滇西南澜沧江带红豆山铜矿花岗斑岩地质地球化学特征及成岩时代

发布时间：2018-06-29 22:28

本文选题：南澜沧江带 + 花岗斑岩　；参考：《地质通报》2017年07期

【摘要】：南澜沧江火山弧带红豆山花岗斑岩属于过铝质钾玄岩性S型花岗岩,SiO_2含量为71.1%~74.4%,全碱含量高(K_2O+Na_2O=8.4%~9.4%),富钾(K_2O/Na_2O=3.9~5.0),铝饱和指数(A/CNK)为1.06~1.21;具轻稀土元素富集特征,负Eu异常(δ Eu=0.53~0.74);相对富集大离子亲石元素(LILE,如Rb、Ba、Th、U等),但亏损Sr、P、Ti等元素。地球化学特征表明,红豆山花岗斑岩具火山弧花岗岩与同碰撞花岗岩的特征,为活动大陆边缘弧的产物。红豆山花岗斑岩的LA-ICP-MS锆石U-Pb年龄为220.3±3.6Ma,形成于晚三叠世。红豆山花岗斑岩的地球化学特征和形成时代与小定西组基性火山岩非常相似,两者是同一期岩浆活动不同阶段的产物。
[Abstract]:The Hongdoushan granitic porphyry in the southern Lancangjiang volcanic arc zone belongs to the peraluminous kalitic S-type granite with a content of 71.1% and 74.4%, a high total alkali content (K _ 2O / Na2O-O _ 2O = 8.4%), a K _ 2O / Na _ 2O _ 2O _ (3.95.0), a K _ 2O / Na _ 2O _ 2O _ (3.95.0) and an aluminum saturation index (A / R _ (CNK) of 1.06 ~ 1.21), which are characterized by the enrichment of light rare earth elements (LREE). Negative EU anomalies (未 EU ~ (0.53) ~ (0.74) and relative enrichment of large ion lithophile elements (LILE, such as RbPU), but depletion of elements such as Sr-Pu (Ti). The geochemical characteristics indicate that the Hongdoushan granitic porphyry is the product of active continental margin arc, which is characterized by volcanic arc granite and syncollision granite. The LA-ICP-MS zircon U-Pb age of the Hongdoushan granitic porphyry is 220.3 卤3.6 Ma.It was formed in the late Triassic. The geochemical characteristics and formation age of Hongdoushan granitic porphyry are very similar to the basic volcanic rocks of Xiaodingxi formation, and they are the products of different stages of magmatic activity in the same period.
【作者单位】：昆明理工大学国土资源工程学院;有色地质调查中心西南地质调查所;
【基金】：云南省应用基础研究计划项目《滇西云县红豆山铜矿床流体地球化学和成矿年代学研究》(编号:201401CD00230) 云南省矿产资源预测评价工程实验室及省、校创新团队项目
【分类号】：P618.41

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