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用裂变径迹法测试了甲马矿区矽卡岩矿石和外围砂岩总计5个磷灰石和锆石样品,其中磷灰石裂变径迹年龄为(16.1±0.9)和(18.8±1.1)Ma,代表成矿热液后期活动的时代;砂岩磷灰石裂变径迹年龄为(22.0±4.3)Ma,锆石裂变径迹年龄为(20.9±2.0)Ma,代表早期成矿时代;另一个砂岩锆石年龄为(341.6±79.1)Ma,与成矿作用关系不大,是矿物源区特征的反映.热历史分析表明,成矿作用开始时间应早于25～22 Ma.矿区平均冷却速率为5～6℃/Ma,其中在90～80℃期间降温缓慢;矿区剥蚀程度约为2.7 km,剥蚀速率大于抬升速率.
A total of 5 apatite and zircon samples from skarn ore and peripheral sandstone in Jiama mining area were tested by fission track method. The fission track ages of apatite were (16.1 ± 0.9) and (18.8 ± 1.1) Ma, (22.0 ± 4.3) Ma, and the zircon fission track age is (20.9 ± 2.0) Ma, which represents the early mineralization age. The other zircon sandstone The stone age is (341.6 ± 79.1) Ma, which is not related to the mineralization and is a reflection of the characteristics of mineral source.The thermal history analysis shows that the mineralization start time should be earlier than 25 ~ 22 Ma and the average cooling rate of the ore area is 5 ~ 6 ℃ / Ma, of which slow cooling occurred at 90 ~ 80 ℃. The degree of denudation in the mining area was about 2.7 km, and the denudation rate was higher than the lifting rate.