Be and 26
Al in fluvial terrace samples that have been repeatedly buried and exposed to the evolution process are difficult to separate using conventional methods. Based on prior experiments, 10
Be in carbonate, iron-bearing mineral and 10
Be produced in the atmosphere were separated by manual hand picking, magnetic separator sorting and acid washing methods, improving the procedure of purifying the quartz samples. The results show that anion exchange column, with a length of 9 cm and inner diameter of 1cm, matched 4 mol/L hydrofluoric acid leachate, can effectively separate B, Mg, Ca, Cr, Fe, Mn, Ni, Ti and Mn. The recoveries of Be and Al are 95.7% and 85.7%, resepectively. Be and Al can be separated by ion exchange very well which have recoveries up to 85%. The procedure blanks are 2.19×10-15
Be and 26
Al, respectively which are comparable with other labs. The exposure ages of Chengdu Plain alluvial elements are 76.36±9.51 ka for 10
Be and 69.44±14.13 ka for 26
Al, which provides a chronological basis for evaluating the structural features and activities of buried faults in the front of the Longmenshan.