Exploration of Buried SMS Deposits with Time Domain EM

Over the past year there has been a considerable economical and political interest in the potential use of marine mineral resources. One major field of investigation is the exploration of seafloor massive sulfides (SMS) deposits, which have high grades of metals. The search for SMS deposits is limited by the available technology to the detection of actively forming sites. Next to nothing is known about inactive sites, which from an economical standpoint should be the most promising. During research cruise on RV Poseidon, April 2015 we investigated an inactive SMS deposit at the Palinuro Seamount, Tyrrhenian Sea. Previous drillings had documented the presence of sediment buried SMS (Petersen et al., Economic Geology, 2014). Investigations were carried out with our new marine TEM induction system (MARTEMIS). Measurements show significantly increased amplitudes at some locations indicative for an increased conductivity of the seafloor. The associated locations coincide and further extend the area where SMS were found in drillings. Thus, it seems evident that the area of mineralization is larger than previously detected and our results can serve as proof of principle in the – to our knowledge – first successful experiment, which has used the TEM method to detect a buried SMS deposit.