Magnetic Studies of Natural Goethite Samples from Tharsis, Huelva, Spain

CHAPARRO, M.A.E.; SINITO, A.M.; BIDEGAIN, J.C.; DE BARRIO, R.E.

GEOFíSICA INTERNACIONAL

INST GEOPHYSICS UNAM

Año: 2006 vol. 45 p. 219 - 230

0016-7169

Magnetic properties of goethite have not been widely studied. Natural samples often contain complex mineral mixtures. Material from Tharsis (Huelva, Spain) is studied in order to corroborate the presence of goethite using rock magnetic measurements. Measurements of magnetic susceptibility, isothermal remanent magnetisation (IRM), anhysteric remanent magnetisation (ARM), and magnetic and thermal demagnetisation were carried out. X-ray diffraction and scanning electron microscopy were also carried out. The results are discussed and compared with previous studies of synthetic and natural goethites. The presence of magnetically harder hematite was observed from IRM, thermal and non-magnetic studies.