The geomagnetic field is a global feature with an important regional character. Its temporal and spatial variation can be observed from direct measurements such as satellites and logbook available since the 17th century. In order to know the behaviour of the geomagnetic field further in the past indirect measurements are needed. These indirect measurements (called paleo or archeomagnetic data) are based on the study of the remanent magnetization acquired by the iron oxides present in certain rocks and archaeological materials when heated at high temperatures (Néel, 1955).

This work was supported by two R&D&I projects, CERAC (HAR2016-75133-C3-1-P) led by V. Martínez and J.M. Gurt, and CONCERAC (HAR2016-75133-C3-3-P) led by E. Ariño, all funded by the Spanish Ministry of Science, Innovation and Universities. V. Martínez worked on this paper through the post-doctoral research contract Ramón y Cajal (RYC-2014-15789). M. Gómez-Paccard thanks to RYC-2013-14405. This congress was funded by Red de trabajo y laboratorios MAGIBERII (CGL2017-90632-REDT).

Reunión MAGIBER XI Portugal ,Condeixa a Nova (4 al 6 de septiembre de 2019)