利用磷灰石裂变径迹约束脆性断裂活动的时限

A case of application using apatite fission track to restrict the time of brittle fault movement

本文通过鲁西隆起区、沂沭断裂带不同性质断裂构造解析,并对其构造带及构造带两侧未变形地层进行野外样品采集、测试、分析的实例总结,认为利用磷灰石裂变径迹低温测年技术,辅助以样品磷灰石裂变径迹冷却史模拟分析,可以直接对地质体不同性质断裂活动的时间进行约束.鉴于磷灰石裂变径迹对低温特殊的敏感性与反映温度区间的局限性,利用该方法约束断裂时限时,需注意包括野外采样等多个环节,需要结合大量的区域地质资料综合分析,必要时要辅助以其他同位素测年手段进行综合约束,以获得断裂活动的可靠信息.

Based on detailed structural decipher on different kinds of faults in west Shandong and Yi-Shu fault zone, samples contained apatite have been collected continuously in structural belts and un-deformed geologic body near faults. By means of low-temperature testing skill of apatite fission track, combined with analysis of data achieved in laboratory and reverse modeling of apatite fission track, the time limit of deferent faults movement can be efficiently restricted. Many detailed processes, including collection of outcrop samples, should be concerned when this method is applied because of the low temperature sensitivity and restricted range to temperature of apatite fission track. For the sake of obtaining reliable time limit of fault movement, it is necessary to seek regional geologic information for further analysis and other isotope chronology might also be advised to restrict the time limit of fault movement.