辽东白云金矿床成因研究

发布时间：2018-01-04 09:34

本文关键词：辽东白云金矿床成因研究　出处：《昆明理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：白云金矿位于辽宁省凤城市青城子镇白云山村,是辽东青城子矿集区北部的超大型金矿床。白云金矿矿体主要产于辽河群盖县组片岩地层中,矿化类型主要有硅钾蚀变岩型和含金石英脉型,受层位控制明显。本文在综合整理前人资料基础上,重点开展了矿床地质特征、矿区及外围岩浆岩的同位素年代学和岩石地球化学、钾长石和黄铁矿的矿物成分等研究,对矿床成因和成矿物理化学条件进行了分析和总结,构建了矿床的岩浆热液成矿模式。白云金矿矿体呈似层状和脉状产于盖县组矽线石云母片岩地层中或矽线石云母片岩与大理岩的岩性界面上,直接或间接的受韧性剪切带和破碎带的控制,矿体与石英斑岩、花岗斑岩岩脉空间关系密切。石英脉型矿体与硅钾蚀变岩型矿体处于同一构造-岩浆热液系统,断裂带为压性环境时,含矿流体渗滤交代围岩形成硅钾蚀变岩型矿体,而当断裂产状较陡或张性环境时,含矿流体则沿裂隙贯入形成含金石英脉型矿体。矿区岩浆岩主要发育脉岩,岩性有辉长岩、煌斑岩、闪长玢岩、花岗斑岩、石英斑岩和二长斑岩等,宏观地质特征显示其侵位顺序为辉长岩→花岗斑岩→石英斑岩→闪长玢岩→煌斑岩→二长斑岩。锆石U-Pb同位素定年表明,矿区脉岩主要形成于元古代、印支期和燕山期三期,其中辉长岩1252.7±8.8Ma,花岗斑岩 218.6±0.4Ma,石英斑岩 218.5±2.9Ma,闪长玢岩 229.0±1.0Ma,二长斑岩164.4±0.4Ma。另外,矿区南部新岭地区煌斑岩年龄为220±2.0Ma,双顶沟岩体中心相粗粒花岗岩年龄为218.5±0.9Ma。双顶沟岩体从中心向外大致可分为中心相(粗粒黑云母花岗岩)、主体相(斑状黑云母二长石花岗岩)和边缘相(细粒花岗岩),发育岩浆混合作用,岩体成岩过程中有幔源物质的参与。矿区脉岩的地球化学特征显示具有岩浆混合的成分变化特征。矿区花岗斑岩脉与双顶沟岩体主体相斑状黑云母二长花岗岩主、微量元素特征相似;而石英斑岩则与双顶沟岩体中心相粗粒黑云母花岗岩相似。综合分析表明,矿区的花岗斑岩和石英斑岩与双顶沟岩体可能为同一岩浆系统,并与白云金矿具有密切的成因联系:岩浆系统为成矿提供了能量和物质,双顶沟岩体主体相-矿区花岗斑岩脉-白云金矿矿体可能构成一连续的演化系列,而双顶沟岩体中心相和矿区的石英斑岩则是另一个系列。硅钾蚀变岩是白云金矿的最主要矿石类型和直接围岩类型,广泛发育特征的钾长石化。这种热液蚀变钾长石呈青紫色,主要为微斜长石和条纹长石,与石英、黄铁矿等矿物共生。矿石中热液钾长石与成矿前形成的钾长石(原生钾长石)物质成分差异较大,热液钾长石K20含量15.02～16.83%,Al2O3含量17.66～18.92%,Si02含量64.11～65.50%,原生钾长石K20含量46.56～66.39%,A1203含量19.02～36.79%,Si02含量15.02～16.83%,表明热液蚀变流体富集K、Si,在钾长石化水-岩反应中Al、Fe、Na、Mg等元素被带出。条纹长石的二长石温度计估算成矿温度为298℃C。黄铁矿矿物成分显示,Co/Ni平均值1.94,S/Se比值为0.12× 104～1.78× 104,平均值为0.5× 104,As-Co-Ni投图均靠近As-Co线,δ Fe-δ S参数等特征均说明黄铁矿为热液成因。综合分析认为,白云金矿为与印支期岩浆活动有关的岩浆热液型金矿。
[Abstract]:Baiyun gold deposit is located in the town of Baiyun Village Fengcheng Qingchengzi city in Liaoning Province, is a super large gold deposit in Qingchengzi Ore District in northern Liaodong. Baiyun gold deposit ore bodies mainly occur in the Gaixian formation of Liaohe Group schist formation, mineralization types are mainly silicon potassium altered rock type and quartz vein type, the control layer is obvious. This paper in the comprehensive arrangement of the former on the basis of the data, focusing on the geological characteristics of the deposit, and the surrounding rock of the mine slurry isotope chronology and geochemistry research, potassium feldspar and pyrite mineral composition, the genesis and ore-forming physicochemical conditions were analyzed and summarized, construct the magmatic hydrothermal metallogenic model. Baiyun gold deposit is lithologic interface stratiform and vein in the Gaixian formation of sillimanite biotite schist strata or sillimanite biotite schist and marble, directly or indirectly by the ductile shear zone and broken Take control of ore and quartz Ban Yan, Ban Yan granite veins close spatial relationship. The quartz vein type ore body and silicon potassium altered rock type ore bodies in the same tectonic magmatic hydrothermal system, fault zone of compressional environment, ore fluid infiltration metasomatism rock formation of silicon potassium altered rock type ore body, and when fracture occurrence is steep and the tensional environment, ore fluid along the fracture penetration formation of auriferous quartz vein type orebody. Mine magmatite mainly developed lithologic dikes, gabbro, diorite porphyrite and Ban Yan, Ban Yan and