Age Of Granite Rocks Can Be Determined Using Rb - Sr Whole Rock Radioactive Dating Method And The Following Age Equation, (87Sr/86Sr) = (87Sr/86Sr), + (87Rb/86Sr) (Ell - 1) For A Suite Of Representative Co-Magmatic Granitic Rocks, The Rb - Sr Whole Rock Isochron Plot And Relevant Data Are Shown In The Diagram. The Age Of Granite Is Calculated At ---------Ga

Sri 87 86 Age of granite rocks can be determined using Rb - Sr whole rock radioactive dating method and the following age equation, (87Sr/ 86 Sr) = (87 Sr/ 86 Sr), + (87Rb/86Sr) (e - 1) For a suite of representative co-magmatic granitic rocks, the Rb - Sr whole rock isochron plot and relevant data are shown in the diagram. The age of granite is calculated at ---- (1 Ga = 10 yrs, give answer in one decimal place). ----Ga Isochron Sr = 0.7004 tan@=0.014301 \=1.42 x 10"yr*1 87 Rb Sr