Two reference materials, trachytes MDO-G and ISH-G, for argon dating (K-Ar and $^{40}$Ar/$^{39}$Ar) of Pleistocene and Holocene rocks

International audienceWith the recent extension of K-Ar dating methods within the Upper Pleistocene time, the use of new standards is recommended to allow calibration and inter-laboratory comparisons. For this purpose, two pure microliticgroundmass reference materials were prepared from trachy-basaltic lavas: Trachyte (MDO-G) from Mont Dore, Puy de Sancy, Massif Central is around 250 000 years old; the second Trachyte (ISH-G) from the Isle ofIschia. Gulf of Naples (Italy), is historical: Arso flow erupted on Christmas 1301 - January 1302 AD