archaeomagnetism

noun

ar·​chaeo·​mag·​ne·​tism ˌär-kē-(ˌ)ō-ˈmag-nə-ˌti-zəm 

variants or archeomagnetism

: the residual magnetism exhibited by archaeological remains that is used to determine their age and to help determine the former positions of the earth's magnetic poles

Archaeomagnetism (specifically, thermo-remanent magnetism) can also be used to date fired clay. Like [thermoluminescence], the principle is deceptively simple: the direction of the earth's magnetic field has changed over time, and magnetic particles contained in clay align with the direction that prevailed at the time of their last intense heating (typically, firing in a kiln).

—Kevin Greene, Interpreting the Past: Roman Pottery, 1992

archaeomagnetic adjective

or archeomagnetic

ˌär-kē-(ˌ)ō-mag-ˈne-tik 

It was decided to establish a solid calendrical base and to do this an eighteenth century … settlement was chosen for excavation. This decision was made as there was no dendrochronology, Carbon 14 or archaeomagnetic technology available at the time.

—Charles C. Di Peso, American Indian Art Magazine, Spring 1981

Word History

Etymology

archaeo- + magnetism

First Known Use

1958, in the meaning defined above

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