Fig. 3From: Characterization of marine ferromanganese crust from the Pacific using residues of selective chemical leaching: identification of fossil magnetotactic bacteria with FE-SEM and rock magnetic methodsSecondary electron images of extracted materials observed with FE-SEM; a chain of magnetic particles considered to be fossil biogenic magnetite, b icthyolith, c titanomagnetite with dendritic texture, d coccolith, e foraminifera, and f cosmic spherule. a–c, f are observed with 15 kV, whereas d, e were observed with 5 kV. Particles in a were extracted from Unit 1, and others from Unit 2. The identification of the origin of the grains was primarily based on morphologies with the help of chemical analyses using EDS for grains larger than ~ 10 µmBack to article page