Konkrecje Fe-Mn z polskiego sektora Morza Bałtyckiego : stan wiedzy i potrzeba badań

Studies on Baltic nodules have been undertaken since the1920s. In the 1970sand 1980s, the Polish Geological Institute - National Research Institute conducted researches on the bottom sediments of the Baltic Sea, which allowed identifying the regions of occurrence of Fe-Mn nodules in the southern part of the Baltic Sea (Mojski, 1989-1994). Nodules from the Polish Baltic Sea Zone are the least studied element of the marine environment. So far, there is a lack of information on environmental-geological conditions of formation and occurrence of nodules, their metal resources and deposit potential. The Fe-Mn nodules may be a valuable source of information on the contamination of the Baltic Sea water and bottom sediments. In cooperation between the Institute of Oceanography of the University ofGdañsk and the Polish Geological Institute-NRI, two research cruises were carried out in August and September 2020 on a 5 X 5 km testing ground in the Gotland-Gdańsk Threshold region. The seabed surface was profiled using multibeam echo sounders and a side-scan sonar. A hundred samples of Fe-Mn nodules, 25 samples of surface sediments associated with the nodules, and25 samples of clay rocks underlain by marine sediments were collected. The extensive documentary material will enable, for the first time, to estimate the nodule resources and determine the regularity of their occurrence.