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在综合对比已有Hf同位素分析方法的基础上,我们选用Ln-Spec(100-150目,H+)特效树脂和多接收器电感耦合等离子体质谱(MC-ICPMS)对4件标准物质和19件岩石样品(新疆东准噶尔的花岗岩及其包体18件、玄武岩1件)进行了全岩Hf同位素研究。所获得的国际标准物质BCR-1、BHVO-2、W-2的176Hf/177Hf比值与文献报道的结果在误差范围内一致,表明所采用的全岩Hf的化学分离和溶液的Hf同位素质谱测定方法是可靠的。本文首次报道了中国花岗岩标样GRS-1的176Hf/177Hf比值,结果为0.282547?07(2?)。依据新疆东准噶尔花岗岩及其包体样品的全岩176Hf/177Hf比值、全岩样品在等离子体质谱(ICP-MS)上测定的Lu、Hf含量和岩石的形成年龄(300 Ma),得到这些样品的全岩εHf(t)。它们与对应样品的锆石εHf(t)在误差范围内总体上的一致性表明,ICP-MS测定的Lu、Hf含量可以用来计算年龄值约300 Ma的全岩初始Hf同位素组成。玄武岩样品QS08-1的全岩εHf(t)与该蛇绿岩套斜长花岗岩的锆石εHf(t)的高度吻合,为利用全岩176Hf/177Hf比值和ICP-MS测定的全岩Lu、Hf含量,研究没有或难以选出锆石的较年轻岩石的Hf同位素组成提供了很好的实例。
Based on a comprehensive comparison of Hf isotope analysis methods, Ln-Spec (100-150 mesh, H +) special effects resin and multi-receiver inductively coupled plasma mass spectrometry (MC-ICPMS) Rock samples (18 in East Junggar granitic and its inclusions, 1 basaltic) were studied for Hf isotopic studies of whole rocks. The 176Hf / 177Hf ratios of the obtained international reference materials BCR-1, BHVO-2 and W-2 are consistent with the reported results in the error range, indicating that the chemical separation of the whole rock Hf and the Hf isotope mass spectrometry of the solution The method is reliable. This paper reports for the first time the 176Hf / 177Hf ratio of GRS-1 from Chinese granite standard, which is 0.282547 07 07 (2)). Based on the ratio of 176Hf / 177Hf to the total rock mass of the eastern Junggar granite and its inclusions, the Lu, Hf contents and the age of rock formation (300 Ma) of the whole rock samples were determined by ICP-MS, and these samples were obtained Of the whole rock εHf (t). The overall agreement of error εHf (t) with their corresponding samples indicates that the Lu and Hf contents measured by ICP-MS can be used to calculate the initial Hf isotopic composition of the whole rock with an age of about 300 Ma. The complete rock εHf (t) of the basalt sample QS08-1 is in good agreement with the zircon εHf (t) of the ophiolite mafic granite. It is the total rock Lu determined by the ratio of 176Hf / 177Hf and ICP-MS, Hf content, a good example is to study the Hf isotopic composition of younger rocks that have no or difficult zircons to be selected.