豫西陆院沟金矿床正长斑岩脉蚀变围岩的元素迁移规律  

Migration Regularities of Elements in Altered Wallrocks around the Syenite Porphyry Dyke in the Luyuangou Gold Deposit,Western Henan

作　　者：刘亚剑 雷万杉[2] 张海东[2] 夏明哲[2] 张磊[2] 

机构地区：[1]紫金矿业洛宁华泰矿业开发有限公司,河南洛阳471700 [2]长安大学地球科学与资源学院,西安710054

出　　处：《矿物岩石地球化学通报》2015年第6期1247-1253,共7页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：中央高校基本科研经费项目(2014G1271067)

摘　　要：为探讨陆院沟矿区斑岩在成矿中的作用,依据质量平衡方程和等比线法,对斑岩株蚀变围岩的元素迁移规律进行定量分析。结果表明,紧邻侵入体的强蚀变围岩中主量元素相对迁移率为-168.2%~71.9%,矿化元素相对迁移率为23.9%~611.7%,远离侵入体的弱蚀变围岩中主量元素相对迁移率为-53.1%~42.5%,矿化元素相对迁移率为-52.5%~43.9%。Si O2迁出率随蚀变增强而升高;K2O质量分数随蚀变增强先降后升,Mg O和Ca O亦如此;Na2O随蚀变增强先升高后期迁出殆尽,Ti O2、Fe O、Fe2O3、Mn O和P2O5等与之规律相似。正长斑岩侵位早期蚀变流体以富气、少水、高能为特征,蚀变范围广,强度低,以绿泥石化为主;侵位中后期形成富水、赋矿的流体,蚀变范围小、强度大,以钾化、绿泥石化和矿化为主。陆院沟矿区内斑岩株是花山岩基的延伸,是深部能量、流体和矿质释放的通道。In order to discuss the role of syenite porphyry dyke on the gold mineralization in the Luyuangou gold deposit,migration regularities of elements in altered wallrocks around the syenite porphyry dyke have been quantitatively probed by using mass-balance equation and isocon graphic methods proposed by Grant. Results show that relative migration rates of major elements in altered wallrocks near the syenite porphyry dyke vary from-168. 2% to 71. 9%,whereas those of oreforming elements in those altered wallrocks vary from 23. 9% to 611. 7%. However,migration rates of major elements in altered wallrocks far away from the syenite porphyry dyke range from-53. 1% to 42. 5%,while those of ore-forming elements range from-52. 5% to 43. 9%. Si O2 is gradually migrated into the altered wallrocks with the enhancement of alteration. The mass portions of K2 O,Mg O and Ca O of altered wallrocks are decreased firstly and then increased secondly with the increase of alteration intensity. However,the mass portions of N2 O,Ti O2,Fe O,Fe2O3,Mn O,and P2O5 of altered wallrocks are increased firstly and then increased secondly with the increase of alteration intnesity. In early stage of syenite porphyry dyke intrusion,the alteration fluid,which is characteried with rich gas,poor water and high energy,caused a broader zone of weak chloritization. In late stage of syenite porphyry dyke intrusion,the alteration fluid,which is enriched in water and ore-forming material,caused a narrow zone of strong chlorite and potassic alteration and mineralization. It is believed that the syenite porphyry dyke in the Luyuangou gold deposit could be a branch of the Huashan granite batholith,and could provide a channel way for releasing energy,fluid and ore-forming materials. The correlation between alteration and mineralization associated with the syenite porphyry dyke in the Luyuangou gold deposit provides a new thinking way for the mineral prospecting in the region.

关 键 词：元素迁移规律 质量平衡计算 正长斑岩株 陆院沟金矿 

分 类 号：P618.51[天文地球—矿床学]