Historic Archaeomagnetic Results from the Eastern U.S., and Comparison with Secular Variation Models

Archaeomagnetic data can supplement direct observations of the geomagnetic field in the development of high-resolution records of regional secular variation. Archaeomagnetic data from historic archaeological features are particularly well suited for this because of the highly accurate and precise dating afforded through historic documents and artifacts. Here, archaeomagnetic directional data from 20 well-dated historic archaeological features in the eastern U.S. are presented and compared to existing models of secular variation and historic field measurements to demonstrate the compatibility between archaeomagnetic and direct measurements of geomagnetic field directions. Then, a previously undated historic brick kiln from Virginia is archaeomagnetically dated to the late 17th-early 18th centuries by statistically comparing the kiln's archaeomagnetic data to existing secular variation models.