text: Primitive meteorites have been studied using measurements of Δ47.  These analyses also assume that the primary isotopic signature of the sample has been lost.  In this case, measurements of Δ47 instead provide information on the high-temperature event that isotopically reset the sample.  Existing Δ47 analyses on primitive meteorites have been used to infer the duration and temperature of aqueous alteration events, as well as to estimate the isotopic composition of the alteration fluid.