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赣南漂塘钨矿共生白云母和锡石40Ar/39Ar定年对比研究,前者采用激光阶段加热分析,后者采用真空击碎法提取流体包裹体.白云母形成平坦的年龄谱,坪年龄为159.3±1.5Ma(2σ).锡石形成下降型年龄谱,最初6个阶段表观年龄明显偏老且迅速下降,从3954Ma降至196Ma,表明锡石中次生包裹体含有过剩氩;第7～18阶段形成了年龄坪,坪年龄为159.1±1.8Ma,对应的数据点构成高度线性相关的等时线,等时年龄为158.6±2.9Ma,代表了原生包裹体的年龄.锡石原生包裹体年龄与白云母年龄一致,代表了漂塘钨矿的形成年龄.研究结果表明锡石是40Ar/39Ar真空击碎分析理想的定年对象,其原生包裹体年龄代表了成矿年龄.继闪锌矿之后,再次拓展了流体包裹体40Ar/39Ar法应用于矿石矿物直接定年测试对象.
The 40Ar / 39Ar dating of symbiotic muscovite and cassiterite from the Tongtuang tungsten deposit in Gannan was studied by laser heating in the first stage and fluid inclusions in the latter by vacuum crushing.The muscovite was formed with a flat age spectrum of 159.3 ± 1.5Ma (2σ). The descending age spectrum of cassiterite was formed. The apparent ages of the first six stages were obviously older and decreased rapidly from 3954Ma to 196Ma, indicating that the secondary inclusions in cassiterite contained excess argon. The age of Ping Formation was 159.1 ± 1.8Ma at 18th stage, and the corresponding data points formed a highly linear isochronous line with an isochron age of 158.6 ± 2.9Ma, representing the age of the primary inclusions. The age is consistent with the age of muscovite, representing the formation age of Tongtu tungsten ore.The results show that the cassiterite is the ideal 40Ar / 39Ar vacuum crush analysis of the age of the object, the age of primary inclusions represents the metallogenic age.After the sphalerite Later, the 40Ar / 39Ar method of fluid inclusions was expanded once again to be applied to the direct determination of ores and minerals.