【摘要】 本文采用高精度的４０Ａｒ－３９Ａｒ计时技术，系统地测定了滇西泸水钨锡矿床片麻状花岗岩、锡矿石和钨矿石中的白云母和石英等矿物的年龄，结合野外地质情况和岩矿薄片镜下特征，查明该矿为多期成矿：片麻状花岗岩年龄为１６３Ｍａ，锡矿１４５Ｍａ，钨矿有两期，分别为６９Ｍａ和３９Ｍａ。同时研制了金属超高真空碎样提氩装置，并与ＭＭ－１２００质谱计系统连接，测定了钨矿石中石英的流体包裹体的４０Ａｒ－３９Ａｒ年龄，为矿床形成年龄测定开辟了新的实验测试途径。更多还原

【Abstract】 Seven samples from the Lushui granite-associated tin-tungsten deposit were dated using the 40Ar-39Ar steppedly heating technique.In order to investigate the possibility of dating the fluid inclusions hosted in quartz using the 40Ar-39Ar method,one sample of quartz was crushed in vacuum to release the contained gas,and meaningful results were obtained.The resulted data indicate that the deposit was formed through three episodes of mineralization.Three samples of muscovite from the associated granite show similar smoothly rising age spectra with a maximum age of 162.8±0.3 Ma (1SD).The tin mineralization has an age of 145 Ma.There existed two periods of tungsten mineralization,which correspond to 69.2±1.3 Ma and 38.8 ±0.6 Ma in age(plateau ages of muscovite),respectively.The quartz crushed in vacuum shows a smoothly falling age spectrum marked by old age at the low value of 39Ar release,and the minimum age is larger than the real,which implies that excess 40Ar may have been trapped in inclusions during the crystallization of quartz.The isochron age of quartz,38.6±1.9 Ma,agrees with those of the coexisting muscovite obtained through the 40Ar-39Ar steppedly heating technique.更多还原