Rare-Earth Elements Geochemistry of Nage Cu Polymetallic Deposit,Congjiang County,Southeast Guizhou Province,China

Nage Cu polymetallic deposit,a typical deposit in Congjiang County,southeast Guizhou province,China,is located in the southwest Jiannan Block.The ore deposit are hosted in Neoproterozoic strata and structurally controlled by EW-trending fault.The ore body is coexisting with diabase dyke in space.REE of ores,host rocks,granite and granite porphyry bulk-rocks were analyzed by ICP-MS.Results show that the ∑REE of ores bulk-rocks range from 6.61×10-6 to 235×10-6,with LREE-enriched and negative Eu anomaly(0.59-0.88);∑REE of host bulk-rocks range from 74.2×10-6 to 286×10-6,characterized by LREE-enriched and negative Eu anomaly(0.79-0.88);Diabase samples have ∑REE ranging from 78.1×10-6 to 90.9×10-6,with slightly LREE-enriched and unconspicuous Eu anomaly(0.98-1.01);Granite samples have stable ∑REE contents,ranging from 132×10-6 to 193×10-6,enrich in LREE with Eu-depleted(0.55-0.79);Granite porphyry bulk-rocks samples have relatively lower ∑REE contents(74.9×10-6-120×10-6) than granite,characterized by obviously LREE-enriched and prominent negative Eu anomaly(0.44-0.56).Based on comparative study on contents,parameters and patterns of REE for whole rock of ores,host rocks and igneous rocks,we consider that the REE in the ore-forming fluids were originated from host rocks.