胶西北焦家—三山岛地区三维地质结构

本文利用2232个钻孔及矿山生产坑道资料,焦家—三山岛地区三维地质模型的建模方法和金矿床的三维空间特征,构建了地层、构造、侵入岩、蚀变带及1505个矿体模型,对主要控矿构造与矿体关系进行了三维空间分析,研究了主要矿体的空间分布规律,矿体浅部相对零散,向深部连为一体,规模上有扩大趋势,沿走向上和倾向上无矿间隔较为明显,矿体整体呈现分段富集规律。

胶东焦家金矿带招贤金矿床的原位黄铁矿热电性特征及找矿指示意义

胶东金矿集区是中国最大的黄金产地,焦家金矿带是重要的成矿亚带之一,产出了一系列超大型、大型金矿床,资源量占整个胶东地区的1/4,招贤金矿床为焦家带深部的大型金矿床。对招贤金矿床深部成矿潜力的评价可为焦家金矿带乃至胶东地区的金矿床深部找矿预测提供科学依据。文章选取了招贤金矿床3个钻孔6个不同标高的矿石样品,进行了详细的矿物学、成矿元素以及黄铁矿热电性特征研究。通过扫描电镜及半定量成分分析,鉴别了银金矿是主要的金矿物,常以包体的形式赋存于黄铁矿中或其裂隙中。金矿床围岩蚀变分带明显,显示了较强的矿化作用,其矿物共生组合和多阶段的成矿特征与胶东其他超大型金矿床相似。通过Au等成矿元素分析,笔者认为Au及其相关性高的元素具有规律性的垂向变化特征,元素沉淀具有垂向间断性。利用原位黄铁矿热电性测试方法,精准测定了黄铁矿热电性参数,并通过热电系数离散程度、热电性导型、形成温度、延伸指数等计算分析,综合讨论了金矿床成矿潜力,认为招贤金矿床及焦家金成矿带的深部具有较好的找矿前景。

成矿流体运移与就位及其构造控制机理:以胶东焦家金矿带为例

热液成矿系统的形成受控于构造运动引发的成矿流体运移和就位,构造是一级控矿因素,成矿流体的运移与就位则为构造控矿理论的核心。以流体压力差为主导、综合水力梯度和热传导等多种或单一主导因素驱动流体在围岩中由断层、裂隙和孔隙组成的输运通道中运移。流体在构造裂隙或孔隙中发生化学反应、流体混合和不混溶作用、流体沸腾都会导致流体物理化学性质发生变化,导致成矿物质沉淀;流体运移形式影响着矿化形式的表达,以管道流形式在宏观断层和裂隙中运移的流体以形成规模较大且矿化程度高的脉状矿体为主,而在围岩微米级裂隙和孔隙中广泛发育的渗透流多形成矿化品位稳定、规模中等的细脉-浸染状矿体。构造变形与流体压力、应力状态之间的动态耦合导致矿体的时空定位,断层阀-泵吸机制是解释造山型金成矿作用最具代表性的构造-流体耦合成矿动力学模型。胶东焦家金矿带中矿床的形成与分布受到焦家断裂带上一、二、三级断裂构造的联合控制:压剪性的焦家断裂为一级控矿构造,控制了广泛的以绢英岩化为主的热液蚀变作用和破碎带蚀变岩型金矿体的形成与就位;在其下盘张剪性的望儿山断裂为二级控矿构造,热液蚀变相对较弱,发育过渡型金矿体;三级控矿构造为以鲍李断裂为主的数十条张剪性断裂和节理系,蚀变-矿化程度最弱,主要控制石英脉型金矿体的产出。寺庄金矿床矿体三维几何学结构研究表明从I号到Ⅲ号矿体群的形态扁平程度增加,说明成矿流体输运方式由渗透流向管道流的空间演变,矿体产状差异则反映成矿流体运移方向也发生了变化。进一步研究需融合多学科方法和成果,特别是深入剖析显微-超显微变形组构与成矿流体行为耦合关系,构建逼近实际的多尺度构造-流体耦合成矿模型,揭示热液成矿系统形成的精细过程和机理。

