Laboratory Modeling of the Archaeomagnetic Record in Thellier–Coe Experiments

Abstract—The influence of the magnitude of a laboratory magnetic field in the Thellier–Coe method on the results of determining the archaeointensity of the magnetic field was studied. The experiments were carried out on the same samples of artificial Neolithic ceramics and medieval bricks from Veliko Tarnovo city in laboratory magnetic fields of 20, 35, 50, 75, and 100 μT. The results show that for the studied samples, the magnitude of magnetic field induction determined in the Thellier–Coe experiments (archaeointensity) depends on the magnitude of the laboratory magnetic field induction in the Thellier–Coe method (which increases approximately according to a quasi-logarithmic law). It is suggested that the reason for the obtained dependence is the nonlinear dependence of the thermoremanent magnetization on the magnitude of the magnetic field (in the range of 20–100 μT) in which it was created.