2:45 PM - 3:00 PM
[SGL30-04] Attempt to date zircon by alpha recoil track observation
Keywords:zircon, alpha recoil track, step etching
We observed zircon with known age after chemical etching with atomic force microscope and measured the dimension (depth and diameter) of ART and counted the number of ARTs. The size of ART became enlarged through stepwise etching, and its behavior revealed that the diameter of ART is enlarged first and followed by the depth deepening. The depth and diameter shows linear relationship, but the slop on depth-diameter plot seems to be different among samples. When ages were calculated based on the number of tracks and measured U and Th concentrations, the order of ages is consistent with reference ages, but not identical. Further researches on etching and counting criteria are necessary to understand ART behavior in zircon.