 The analysis of relative concentrations of samarium and neodymium isotopes 147Sm , 144Nd , and 143Nd allows the determination of the age and origin of rocks and meteorites in samarium @-@ neodymium dating . Both elements are lanthanides and have very similar physical and chemical properties . Therefore , Sm @-@ Nd dating is either insensitive to partitioning of the marker elements during various geological processes , or such partitioning can well be understood and modeled from the ionic radii of the involved elements . 