Ban Yan, granite, quartz two long Ban Yan, geological features show its invasion of macro an order of Ban Yan, Ban Yan, gabbro, granite, quartz diorite, and Ban Yan, two. Ban Yan U-Pb isotope dating of zircon indicate that mining dikes are mainly formed in the Proterozoic, Indosinian and Yanshan during the three period, the gabbro 1252.7 + 8.8Ma, 218.6 + 0.4Ma Ban Yan granite stone. The 218.5 porphyry diorite porphyrite + 2.9Ma, 229 + 1.0Ma, 164.4 + 0.4Ma. two long porphyry and lamprophyre in the southern area of the new age Ling area was 220 + 2.0Ma, double ditch Rock Center coarse granite age was 218.5 + 0.9Ma. double ditch rock from the center to the center can be divided into phase (coarse grain biotite granite), the main phase (two porphyritic biotite feldspar granite) and marginal facies (fine grained granite), the development of magma mixing, rock into mantle material involved in the process of rock. The geochemical characteristics of mine dikes show a variation of magma mixing. Mining area of granite porphyry and double ditch the rock body is porphyritic biotite granite two main characteristics of trace elements are similar; and the quartz porphyry rock center with dual ditch coarse grained biotite granite. Comprehensive analysis shows that the granite porphyry and quartz porphyry and biparietal Ditch rock might be the same magma system, and has a close genetic relation with magma system: Baiyun gold deposit provides energy and materials for the formation of the main phase, biparietal ditch rock mining of granite porphyry - Baiyun gold deposit may constitute a continuous evolution series, while the center ditch rock mining area and double quartz porphyry is another series of silicon potassium altered rock is the main ore types in Baiyun gold deposit and direct rock types, features extensive development of k-feldspathization. The hydrothermal alteration of potassium feldspar were purple, mainly for microcline and perthite, quartz, pyrite and other minerals symbiosis. The formation of hydrothermal potassium ore feldspar and premineral potassium feldspar (native potassium feldspar) material composition is different, the hydrothermal K feldspar K20 content of 15.02 ~ 16.83%, 17.66 ~ 18.92% Al2O3 content, Si02 content of 64.11 ~ 65.50%, the original potassium feldspar content of K20 is 46.56 ~ 66.39 %, A1203 content is 19.02 ~ 36.79%, Si02 content of 15.02 ~ 16.83%, showed that hydrothermal alteration fluid enriched in K, Si, k-feldsparization in water rock reaction in Al, Fe, Na, Mg and other elements were brought out. The two Perthitic feldspar ore thermometer to estimate the temperature of 298 DEG C. pyrite mineral composition display Co/Ni, an average of 1.94, the ratio of S/Se is 0.12 x 104 x 104 ~ 1.78, the average value is 0.5 * 104, As-Co-Ni investment plans are close to the As-Co line, the characteristics of delta Fe- Delta S parameters showed that pyrite hydrothermal genesis. Comprehensive analysis shows that the Baiyun gold deposit is a magmatic hydrothermal type gold deposit related to the Indosinian magma activity.

【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.51

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