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

Abstract

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 SiO 2 , Al 2 O 3 and Fe 2 O 3 ; (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.

Implications from chemical, structural and mineralogical studies of magnetic microspherules from around the lower younger dryas boundary (new mexico, usa)

“…; Marini and Raukas ; Uscinowicz ). However, unlike the cosmic microspherules, the magnetic microspherules of the industrial origin are usually characterized by smooth, polished surfaces (no dendritic structures), and may often have grains of zircon (and other minerals) welded upon them (Marini and Raukas ; Uscinowicz ; Voldman et al . ).…”

“…Magnetic microspherules of industrial origin are the most difficult to distinguish from the cosmic microspherules (e.g. Vuorelainen and Törnroos 1986;Horng et al 2009;Marini and Raukas 2009;Uscinowicz 2009). However, unlike the cosmic microspherules, the magnetic microspherules of the industrial origin are usually characterized by smooth, polished surfaces (no dendritic structures), and may often have grains of zircon (and other minerals) welded upon them (Marini and Raukas 2009;Uscinowicz 2009;Voldman et al 2012).…”

Spherical, magnetic grains of extraterrestrial origin, isolated from Pacific sediments

“…Others, perhaps even the majority, arise from ablation of the surface of a meteorite when it passes through the atmosphere (Raukas 2004, Uścinowicz 2009). The chemical composition of these spherules come from the characteristics of the particular meteorite.…”

Cosmic spherules from the Ordovician of Argentina

“…coal-fired power plants, welding operations) usually exhibit perfectly spherical shapes with smooth, polished surfaces, and may have grains of zircon and other minerals welded upon them (e.g. see Puffer et al, 1980;Blaha et al, 2008;Uścinowicz, 2009). Typical contamination fly-ash spherules are comparatively poor in Fe but rich in Si, Al, and minor admixtures of other elements (Na, Ca, Mg, K) (Marvin and Einaudi, 1967;Shoumkova, 2011).…”