投稿时间：2011-08-31
修订日期：2012-03-25
中文摘要:山西堡子湾金矿为一隐爆角砾岩型金矿,新近在其南西9 km处的九对沟地区又发现了隐爆角砾岩型钼矿。堡子湾金矿与二长花岗(斑)岩成矿关系密切,矿区二长花岗(斑)岩为过铝质钙碱性岩石,w(SiO2)为74.22%,K2O/Na2O比值为0.88,w(K2O+Na2O)为3.32%,铝饱和指数A/CNK为1.97,σ为0.35;ΣREE为66.4×10-6,无明显Eu异常(δEu=0.93)。九对沟钼矿则与流纹斑岩具成因联系,该流纹斑岩为过铝质高钾钙性岩石,w(SiO2)为75.92%~77.0%,K2O/Na2O比值为1.94~44.67,w((K2O+Na2O)为5.48%~7.4%,铝饱和指数A/CNK为1.35~1.65,σ为0.91~1.61;ΣREE为80.6×10-6~100.2×10-6,具弱负Eu异常(δEu=0.49~0.74)。与成矿密切相关的两类岩石同位素地球化学特征〔(87Sr/86Sr)初始比值为0.703301~0.706664,εNd(t)为-9.42~-19.39〕显示:它们可能来自Ⅰ型富集地幔,为同一源区岩浆演化而来的不同产物。氧化程度高、分异演化程度低的二长花岗质岩浆是形成堡子湾金矿床的重要控制因素,而相对氧化程度低、分异演化程度高的流纹质岩浆与九对沟钼矿化密切相关。
Abstract:The Puziwan gold deposit in Shanxi Province is a cryptoexplosive breccia type deposit. Recently, a cryptoexplosive breccia type Mo deposit was found in Jiuduigou district 9 km southwest of the Puziwan Au ore district. The Puziwan Au deposit is closely related to the monzonitic granite porphyry, which is peraluminous and shows a calc-alkaline trend with SiO2 content of 74.22%, K2O/Na2O value of 0.88, K2O+Na2O content of 3.32%, A/CNK value of 1.97, σ value of 0.35, and REE content of 66.4×10-6, having no obvious Eu anomaly(δEu=0.93). The Jiuduigou Mo deposit has a genetic connection with the rhyolite porhpyry, which is peraluminous and shows a high-K calc-alkaline trend with SiO2 content ranging from 75.92% to 77.0%, K2O/Na2O values from 1.94 to 44.67, K2O+Na2O content from 5.48% to 7.4%, A/CNK values from 1.34 to 1.65, σ values from 0.91 to 1.61, and REE content ranging from 80.6×10-6 to 100.2×10-6, characterized by weak negative Eu anomaly (δEu=0.49~0.74). The characteristics of isotopic geochemistry 〔(87Sr/86Sr)<em>i=0.703301~0.706664,εNd(t)=-9.42~-19.39〕 show that they came from the source region of EMⅠ and seemed to be different products of the same magmatic source. The monzonitic granitic magma with high oxidation degree and low differentiation index might have played an important controlling role in the formation of the Puziwan Au deposit. And the Jiuduigou Mo deposit has a close connection with the rhyolite magma characterized by low oxidation degree and high differentiation index.
文章编号：
中图分类号：P618.51; P618.65
文献标志码：
基金项目:本文得到全国危机矿山接替资源找矿项目(200699105)的资助
引用文本：
龙灵利,王玉往,王京彬,廖震,张会琼,唐萍芝.2012.山西堡子湾-九对沟金(钼)矿区岩石地球化学特征及其意义[J].矿床地质,31(3):493~505LONG LingLi,WANG YuWang,WANG JingBin,LIAO Zhen,ZHANG HuiQiong,TANG PingZhi.2012.Petro-geochemistry of Puziwan-Jiuduigou Au (Mo) ore district in Shanxi and its significance[J].Mineral Deposits31(3):493~505
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