CAJ | 학술논문

河南周庵超基性岩体蕴含大型Ni-Cu-(PGE)硫化物矿床,矿化带位于超基性岩体边缘与围岩的接触带.周庵超基性岩体轻稀土富集,其La/Sm_N比值为1.3～4.7,Sm/Yb_N比值为1.9～4.4,显示一定程度的LREE/HREE分异.原始地幔标准化的微量元素配分型显示弱的负Nb异常.岩体的M含量为70×10~(-60～2120×10~(-6),Cu含量为15×10~(-6)～1056×10~(-6);矿石的Ni含量为2592×10~(-6)～6549×10~(-6),Cu含量为1147×10~(-6)～3239×10`(-6).矿石的Ni/Cu比值(2.0～2.3)低于岩石样品(5-83).强蚀变矿化样品的PGE元素含量高于弱蚀变样品约一个数量级,所有样品的Pd/Ir和Pt/Ir比值高,Pd/Ir=1.4～21,Pt/Ir=2.4～22,表明PPGE相对IPGE富集.上述特征显示周庵岩体是构造侵位的地幔岩,岩体与围岩发生了较强烈的物质交换,含水流体交代作用导致了岩体-围岩物质交换和岩体边缘矿化.
하남주암초기성암체온함대형Ni-Cu-(PGE)류화물광상,광화대위우초기성암체변연여위암적접촉대.주암초기성암체경희토부집,기La/Sm_N비치위1.3～4.7,Sm/Yb_N비치위1.9～4.4,현시일정정도적LREE/HREE분이.원시지만표준화적미량원소배분형현시약적부Nb이상.암체적M함량위70×10~(-60～2120×10~(-6),Cu함량위15×10~(-6)～1056×10~(-6);광석적Ni함량위2592×10~(-6)～6549×10~(-6),Cu함량위1147×10~(-6)～3239×10`(-6).광석적Ni/Cu비치(2.0～2.3)저우암석양품(5-83).강식변광화양품적PGE원소함량고우약식변양품약일개수량급,소유양품적Pd/Ir화Pt/Ir비치고,Pd/Ir=1.4～21,Pt/Ir=2.4～22,표명PPGE상대IPGE부집.상술특정현시주암암체시구조침위적지만암,암체여위암발생료교강렬적물질교환,함수류체교대작용도치료암체-위암물질교환화암체변연광화.
The Zhou'an ultramafie intrusion in Henan Province is mainly composed of peridotite and hosts a large Ni-Cu-PGE deposit.The mineralization occurs in the rim of the lense-like intrusive body.Rare earth elements of the ultramafie rocks are characterized by enriched LREE with La/Sm_N = 1.3～4.7 and fractionated LREE and HREE with Sm/Yb_N = 1.9～4.4.Primitive mantle-normalized trace element patterns decline to right,with weakly negative Nb-anomaly.Ni and Cu contents of the host peridotites range from 70 to 2120×10~(-6) and from 15 to 1056×0~(-6),respeetivly,whereas Ni and Cu contents of ores range from 2592 to 6549×10~(-6) and from 1147 to 3239×10~(-6),respectively.The Ni/Cu ratios of ores are between 2.0 and 2.3,which are lower than those in sulfide-barren rocks(5 to 83).The concentrations of PGEs are highly variable in the ores with Pd/Ir ratios ranging from 1.4 to 21 and Pt/Ir ratios from 2.4 to 22.We propose that the Zhou'an uhramafic intrusion is a structurally emplaced segment of lithospheric mantle,and mineralization around the rim of the intrusion can be attributed to hydrothermal alteration.