胶东三山岛金矿床巨斑花岗岩的形成时代、成因及对金成矿的启示

胶东地区三山岛金矿床的主要赋矿围岩是中生代玲珑花岗岩和郭家岭花岗岩。通过对三山岛巨斑花岗岩进行岩相学、岩石地球化学和锆石U-Pb同位素年代学等研究,分析其地球化学类型、形成时代、岩浆源区及成因,讨论了成岩与成矿的关系。岩石地球化学特征表明:三山岛巨斑花岗岩的SiO_(2)、Al_(2)O_(3)和全碱(Na_(2)O+K_(2)O)含量较高;铝饱和指数A/CNK为1.34,属过铝质—钙碱性系列岩石;稀土元素含量较低,轻稀土相对富集,重稀土相对亏损;岩石富集Rb、Sr、和Ba等大离子亲石元素,亏损Ta、Nb、P和Ti等高场强元素;岩石地球化学特征与富钠花岗岩和年轻的TTG(<3 Ga)相似。巨斑花岗岩的锆石U-Pb加权平均年龄为(127.05±0.41)Ma,属于早白垩世郭家岭期花岗岩。岩石中金丰度值较早前寒武纪变质岩系明显降低。综合研究认为,巨斑花岗岩是下地壳酸性岩浆与少量幔源基性岩浆混合作用的结果,形成于太平洋板块俯冲和华北克拉通破坏背景下的伸展构造环境,岩体中的钾长石巨晶是岩浆期后钾化作用的结果;具有较高背景金丰度的早前寒武纪变质基底岩石部分熔融过程中,地球化学元素重新调整,金质被活化、迁移,形成富金流体库,并产生贫金花岗岩;花岗岩快速侵位和地壳强烈隆升产生的拆离断层系统,以及钾化作用导致岩石体积膨胀而破裂,为成矿流体聚集和矿化富集提供了良好的物理圈闭空间。

胶东三山岛断裂带金矿床蚀变矿物勘查标识

三山岛断裂带蚀变岩型金矿床控矿断裂产状变化部位含矿性存在差异,使得矿体不连续,勘查标识不明确。通过对三山岛北部海域金矿床30号勘探线的多个钻孔和三山岛井下坑道进行系统编录和样品采集,研究矿物共生组合与矿脉之间的穿切关系。研究表明:北部海域金矿床可划分为4个成矿阶段,即石英—黄铁矿—钾长石阶段(Ⅰ)、石英—黄铁矿—黄铜矿—自然金阶段(Ⅱ)、石英—黄铁矿—方铅矿—闪锌矿—自然金阶段(Ⅲ)和贫矿菱铁矿—方解石阶段(Ⅳ),其中Ⅱ和Ⅲ阶段是金的主要成矿阶段。利用短波红外光谱对控矿断裂含矿和贫矿部位样品进行分析,发现蚀变矿物组成、Al-OH吸收峰位和结晶度(IC)等存在明显差异,高的Pos2200和IC值与金矿体之间存在明确的正相关关系。对各钻孔的品位数据进行统计分析后,引入机器学习算法进行分析,强调IC值具有更高的权重影响。黄铁矿微量元素研究显示:As、Pb、Bi、Te和Sb等元素与Au元素含量之间具有显著正相关性。由此,基于断裂产状、短波红外光谱指标和黄铁矿元素含量等变化情况,建立了全新的勘查标识,对实际找矿勘查工作具有指导意义。

多元成矿规律在寺庄矿区探矿中的研究及应用

寺庄金矿床位于焦家金矿带南段,为了尽快增加矿山地质储量,解决不断扩产带来的供矿紧张这一日益突出的问题,迫切需要成矿理论创新,以科技攻关成果带动地质找矿取得新突破。在综合分析研究寺庄金矿床成矿规律的基础上,充分考虑隐伏矿体成矿特征,主要从“倒N形”、“尖灭再现”、“菱形格子”三个成矿规律入手,构建找矿预测模型,先后实施探矿验证工作。通过多元成矿规律的组合研究,形成了“倒N形”适合复杂Ⅲ号矿体、“尖灭再现”适合Ⅰ号矿体及薄细矿脉、“菱形格子”适合主断裂斜交构造控矿的成矿规律。

