Geochemistry of sediment cores during SONNE cruises SO242/1 and SO242/2 at the DISCOL area, Peru Basin

The DISCOL area represents a part of the deep sea that is extensively covered with manganese nodules and represents a unique study area, where in 1989 a circular area with a diameter of about 2 nautical miles was intensely disturbed with a plough-harrow. The presented data was collected during the two legs of the SO242 research cruise in 2015 with the aim to better understand the ecological impacts of deep-sea seafloor disturbances (e.g. through nodule mining operations).

Several devices were deployed at each sampling site to retrieve surface and subsurface sediment samples: (i) a Oktopus multiple-corer (MUC), which samples the upper 20 – 40 cm of the sediment including the overlying bottom water; The corer was equipped with a TV-Camera system for precise positioning, e.g. for sampling specific seafloor features like the disturbance tracks; (ii) a ROV-deployed push-corer (PUC) focusing on small-scale topographic features created by the seafloor disturbance; (iii) a box-corer (BC - USNEL Spade Corer) to sample the sediment inclusive macrofauna as well as associated nodules; and (iv) a gravity-corer (GC) extracting sediment up to 10 mbsf.