A new three-axis vibrating sample magnetometer for continuous high-temperature magnetization measurements: applications to paleo- and archeo-intensity determinations

We have developed a new three-axis vibrating sample magnetometer, which allows continuous high-temperature magnetization measurements of individual cylindrical ∼0.75 cm3 samples up to ∼650 °C and the acquisition of thermoremanent magnetization (TRM) in any direction and field intensity up to 200 μT. We propose a fast (less than 2.5 h) automated experimental procedure adapted from Boydʹs [Nature 319 (1986) 208–209] modified version of the Thellier and Thellier [Ann. Geophys. 15 (1959) 285–376] method which provides continuous intensity determinations over a large (typically 300 °C) temperature interval for each sample. This procedure allows one to take into account both the cooling rate dependence of TRM acquisition and anisotropy of TRM. Several examples of analyses of ancient magnetization demonstrate the quality and reliability of the data and illustrate the promising potential of this new instrument in paleo- and archeomagnetism.