化处镇焦家村巩固脱贫攻坚成果与乡村振兴衔接的路径研究

该文以化处镇焦家村为调研对象,积极响应国家全面推进乡村振兴的战略要求,在全面打赢脱贫攻坚战并取得丰硕的脱贫攻坚成果基础上,探索焦家村在巩固脱贫攻坚成果和乡村振兴衔接过程中的发展现状。通过实地调研发现焦家村目前存在产业发现支撑力度不足、区位优势未充分发挥、缺乏特色旅游业等问题,并就亟需解决问题提出完善产业发展支撑保障、优化资源配置、打造特色旅游业等建议,以期为全面推进乡村振兴注入不竭动力。

The Kiloton Class Jiaojia Gold Deposit in Eastern Shandong Province and Its Genesis

The recent deep prospecting results in the Jiaojia area of Eastern Shandong Province indicate that the Jiaojia ore field composed of several individual gold deposits as previously suggested is actually an ultra-large gold deposit.This deposit covers an area of ～40 km2,and shows a structural control by the Jiaojia fault and its secondary faults.Gold orebodies generally occur along the same mineralization-alteration belt,and the main orebodies intersect with each other or exhibit a parallel or overlapping distribution.This deposit＇s reserves are estimated to be 1,200t of gold,being the first gold deposit of more than 1000t gold reserves in China.The No.Ⅰ-1 orebody in the Shaling-deep Sizhuang ore blocks holds gold reserves greater than 350 t,or 29 percent of the total reserves,followed by the No.Ⅰ orebody in Matang-Jiaojia ore blocks with exceeding 150t gold reserves.This deposit mainly occurs in the footwall of the Jiaojia fault,and presents zoned patterns in mineralization,alteration and structures.The strongly mineralized zones agree with strongly altered and tectonically fractured zones.These orebodies display strataform-like,veinlike or lenticular shapes,and generally show characteristics of pinching out and reappearing,branching and converging,expanding and shrinking.The orebodies commonly occur along positions where the fault strike changes and in gentle locations with dips changing from steep to gentle.The main orebodies are parallel to the main plane of the orecontrolling fault,and tend to be gentle from the surface to the deep.The orebodies mainly plunge to the southwest,with plunge angle of 45°-606° Orebodies near the main plane of the ore-controlling fault have more gold resource than those away from main fault zone.The slant depth of orebodies is generally larger than the length along its strike direction; orebodies become thick and gold grades become low from the shallow area to the deep area.Ore-forming fluids are H2O-CO2-NaCl±CH4 type with medium-temperature and moderate to low salinity.Sulfur isotopic values （δ34SCDT） for gold ores range between 11.08‰ and 12.58‰,indicating mixed sulfur sources; hydrogen isotopic values （δDVSMOW） range from-83.68‰ to-116.95‰ and oxygen isotopic values （δ18OV-SMOW） range between 12.04‰ and 16.28‰.The hydrogen and oxygen isotopes suggest that ore-forming fluids originated from primary magma,and mixing with a large amount of atmospheric water during the late stage.The Eastern Shandong Province gold deposits are associated with magmatic activities which have mantle crust-mixed source,and also share some similarities with orgenic and epithermal hydrothermal golddeposits.Because Eastern Shandong Province gold deposits with unique metailogenic features and formation setting which are different from other gold deposit types in the world,we call it the Jiaojiatype gold deposits.The kiloton class Jiaojia gold deposit is related to fluid activities,extension and detachment resulted from thermal upweiling of magmas.The strong magmatic activities in the middle to late stage of early Cretaceous in Eastern Shandong Province lead to active fluids,and provided abundant ore-forming materials for gold depsoits.Moreover,many extensional structures resulting from crustal extension provided favourable space for orebody positioning.

He–Ar Isotopic Tracing of Pyrite from Ore-forming Fluids of the Sanshandao Au Deposit, Jiaodong Area

The Sanshandao Au deposit is located in the famous Sanshandao metallogenic belt,Jiaodong area.To date,accumulative Au resources of 1000 t have been identified from the belt.Sanshandao is a world-class gold deposit with Au mineralization hosted in Early Cretaceous Guojialing-type granites.Thus,studies on the genesis and ore-forming element sources of the Sanshandao Au deposit are crucial.He and Ar isotopic analyses of fluid inclusions from pyrite(the carrier of Au)indicate that the fluid inclusions have 3 He/4 He=0.043–0.21 Ra with an average of 0.096 Ra and 40 Ar/36 Ar=488–664 with an average of 570.8.These values represent the initial He and Ar isotopic compositions of ore-forming fluids for trapped fluid inclusions.The comparison of H–O isotopic characteristics combined with deposit geology and wall rock alteration reveals that the ore-forming fluids of the Sanshandao Au deposit show mixed crust–mantle origin characteristics,and they mainly comprise crust-derived fluid mixed with minor mantle-derived fluid and meteoric water during the uprising process.The ore-forming elements were generally sourced from pre-Cambrian meta-basement rocks formed by Mesozoic reactivation and mixed with minor shallow crustal and mantle components.

