贵州织金新华含稀土磷矿床稀土元素地球化学及生物成矿基本特征

REE GEOCHEMISTRY OF THE ORE-BEARING REE IN XINHUA PHOSPHORITE,ZHIJIN,GUIZHOU

对贵州织金新华含稀土磷矿床进行的稀土元素及微量元素分析结果表明 ,磷块岩中普遍富集稀土元素 ,稀土总量Σ REE较高 ,并富集 Y元素及 L a,Nd等轻稀土元素。L REE/ HREE比值较高。含稀土磷块岩普遍具 Ce负异常 ,显示其对源区的继承性 ,指示成磷环境处于氧化程度相对较高状态。稀土元素球粒陨石标准化模式曲线、北美页岩标准化模式曲线、Ce元素异常、L REE/ HREE比值、微量元素特征及岩石矿物特征表明 ,织金新华含稀土磷矿床具以正常海相生物 -化学沉积等为主伴有海相热水沉积混合成因的特征。在磷矿成矿过程中沉积物沉积时 ,活体生物及死亡残骸不同程度地摄取和富集了 L a,Nd,Ce等稀土元素、Y元素及其他微量元素 ,沉积在含磷层位 ,构成大量的含稀土、含生物碎屑白云质磷块岩。

The REE and compsition of trace element analysis show that phosphorite-ores are rich in REE in Xinhua.The phosphorite has abundant Y,La,Nd-elements and the LREE/HREE ratio is higher in ore-depsit and lower on top of roof rock.The Ce anomaly indicate a high oxidation environment and inheritance of orginal region.REE patterns of chondrite-normailzed and NASC-normalized Ce anomaly,LREE/HREE ritio,characteristic trace elements and mineral rock showed that the deposit is characterized by biochemical sediments and mixture of hot seawater sedimentation. This paper discussed the character and regularity of migration and concentration in the oxidizedorebody of the phosphorite in Xinhua.