摘要
小柯勒河铜-钼矿床是近年来大兴安岭成矿带内新发现的大型斑岩型矿床,对其开展蚀变矿物研究,有助于深入揭示我国东北晚中生代斑岩型铜-钼矿床的成矿特征,并建立新的区域找矿勘查标识体系。本研究利用短波红外光谱(SWIR)技术对地表1条勘探线剖面采集的样品进行蚀变填图,并对云母类矿物开展了光谱学特征及主量元素化学成分分析。研究结果表明,小柯勒河矿区地表的蚀变范围直径超过3500 m,钻孔揭露的垂向热液蚀变范围超过1300 m,表明成矿过程中经历了大规模的热液蚀变作用,暗示该矿床具有较大的找矿潜力。此外,矿区钾化蚀变主要发育在深部的花岗闪长斑岩体内,且与铜-钼矿化密切相关,指示钾化蚀变带为矿区重要的找矿标志。SWIR分析结果显示,地表勘探线中云母族矿物的结晶度(IC值)一般>1.5,明显高于深部赋矿钾化带内云母族矿物的IC值(<1.0)。因此,云母族矿物IC值的空间变化可用于指示隐伏矿体的方位。电子探针分析表明,地表成矿岩体内发育的白云母具有较高的MgO(高达3.19%)和较低的FeO(低至0.61%)含量,与周围地层样品中较高的FeO(高达4.44%)和较低的MgO(低至0.35%)含量存在显著差异。而这种差异通常与温度和压力的变化密切相关,因而白云母的短波红外及地球化学特征在辅助识别热液中心方面展现出良好的应用前景。本文认为,蚀变矿物勘查标识可为浅覆盖区斑岩矿床隐伏矿体的定位提供强有力的技术支撑与理论依据。
The recently identified Xiaokelehe porphyry Cu-Mo deposit,a large deposit situated in the northern segment of the Great Xing’an Range,presents valuable opportunities for altered mineral research.Such investigations will deepen our understanding of the metallogenic characteristics and contribute to the identification of exploration indicators for Late Mesozoic porphyry Cu-Mo deposits in Northeast China.This study utilizes Short-Wavelength Infrared(SWIR)spectroscopy to conduct alteration mapping on samples collected from a surface exploration line profile.Additionally,the spectroscopic features and major element compositions of muscovite-group minerals were analyzed.The results indicate that the surface alteration zone of the Xiaokelehe mining area has a diameter of over 3500 meters in,while drill core data reveal that the hydrothermal alteration zone exceeds 1300 meters in vertical extent.These findings suggest extensive hydrothermal alteration during the mineralization period,indicating that the deposit has substantial exploration potential.Furthermore,potassic alteration in the mining area is predominantly concentrated in the deep granodiorite porphyry and is closely associated with Cu-Mo mineralization,highlighting that the potassic alteration zone serves as a key prospecting indicator in this region.SWIR analysis shows that the crystallinity index(IC value)of muscovite-group minerals along the surface exploration line generally exceeds 1.5,which is significantly higher than that of muscovite-group minerals in the deep mineralized potassic alteration zone(<1.0).Consequently,spatial variations in the IC values of muscovite-group minerals can serve as an effective indicator for locating concealed ore bodies.EPMA analysis reveals that muscovite in the surface mineralized rocks exhibits high MgO(up to 3.19%)and low FeO(as low as 0.61%)contents,which contrasts sharply with the high FeO(up to 4.44%)and low MgO(as low as 0.35%)contents observed in the surrounding stratigraphic samples.These distinct geochemical characteristics of muscovite underscore its potential as an indicator for identifying hydrothermal centers.Such variations are typically closely associated with changes in temperature and pressure.Therefore,the short-wave infrared and geochemical characteristics of muscovite show significant potential for aiding in the identification of hydrothermal centers.This study suggests that alteration mineral exploration indicators can provide robust technical support and a solid theoretical basis for locating concealed ore bodies in porphyry deposits in shallow overburden areas.
作者
孟凡波
刘纬鹏
顾鹏
宋莹
冯雨周
陈旭升
孙福鑫
张世涛
肖兵
唐尧
邓昌州
MENG Fanbo;LIU Weipeng;GU Peng;SONG Ying;FENG Yuzhou;CHEN Xusheng;SUN Fuxin;ZHANG Shitao;XIAO Bing;TANG Yao;DENG Changzhou(Qiqihar Institute of Geological Exploration of Heilongjiang Province,Qiqihar 161006,Heilongjiang,China;State Key Laboratory of Critical Mineral Research and Exploration,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,Guizhou,China;State Key Laboratory of Deep Earth Processes and Resources,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,Guangdong,China)
出处
《大地构造与成矿学》
北大核心
2026年第1期30-42,I0007-I0014,共21页
Geotectonica et Metallogenia
基金
黑龙江省自然资源厅国土科研项目(201701)
黑龙江省财政项目(YBZQ-202301)联合资助。
关键词
小柯勒河
斑岩铜-钼矿床
蚀变矿物
勘查标识
大兴安岭成矿带
Xiaokelehe
porphyry Cu-Mo deposit
altered minerals
exploration indicator
Great Xing’an Range Metallogenic Belt
