小秦岭303号石英脉流体包裹体Rb-Sr、^(40)Ar-^(39)Ar成矿年龄测定

Rb Sr and ^(40)Ar^(39)Ar dating of fluid inclusion of the No-303 quartz vein in Xiaoqinling region

用石英流体包裹体ＲｂＳｒ、４０ Ａｒ３９ Ａｒ 法测定了小秦岭３０３ 号石英脉的形成时代为古元古代。其流体包裹体属Ｈ２ Ｏ＋ ＣＯ２ ＋ ＮａＣｌ 型，盐度（ ｗＮａＣｌ） 为６－５％ ～１２－９８％ ，ＣＯ２ 含量高，Ｎａ ＋ Ｋ＋ 。３０３ 号石英脉ＲｂＳｒ 等时线年龄为（２ ３８２±３３６） Ｍａ ～（２ ２３４ ±４７） Ｍａ ，（８７Ｓｒ／８６Ｓｒ）ｉ 为（０－７３５ １±０－００１ ９） ～（０－７４１ ６±０－０００ ４） ，４０ Ａｒ３９ Ａｒ 坪年龄为（２ ０４６－７４ ±４０－９３）Ｍａ ，等时线年龄为（２ ００５－８８±４０－１２）Ｍａ，（４０ Ａｒ／３６ Ａｒ）。为３０５－３２８ ３。小秦岭金矿自元古宙以来伴随着构造岩浆活动或变质作用，可能经历了多期成矿作用，包括中岳期、晋宁期、印支期和燕山期。

The forming age of the No 303 quartz vein of Xiaoqinling region has been determined as Zhongyue Period (Palaeoproterozoic) by Rb Sr and 40Ar 39Ar isotope dating of fluid inclusion in quartz The fluid inclusions in the quartz belong to H2O+CO2+NaCl type, in which the content of CO2 is high, the salinity (wNaCl) is 6 5%～12 98%, and Na+K+ Rb Sr isochron age of the No 303 quartz vein is (2 382±336)～(2 234±47) Ma, (87Sr/86Sr)i value is (0 735 1±0 001 9)～(0 741 6±0 000 4), 40Ar 39Ar plateau age is (2 046 74±40 93) Ma, 40Ar 39Ar isochron age is (2 005 88±40 12) Ma, and (40Ar/39Ar)0 value is 305 328 3 Accompanying tectonomagmatic action or metamorphism, Xiaoqinling gold deposits had been experienced multi stage mineralizations since Palaeoproterozoic, including Zhongyue epoch, Jinning epoch, Indo Chinese and Yanshan epoch