Geology and mineralization of the Sanshandao supergiant gold deposit(1200 t)in the Jiaodong Peninsula,China:A review

The Jiaodong Peninsula in Shandong Province,China is the world’s third-largest gold metallogenic area,with cumulative proven gold resources exceeding 5000 t.Over the past few years,breakthroughs have been made in deep prospecting at a depth of 500‒2000 m,particularly in the Sanshandao area where a huge deep gold orebody was identified.Based on previous studies and the latest prospecting progress achieved by the project team of this study,the following results are summarized.(1)3D geological modeling results based on deep drilling core data reveal that the Sanshandao gold orefield,which was previously considered to consist of several independent deposits,is a supergiant deposit with gold resources of more than 1200 t(including 470 t under the sea area).The length of the major orebody is nearly 8 km,with a greatest depth of 2312 m below sea level and a maximum length of more than 3 km along their dip direction.(2)Thick gold orebodies in the Sanshandao gold deposit mainly occur in the specific sections of the ore-controlling fault where the fault plane changes from steeply to gently inclined,forming a stepped metallogenic model from shallow to deep level.The reason for this strong structural control on mineralization forms is that when ore-forming fluids migrated along faults,the pressure of fluids greatly fluctuated in fault sections where the fault dip angle changed.Since the solubility of gold in the ore-forming fluid is sensitive to fluid pressure,these sections along the fault plane serve as the target areas for deep prospecting.(3)Thermal uplifting-extensional structures provide thermodynamic conditions,migration pathways,and deposition spaces for gold mineralization.Meanwhile,the changes in mantle properties induced the transformation of the geochemical properties of the lower crust and magmatic rocks.This further led to the reactivation of ore-forming elements,which provided rich materials for gold mineralization.(4)It can be concluded from previous research results that the gold mineralization in the Jiaodong gold deposits occurred at about 120 Ma,which was superimposed by nonferrous metals mineralization at 118‒111 Ma.The fluids were dominated by primary mantle water or magmatic water.Metamorphic water occurred in the early stage of the gold mineralization,while the fluid composition was dominated by meteoric water in the late stage.The S,Pb,and Sr isotopic compositions of the ores are similar to those of ore-hosting rocks,indicating that the ore-forming materials mainly derive from crustal materials,with the minor addition of mantle-derived materials.The gold deposits in the Jiaodong Peninsula were formed in an extensional tectonic environment during the transformation of the physical and chemical properties of the lithospheric mantle,which is different from typical orogenic gold deposits.Thus,it is proposed that they are named“Jiaodong-type”gold deposits.

Structural geochemistry of gold mineralization in the Linglong-Jiaojia district, Shandong Province, China

The Linglong-Jiaojia district is one of the most important regions containing gold deposits in China. These gold deposits can be divided into: a) the pyrite-gold-quartz vein type (Linglong type), which is controlled by brittle-ductile to ductile deformation structures, and b) the alteration-zone type (Jiaojia type), characterized by small veinlets, or the disseminated type recognized in brittle shear zones. Lode gold deposits in the Jiaojia area occur in NE brittle fracture zones, formed in a dominantly simple shear deformation regime, mainly in thrust attitude with a minor sinistral strike slip component. In the Linglong area, the lode gold deposits are located at the intersection of three types of structures: NNE and NE brittle-ductile fault zones and the ENE ductile reverse shear zone in the south of the area. The structural characteristics of these brittle shear zones are consistent with a tectonic NNW-SSE principal stress field orientation. Similar stresses explain the ENE Qixia fold axes, the Potouqing and several other ENE reverse ductile shear zones elsewhere in the region, the Tancheng-Lujiang fault zone and its subsidiaries in the vicinity of the Linglong-Jiaojia district, as well as the southern ENE suture zone north of Qingdao. Therefore these structural systems occurred as part of different major tectonic events under NNW-SSE compression principal stress fields in the area. Gold deposits are hosted in smaller-scale structures within the brittle fault zones and brittle-ductile shear zones. Although ore bodies and, on a smaller scale, quartz ore veins often seem to be randomly oriented, it is possible to explain their distribution and orientation in terms of the simple shear deformation process under which they were developed. The progressive simple shear failure is characterized by various fracture modes (tension and shear) that intervene in sequence. The tension and shear fractures are influenced by the stress level (depth of burial beneath the paleosurface) in their structural behavior, show variable dilatancy (void openings) and extend on all scales. By making use of these characteristics, a progressive failure analysis can be applied to predicting the shape and extent of ore bodies as well as the styles of mineralization at any given location.

