [11–13]. Precise documentation of the ancient field also helps contextualize geomagnetic observations from the modern era, such as the evolution of the South Atlantic Anomaly [14, 15] and the ongoing decline in the field’s intensity [16–18].