摘要
金川铜镍硫化物矿床是中国最大、世界第三大的岩浆熔离型铜镍硫化物矿床。前人对金川矿床成因及找矿勘查的研究多关注于岩浆来源和演化过程,对于构造控矿作用的定量化分析相对较少。本文综合地质图件资料和勘探工程数据,构建了金川矿床地质体的三维几何模型和包含Cu、Ni矿化分布信息的三维属性模型。随后运用空间距离分析、形态分析等方法定量提取了岩浆通道中轴线距离指标、断层空间距离指标、岩体顶底板距离比值指标、岩体底板起伏指标等构造控矿信息,并分析其矿化定位规律。结果表明:东、西岩体Ni、Cu品位等矿化指标与岩浆通道中轴线距离指标和断层距离指标具有明显的负相关关系。另外,西岩体矿化富集与岩体顶底板距离比值指标具有正相关关系,西岩体底板起伏指标取值为0 m或小于0 m时矿化富集更明显,而在东岩体这些趋势相对不明显。综上可知:F_(16-1)断层可能为早期的控矿断层,该断层以及其次级断裂可能为运移通道;金属硫化物倾向于在岩体底板的平缓处或较凹陷处富集成矿,尤以西岩体更为明显;推测西岩体原始产状较平缓,东岩体原始产状较陡峭。
The Jinchuan Ni-Cu-(PGE)deposit is one of the largest magmatic sulfide deposits in the world.A large number of previous studies on the genesis and mineral prospectivity of the Jinchuan deposit have focused on the source and evolution of magma,whereas relatively few attention to quantitative analysis of structural orecontrolling mechanism.Based on geological maps and exploration databases,a 3D geometric model of the geological objects of deposit and a 3D attribute model containing Cu and Ni grades are generated in this paper.Subsequently,the feature extraction methods such as the spatial distance analysis and morphology analysis are used to extract the structural ore-controlling information including the distance to central axis of the magma conduit,the distance to faults,relative position between the intrusion roof and floor,and the intrusion floor shape.Furthermore,we analyzed ore-controlling laws of above features,and the results show that the mineralization enrichment of Ni and Cu in western and eastern intrusions are both negatively correlated with the distance to central axis of the magma conduit and the distance to faults.In addition,the mineralization in western intrusion is positively correlated with relative position between the intrusion roof and floor,and the mineralization enrichment is relatively obvious when the degree of the intrusion floor shape<=0,while these trends are relatively inconspicuous in the eastern intrusion.Therefore,fault F_(16-1) may be an early ore-controlling fault,and this fault as well as its secondary faults may play a role in magma transport.In addition,the sulfides tend to be mineralized at the flat areas or the depressed area of the intrusion floor,especially in the western intrusion.It is speculated that the original occurrence of the western intrusion is gentle,while the eastern intrusion is steeper.
作者
苏哲
毛先成
黎隆交
刘欣雨
SU Zhe;MAO Xiancheng;LI Longjiao;LIU Xinyu(Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring(Ministry of Education),School of Geosciences and Info-Physics,Central South University,Changsha 410083,Hunan China;Hunan Key Laboratory of Nonferrous Resources and geological Hazard Detection,Changsha 410083,Hunan China)
出处
《矿产勘查》
2023年第5期679-690,共12页
Mineral Exploration
基金
国家自然科学基金重点项目“矿床时空结构定量表征与智能理解”(42030809)
湖南省科技创新计划项目(2021RC4055)联合资助。
关键词
构造控矿规律
控矿信息提取
铜镍硫化物矿床
金川矿床
structural ore-controlling laws
geological feature extraction
Ni-Cu-(PGE)deposits
Jinchuan deposit
