新疆阿尔泰克朗盆地热液成矿时代的裂变径迹分析

Fission Track Thermochronology Application to Mineralization Ages of Hydrothermal Deposits in Kelang Basin,Northern Xinjiang,China

应用裂变径迹技术研究成矿作用是一种新尝试。新疆克朗盆地各个矿区成矿流体包裹体均一温度变化于105~294℃,与锆石和磷灰石裂变径迹封闭温度基本一致,所以,裂变径迹方法用于可以应用于成矿作用研究。本文获得不同矿区6个锆石和17个磷灰石裂变径迹分析结果,其中锆石年龄为134 Ma^312 Ma,分属312 Ma,247Ma和158~134 Ma三个年龄组,是3个成矿期的体现;磷灰石年龄为30~130 Ma,是区内成矿作用结束后的热事件时代。因此,成矿作用不仅发生于海西期和印支期,而且发生于燕山期甚至喜山期。

It is a new attempt to apply Fission track thermochronology to mineralization field and it is feasible because the homogenization temperature of metallogenic fluid inclusions from different ore deposits in Kelang basin, northern Xinjiang ranges from 105 ℃ to 294 ℃ and accords with the retentions temperature of fission tracks in zircon and apatite on the whole. This study has achieved 6 zircon and 17 apatite fission track analysis results. The zircon fission track ages range from 134 Ma to 312 Ma and are divided into three groups of 312 Ma, 247 Ma and 158 - 134 Ma. We consider that the three age groups reflect three metallogenic epochs. The apatite ages are between 30 Ma and 130 Ma, belong to end of the metallogenic thermal events. Consequently, the mineralization occurred not only in Hereynian and Indosinian epochs, but also in Yanshanian epoch, even in Himalayan epochs.