Deep gold mineralization features of Jiaojia metallogenic belt,Jiaodong gold Province:Based on the breakthrough of 3000 m exploration drilling

Recently,continuous breakthroughs have been made about deep gold prospecting in the Jiaodong gold province area of China.Approximately 5000 t of cumulative gold resources have been explored in Jiaodong,which has thus become an internationally noteworthy gold ore cluster.The gold exploration depth has been increased to about 2000 m from the previous<1000 m.To further explore the mineralization potential of the Jiaodong area at a depth of about 3000 m,the Shandong Institute of Geological Sciences has drilled an exploratory drillhole named“Deep drillhole ZK01”to a depth of 3266 m.Hence,as reported herein,the mineralization characteristics of the Jiaojia metallogenic belt have been successfully documented.ZK01 is,to date,the deepest borehole with an gold intersect in China,and constitutes a significant advance in deep gold prospecting in China.The findings of this study further indicate that the depth interval of 2000 m to 4000 m below the ground surface in the Wuyi Village area incorporates 912 t of inferred gold resources,while the depth interval of 2000 m to 4000 m below the surface across the Jiaodong area possesses about 4000 t of inferred gold resources.The Jiaojia Fault Belt tends to gently dip downward,having dip angles of about 25°and about 20°at vertical depths of 2000 m and 2850 m,respectively.The deep part of the Jiaojia metallogenic belt differs from the shallow and moderately deep parts about fracturing,alteration,mineralization,and tectonic type.The deep zones can generally be categorized from inside outward as cataclastic granite,granitic cataclasite,weakly beresitized granitic cataclasite,beresitized cataclasite,and gouge.These zones exhibit a gradual transitional relation or occur alternately and repeatedly.The mineralization degree of the pyritized cataclastic granite-type ore in the deep part of the Jiaojia metallogenic belt is closely related to the degree of pyrite vein development;that is,the higher the pyrite content,the wider the veins and the higher the gold grade.Compared to the shallow gold ores,the deep-seated gold ores have higher fineness and contain joseite,tetradymite,and native bismuth,suggesting that the deep gold mineralization temperature is higher and that mantle-sourced material may have contributed to this mineralization.ZK01 has also revealed that the deep-seated ore bodies in the Jiaojia metallogenic belt are principally situated above the main fracture plane(gouge)and hosted within the Linglong Granite,contradicting previous findings indicating that the moderately shallow gold ore bodies are usually hosted in the contact zone between the Linglong Granite and Jiaodong Group or meta-gabbro.These new discoveries are particularly significant because they can help correct mineralization prospecting models,determine favorable positions for deep prospecting,and improve metallogenic prediction and resource potential evaluation.

山东焦家金矿田锶、铅同位素特征及其地质意义

焦家金矿田是胶西北地区重要的金矿产地,金矿类型以破碎带蚀变岩型为主,其成矿物质来源及成矿地质体尚存争议。采取了焦家金矿田深部样品,分析其同位素特征,研究成矿物质来源,探讨金矿成矿地质体。焦家金矿田金矿石黄铁矿87Sr/86Sr=0.711653~0.73245,按焦家金矿田平均成矿年龄120 Ma返算的(87Sr/86Sr)i的值,其范围0.710752~0.711986,与郭家岭花岗岩较为接近。焦家金矿田金矿石黄铁矿208Pb/204Pb=37.683~38.103,207Pb/204Pb=15.43~15.547,206Pb/204Pb=17.04~17.44。焦家金矿田金矿体铅为地幔和下地壳的混合源。郭家岭型花岗岩与焦家金矿田金矿形成时间相近,分布空间相依,与金矿体同位素组成接近,成因上有密切联系,是金矿的成矿地质体。

