Modified (Day et al.1977) plot with single domain (SD) to multidomain (MD) mixing curves for magnetite (TM0) from Dunlop (2002). Hysteresis parameters calculated for some example locations using ‘Advanced querying options’ with no geographic or age constraints. Orphan Knoll (IODP Sites U1302-U1303; Channell et al. 2012), Lake Baikal (Peck et al. 1994), Birkat Ram (Israel; Frank et al. 2003), Central North Atlantic (IODP Site U1308; Channell et al. 2008), Ein Feshka (Dead Sea; Frank et al. 2007), Grandfather Lake (Alaska; Geiss and Banerjee 2003), Irminger Basin (ODP Site 919; Channell 2006), and Lago di Mezzano (Italy; Frank 1999). n is the number of data.