Three representative vector endpoint diagrams: (A) sample from a clay-rich layer, exhibiting normal polarity; (B) sample from a clay-rich layer, exhibiting reverse polarity, with the separation of the stable remanence after removal of the normal viscous overprint; (C) instable remanence of a sample from a diatomaceous layer, characterised by a low S-ratio, indicative of reductive magnetite dissolution: see text for details. Axis labelling is in mA m−1.