胶东焦家金矿床成矿过程热液蚀变化学反应数值模拟

焦家金矿床是胶东金矿集区中典型的破碎带蚀变岩型金矿床,存在明显的蚀变分带特征,然而,热液蚀变分带的形成条件及金沉淀化学反应的空间位置尚不够明确。本文利用TOUGHREACT软件对焦家金矿床含矿热液与围岩化学反应进行了模拟,旨在定量探讨该矿床热液蚀变过程。通过分析含矿热液与围岩发生的化学反应,构建热液蚀变成矿概念模型,模拟计算不同温压条件下成矿流体组分化学平衡浓度以及pH值的变化,研究成矿过程热液蚀变矿物的溶解与沉淀机制。模拟结果显示, Au+的化学平衡浓度在温度从280℃降至180℃的过程中呈明显下降趋势, Fe2+化学平衡浓度与Au+呈现相似的变化趋势,表明金矿物最佳成矿温度范围为180~280℃,成矿流体中Fe2+与[Au(HS)2]-络合物发生置换还原反应,促使金沉淀析出;不同温度和压力条件对成矿元素化学平衡浓度变化的影响表明,温度是控制金沉淀化学反应的关键因素,压力影响相对较小;而pH值模拟结果表明,热液蚀变反应过程中成矿流体pH值升高,成矿环境从酸性逐渐转变为中性、碱性,与传统地质手段分析结果一致,验证了模拟结果的有效性。上述研究结果表明,在温度驱动力作用下,成矿流体沿断裂侧向运移与围岩持续叠加的蚀变作用,形成了蚀变分带;在紧靠断裂带下盘的黄铁绢英岩化带,由于易发生多种蚀变的叠加以及成矿温度、pH值的变化,有利于金的沉淀富集。

胶东焦家金矿田“三位一体”找矿预测地质模型与深部找矿示范

焦家金矿田是胶东地区金矿最富集的三大金矿田之一。为开展焦家金矿田深部找矿预测工作,在焦家金矿田深部调查工作总结的基础上,运用勘查区找矿预测理论构建了找矿预测地质模型。结果显示,早白垩世郭家岭型花岗岩是焦家金矿田的金矿成矿地质体;成矿构造系统为焦家断裂构造系统,成矿结构面主要包括主断裂面、次级断裂面、裂隙面等;热液蚀变类型主要有钾长石化、黄铁矿化、绢英岩化、硅化、碳酸盐化等。以勘查区找矿预测地质模型为指导,开展了深部找矿预测,圈定了深部找矿靶区2处,经钻探验证均取得了较好的见矿效果,开拓了深部找矿空间。

焦家式蚀变岩型金矿床热液蚀变成因:磷灰石矿物学、年代学和地球化学约束

胶东是我国最大的金矿集中区,累计探明金资源量5000余吨,焦家式蚀变岩型金矿床提供了80%以上的金资源量,钾长石化和黄铁绢英岩化蚀变是该类矿床的重要找矿标志,但对其成因与形成时限缺乏有效约束。为探究两类蚀变的成因并限定其形成年龄,本文对典型蚀变岩型金矿床中钾长石化花岗岩与黄铁绢英岩化碎裂岩进行锆石和磷灰石LA-ICP-MS U-Pb地质年代学、磷灰石微区原位微量元素地球化学测试。结果表明,钾长石化玲珑花岗岩的锆石U-Pb年龄为155.0±1.1Ma~155.8±1.3Ma,代表了其岩浆侵位年龄;钾长石化玲珑花岗岩蚀变弱的A1型磷灰石没能得到有效年龄,而蚀变较强的A2型磷灰石U-Pb年龄为146±7Ma~147±6Ma,代表了钾长石化蚀变作用发生的时间;黄铁绢英岩化碎裂岩蚀变较弱的B1型磷灰石数量较少未形成协和年龄,强蚀变B2型磷灰石U-Pb年龄为125±6Ma,代表了黄铁绢英岩化蚀变作用发生的时间。A1型磷灰石的稀土配分曲线与未蚀变玲珑花岗岩较为一致,A2型磷灰石显示更高的轻稀土含量和更明显的Eu负异常,随着钾长石化蚀变程度增强,La/Yb比值逐渐增大,Sr含量和Sr/Y比值同步降低,暗示蚀变流体相对富轻稀土,蚀变过程磷灰石的Sr被活化迁移;B1型磷灰石的稀土配分曲线与未蚀变玲珑花岗岩相似,B2型磷灰石和未蚀变郭家岭花岗岩较为一致,轻重稀土分异明显,且Eu异常不明显,在黄铁绢英岩化蚀变过程中Sr含量、Sr/Y比值和La/Yb比值显著增高。本文认为与焦家式蚀变岩型金矿成矿相关的蚀变作用与区域岩浆作用有关,晚侏罗世玲珑花岗岩的自交代作用形成了钾长石化蚀变,早白垩世郭家岭花岗岩分异的热液沿区域性断裂迁移,导致断裂带内发生黄铁绢英岩化。

