The fission track analyses show that these samples are under the exhumed partial annealing zone and the apparent ages obtained are cooling ages with part mixed ages.

裂变径迹分析显示样品应处于剥露的部分退火带，其表观年龄主体表现为冷却年龄，部分具混合年龄特征。

youdao

With increasing down-hole temperature, average track lengths also decrease, however, annealing anisotropy of fission tracks in apatite increases.

磷灰石中古裂变径迹的长度也随井温升高而减小，而磷灰石古径迹退火的各向异性却随井温升高而增大。

youdao