【摘要】 测定了黄陵背斜核部被称作“孔兹岩系”的 5个全岩样品Ce、Nd同位素组成 ,5个样品分别代表该岩系不同层位与岩性。其中两个含有石墨的黑云斜长片麻岩和一个含榴黑云石英片岩样品的εCe(t)都是负值 (分别为 - 2 5、- 2 1和 - 1 7) ,εNd(t)值相对高 (分别为 - 0 5、- 1 3和- 1 6) ,揭示了岩石中含有较多幔源组分 ,原岩沉积环境不稳定 ;一个石榴石矽线石石英片岩的εCe(t)值为 +1 6,εNd(t)值是 - 2 4 ,指示原岩的沉积环境符合形成孔兹岩的地质条件 ;黑云变粒岩的所有特征与基底片麻岩相似 ,εCe(t)和εNd(t)值分别为 +2 2和 - 7 7,Nd模式年龄为 (3169± 19)Ma ,表明它可能不属于古元古代。总之 ,黄陵地区古元古代的沉积构造环境并不全是稳定的 ,在岩系沉积开始阶段和中间某个时期有明显的海底幔源组分活动 ,因此 ,符合孔兹岩形成条件的沉积 -构造环境只在其中一段时间里存在 ,另外有一些地层可能属于太古宙。更多还原

【Abstract】 The Ce and Nd isotopic components of five whole rock samples of khongalite from the Huangling area of western Hubei province are reported. Two samples of graphite bearing biotite plagioclase gneiss and one sample of garnet bearing biotite quartz schist have negative ε ce ( t ) values ( -2.5 , -2.1, -1.7) and low negative ε Nd ( t ) values (-0.5, -1.3, -1.6), showing much mantle derive components included in these rocks; A sample of garnet sillimanite quartz schist has a positive ε ce ( t ) value (+1.6) and higher negative ε Nd ( t ) value(-2.4), suggesting a relative stable sedimentary setting of its primary rocks; A sample of biotite granulite has similar Ce and Nd isotopic components to those of the basement gneiss in this area with ε ce ( t )=+2.2, ε Nd ( t )=-7.7 and Nd model age of (3169±19) Ma. So, the so called "khongalite" in this area might include proto proterozoic Al rich metasedimentary rocks and Archean basement gneiss.更多还原