Ar is the basis of a common strategy for relationship rocks. The traditional K-Ar dating approach depends upon the belief that the rocks contained no argon at some time of formation and that each one the subsequent radiogenic argon (40Dung d?ch ???c b?m t? m?t b? ch?a ??n ??u cao h?n c?a các ?ng tr?ng cây, và sau khi dung d?ch ch?y qua h?t chi?u