Geomagnetic excursions in the Brunhes Chron according to various authors. Column 1: Langereis et al. (1997):asterisks mark ‘well-dated, global’ excursions, others were deemed ‘restricted or not as certain’; column 2: Worm (1997);column 3: Lund et al. (2001a); column 4: well-documented excursions with acceptable age control (this study).