Rock-magnetism data of the Erguita sediments. (a) Group 1 corresponding to single-domain to pseudo-single-domain magnetite. (b) Group 2 corresponding to superparamagnetic magnetite. (c) Group 3 corresponding to a mixture of iron oxides and iron oxyhydroxide minerals. Left panel, ZFC (zero field cooled) curve with the apparent Verwey transition (Tv); middle panel, mass-normalized RT-SIRM cycles, warming (in red) and cooling (in blue); right panel, uncorrected (orange) and corrected (blue) hysteresis loops.