摘要
The damage in zircon structure is caused by α-decay which is associated with radiation of uranium and thorium in zircon. Over the narrow dose range from 0.3×10<sup>16</sup> to 0.8×10<sup>16</sup> α-events mg<sup>-1</sup>, natural crystalline zircon begins to convert to metamict state. When α-decay dose reaches 0.8×10<sup>16</sup> α-events mg<sup>-1</sup>, the crystalline zircon would be changed to completely metamict state through several million geological years, and the metamict state zircon ap-
基金
Project supported by the National Natural Science Foundation of China.
