A CASE STUDY OF THE INTERNAL STRUCTURES OF GOSSANS AND WEATHERING PROCESSES IN THE IBERIAN PYRITE BELT USING MAGNETIC FABRICS AND PALEOMAGNETIC DATING

of massive sulphide bodies form iron caps, i.e. true gossans and their subsequent alteration and re-sedimentation has resulted in iron terraces, i.e. displaced gossans. To study the stucture and evolution of both types of gossans, magnetic investigations have been carried out with two foci: (i) the characterisation and spatial distribution of magnetic fabrics in different mineralised settings, including massive sulphides, gossans and terraces, and (ii) paleomagnetic dating. Hematite has been identified as the suceptibility carrier in all sites and magnetic fabric investigation of four gossans reveals a vertical variation from top to in s