These minerals can be dated by radioactive decay techniques because of the very small quantities of radioactivetrace elements they, in turn, contain.
这些矿物可以用放射性衰变技术测定年代，因为它们所含的放射性微量元素非常少。
2
"Platinum" is a powerfully radioactivetrace element.
“铂”：非常有辐射力的微量元素。
3
A total of 485 zircons held inclusions, and about a dozen or so of these contained radioactivetrace elements that allowed the researchers to determine their ages.