中文摘要：

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（ecr）．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．

英文摘要：

The aim of this study is to investigate the possibility of dating fluid inclusions in cassiterite using the ^40Ar/^39Ar technique by crushing in vacuo. Paragenous muscovite and cassiterite in a piece of tungsten ore from the Piaotang tungsten deposit in southern Jiangxi Province were selected. Laser stepwise heating of the muscovite yields a flat age spectrum with a plateau age of 159.3±1.5 Ma. The ^40Ar/^39Ar dating result of cassitefite by crushing forms a declining age spectrum marked by the highest apparent age of 3954 Ma at the 1st stage, then shows an apparent decline step-by-step, and finally a plateau appears with a plateau age of 159.1±1.8 Ma in the last 12 stages （from 7 to 18, or about 83% of the total 39At）. The data points of cassiterite clearly distribute into two groups corresponding to secondary and primary fluid inclusions, and their mixtures. The secondary ones contain excess 40At and their data points scatter on the inverse isochron diagram of ^40Ar/^39Ar vs. ^40Ar/^39Ar, while the primary ones do not contain excess 40At and their data points yield an excellent isochron line corresponding to an age of 158.6±2.9 Ma. The ^40Ar/^39Ar isochron age of the cassiterite by crushing is well concordant with the age of the paragenous muscovite by ^40Ar/^39Ar stepwise heating, indicating that mineralization occurred at 159 Ma. This study reveals that cassiterite is a suitable dating target for ^40Ar/^39Ar stepwise crushing. Moreover, the isochron age of the primary inclusions represent the mineralization age of the Piaotang tungsten deposit.