关键词: 磷灰石, 裂变径迹, 活断层

Abstract: After sampling and ore-dressing of the NNE fracture zone in the Jinshanbang granitic batholith in Suzhou, as well as chemical etching and neutron radiation of its heavymineral——apatite, we observed and statistically analysed its spontaneous and inducedfission track by means of white mica external probe. Our conclusions are as following:1) the fission track dating of samples No. 1, 2, 3 and 4 are 1.724±0.077×10⁸ -2.12 ± 0.076× 10⁸ years and mostly 1.724 ± 0.077 × 10⁸-1.88 ± 0.038× 10⁸ years, showing that the granitic batholith intruded in Jurassic-Cretaceous period;2) the fission track year of sample No.5 is 0.1920± 0.013× 10⁸ years, indicating that the geological event of the fault-breaking trace was in Miocene. In combination with historical earthquake and other geological information, we suggest that the earth's crust in this area has been relatively active in recent period; and3) it looks promising to apply the fission track method to active fault dating.

Key words: Apatite, Fission track, Active fault