Exploring the potential of acquisition curves of the anhysteretic remanent magnetization as a tool to detect subtle magnetic alteration induced by heating

► Observed underestimated paleointensities are unexplained by phenomenological theory. ► ARM acquisition curves discriminate between thermochemical and magnetic alteration. ► An extended multispecimen paleointensity protocol is proposed. ► Paleointensity underestimates and approximately correct values can be discriminated.