POSEIDON POS442

During cruise P442 we will investigate the geological setting of two known hydrothermal deposits (Palinuro and Panarea) in the Tyrrhenian Sea in high-resolution. This leg was shifted from a previous Poseidon cruise in the spring 2011 to 2012 because of the participation of the AUV “Abyss” in the search for the lost Air France flight AF447. The investigation of submarine hydrothermal systems in the Tyrrhenian Sea is aimed at a better understanding of the formation of metal deposits in island arcs where the shallow water depth (usually < 1000 m) and the influence of the subducting plate result in enrichments of gases, precious metals as well as abundant toxic elements (such as As, Hg, Pb, Sb, and Tl) at the seafloor. These enrichments make such sites interesting from an economic geology point of view, but also because of the geogene input of toxic metals into the environment. The use of GEOMARs autonomous underwater vehicle (AUV) “Abyss” will allow to answer questions related to the lateral and vertical extent of the partially sediment-covered mineralization as well as to the structural control of the venting and its associated faunal communities. High-resolution bathymetric, sidescan sonar, as well as photographic surveys will be performed. Additionally chemical sensors will be used to investigate the water column for signs of hydrothermal activity in areas not previously investigated. During the cruise a sediment-profiler on the AUV as well as a magnetometer will be tested for its potential to search for sediment-covered hydrothermal mineralization.