湖南千里山复式花岗岩体的地球化学特征和物质来源

Geochemical Characteristics and Material Sources of the Qianlishan Composite Granite Body, Hunan province

千里山复式花岗岩体是柿竹园大型稀有－有色金属矿床的成矿母岩。它具有高硅、过铝质、富不相容元素、强铕负异常、低ε＿（Ｎｄ）、较高的（￣（８７）Ｓｒ／＿（８６）Ｓｒ）＿ｉ、￣（２０７）Ｐｂ／＿（２０４）ｐｂ和δ￣（１８）Ｏ值等特征，表明该岩体来源于地壳物质，属陆壳改造型花岗岩。弱的铈负异常以及较古老的Ｎｄ模式年龄进一步证实，原始岩浆主要由区内未出露的中元古宙变质沉积岩部分熔融形成。

As the metallogenic parent rocks of the Shizhuyuan large-sized rare element-nonfer-rous metallic deposit,the Qianlishan complex granite body is characterized by highsilica,peraluminous rocks,rich incompatible elements, strong negative Eu anomalies,lowε_(Nd),and relative high(￣(87)Sr/￣(86)Sr)_i,￣(207)pb/_(204)pb and δ￣(18)O values.These features suggest thatthe Qianlishan rock body was derived from the crustal material,thus belonging to con-tinental crust transformation type. Furthermore,weak negative Ce anomalies and compa-ratively old model ages imply that the original magma was formed mainly by partialmelting of the unexposed middle Proterozoic metasedimentary rocks in the study area.