Micro-scale magnetic grains from shallow water sediments of the Gulf of Gdańsk

Three cores recovered from the Gulf of Gdańsk in 2006 contain magnetic spherules of different origins. According to their chemical compositions and morphological features the magnetic grains were divided into two groups: (1) anthropogenic spherules primarily composed of SiO₂, Al₂O₃ and Fe₂O₃; (2) Fe-oxide spherules of extraterrestrial origin. These two groups are present in the surface sediments, indicating they are products of both man-made pollution and an influx of extraterrestrial matter. The presence of anthropogenic dust in the marine sediments is a record of pollution from nearby industrialized areas. On the basis of the presence of these spherules a tool could be developed for studying sedimentation rates in the marine sediments. However more precise studies are required to develop this method.