Partial self-reversal of TRM in baked soils and ceramics from Ecuador

Rock-magnetic signature of precipitation and extreme runoff events in south-eastern Patagonia since 51,200 cal BP from the sediments of Laguna Potrok Aike

“…The distinctive contribution of high coercivity minerals in rock-magnetic facies 2 (and the absence of iron sulfides such as greigite and pyrrhotite) hence suggests that pedogenic hematite and/or goethite could account for the observed GRM acquisition. In addition, a near anti-parallel orientation of the GRM in some of the facies 2 might also indicate grains prone to selfreversal as reported for oxidized iron oxides such as maghemite and ilmeno-hematite (Channell and Xuan, 2009;Roperch et al, 2012). If this is the case, the GRM acquired during AF demagnetization of the NRM and ARM must have been swamped by the strong normal component held by detrital magnetite and only detectable during AF demagnetization of the IRM because of fieldimpressed anisotropy.…”