三山岛金矿海底开采井下沉降特点及影响因素浅析

三山岛金矿新立矿区是我国首例实施海底开采的金属矿山。为了研究新立矿区井下矿体围岩变形破坏特征,以与矿体走向垂直的55号勘探线为监测剖面,通过布设井下四等水准监测系统,对55号勘探线剖面内不同深度开采中段巷道顶板围岩的垂直位移进行了长期监测。分析结果表明:(1)海底不同深度各中段矿体开采引起的变形均表现为对上盘岩体的影响范围大,而对下盘岩体影响范围小,越靠近矿体(或控矿断层F_(1))部位,顶板围岩的下沉量越大;(2)各中段的累积沉降量曲线总体上表现为不对称漏斗形,其中较浅部的-200 m中段与-240 m中段累积沉降量曲线底部较为平缓,呈近似“锅”状,而深部的-320 m、-400 m、-480 m和-600 m中段沉降曲线呈“漏斗”状;(3)新立矿区矿体厚度、开采深度、开采强度、围岩岩性、围岩岩体结构以及充填效果是影响海底倾斜矿体开采围岩变形的因素,其中,矿区内控矿断层F_(1)的存在直接影响围岩变形曲线的形态。

三山岛金矿地面沉降特征及原因分析

地面沉降作为一类缓变型地质灾害,可对人们的生产生活造成重要影响。三山岛金矿自2012年9月在地下采矿影响范围内建立全球定位系统(GPS)并监测地面沉降以来,监测到明显的地面沉降现象。分析结果表明:(1)多年来,研究区内地面沉降范围变化趋势较一致,沉降盆地分布于矿体的上盘区域,沉降盆地的形态由最初的近似圆形发展到后期的椭圆形,并沿矿体上盘方向发展演化;(2)沉降等值线在靠近F_(1)控矿断裂一侧较密集,而在远离F_(1)断裂一侧较稀疏,随着时间的推移,沉降中心区域的累积沉降值越来越大,根据累积沉降曲线斜率的变化情况,可将累积沉降量曲线划分为3个阶段;(3)三山岛金矿地面沉降的采矿影响因素主要有矿体赋存形态、埋深、地应力环境、断层活动和充填采矿方式等,而非采矿影响因素可归纳为人为社会因素,即由于采矿经济发展,建筑物增多,以及抽排地下水等,致使地面沉降现象也会有所加重。

太湖三山岛湿地生态修复工程

大型浅水型湖泊受风浪扰动易造成底泥悬浮,水体透明度低,水生植被难以生长。针对太湖滨岸带存在的问题,运用系统生态学研究方法,开展多层生态围隔系统修复及植被恢复设施研究,提高了水体透明度,解决了水生植物恢复的难题,有效地提升了太湖三山岛湿地生态系统的功能。

三山岛金矿井下电机车自动驾驶系统设计

电机车是金属矿山矿石运输的主力装备,用于井下运输大巷和地面的长距离运输,智能化和自动化是电机车未来的发展趋势。传统的有人驾驶电机车进行作业时,劳动强度大且存在一定的安全风险。在恶劣工况下如何提高电机车工作效率、降低安全风险,是制约井下生产的瓶颈问题。利用自动控制、高速低延时网络、优化调度等技术,构建了三山岛金矿电机车自动驾驶系统,实现了智能化矿石运输。电机车是矿山智能化的重要装备支撑,可以提高矿石运输效率和作业安全性,具有良好的安全效益和经济效益。