浙江秦望山火山机构控矿特征及找矿方向

正本文依据近年来在绍兴平水—秦望山一带开展的大量地质找矿勘查工作,通过地质测量和物探激电测量厘定火山机构的形态和规模,解译矿致物探激电异常区,并对物探异常和火山通道复合部位开展土壤地球化学剖面测量和钻探验证工作。地球化学测量结果发现Au、Ag、Cu、Zn、Pb单元素异常均呈环状展布,与秦望山火山机构形态相吻合;钻孔验证结果,在受火山机构控制的流纹质凝灰岩     

采用综合探测技术，揭开秦皇陵地宫千古之谜

秦始皇陵是我国最大的帝王陵园。据古书记载，秦陵地宫墓室内珍宝无数。国家863计划项目之一，采用遥感和地球物理技术对秦始皇陵进行了探测，解开了秦陵地宫的位置、布局之谜。为进一步勘测地宫墓室内都有些什么东西，提议在不破坏墓室结构和原文物保存环境的前提下，采用岩土钻掘工程技术(孔或井巷)和影像技术(蛇形机械人等)综合探测方法，深入到地宫墓室里探查，为钻掘工程开拓地下考古工作提供了新思路。     

长江中下游地区铜地球化学块体时间属性——来自碎屑锆石LA-ICP-MS U-Pb定年的证据

利用水系沉积物地球化学组合数据在长江中下游地区共圈定出6个铜地球化学块体,首次利用碎屑锆石LA-ICP-MS U-Pb定年技术对地球化学块体的时间属性进行了研究.在铜矿床最为发育的Cu1、Cu2和Cu6三个块体内的碎屑锆石样品中清楚地识别出4个年龄峰值,分别对应古元古代、新元古代、早古生代和中生代.表明地球化学块体是跨时代存在的,物质来源于多期地质事件.新元古代和中生代地质体对研究区铜地球化学块体的形成也具有重要影响.研究还发现,成矿物质经后期的风化分散作用会进入到水系沉积物中,通过水系沉积物采样能够捕获成矿信息.     

地球化学块体的方法技术在山东金资源潜力预测中的应用

山东的化探扫面工作已经结束了13 a,积累了数十万的化探资料.作者尝试用地球化学块体的方法技术来挖掘这些资料的潜在价值.因此,对山东全省Au的资源潜力进行了预测,确定了圈定山东地球化学块体的下限值为2.5 ng/g,圈出了2个地球化学块体和数十个区域异常.统计计算了2个地球化学块体和8个区域异常的参数特征,计算出1 000 m厚岩块总的Au供应量为419 236 t,根据所确定的成矿率0.90%来预测500 m和1 000 m深度内这2个地球化学块体和8个区域异常所覆盖的15 631 km2的范围内的Au的资源潜力为1 249 t和2 522 t.     

地球化学块体法在埃塞俄比亚铜矿资源评价中的应用

低密度地球化学填图具有采样水系级别高、工作覆盖面积广阔的特征，可有效追溯具有高金属含量的地球化学块体。本次研究以埃塞俄比亚1∶100万低密度地球化学填图数据为基础，通过对原始水系沉积物中Cu测试数据处理后，应用迭代剔除的方法，计算得出Cu的异常下限值为37×10^-6。在此基础上，以37×10^-6、42×10^-6、47×10^-6、52×10^-6、59×10^-6、66×10^-6作为分级间隔，共圈定出地球化学块体3个、区域异常2个。通过参考相同成矿带中铜矿勘查研究程度较高的地球化学块体中已知铜矿床储量，计算出研究区的Cu块体成矿率为0.055%。本次以1 000 m岩块厚度估算出研究区内Cu的资源量为260万t。结合区域成矿地质条件分析，确定2号、3号、4号地球化学块体所在区域可作为开展进一步详细勘查工作的重点成矿远景区。     

甘肃夏河合作金富集区资源潜力分析——以金、银、锑地球化学块体为例

甘肃夏河-合作金富集区属秦岭造山带西段, 地质构造复杂, 出露地层主要有石炭系、二叠系、三叠系和古近系。燕山期、印支期中酸性岩浆侵入活动强烈, 断裂构造以走向逆断层为主, 次级断裂和层间破碎带发育。区内查明矿床点47处, 其中大型及以上规模金矿床3处, 中型3处, 小型41处, 显示了巨大的找金潜力。笔者应用"地球化学块体"理论和方法, 对金、银、锑地球化学块体进行圈定与内部结构剖分, 研究区域异常转变为局部异常、构建元素地球化学谱系树, 追索各子块体浓集成矿的轨迹。通过分析, 认为该区Au高值区面积大, 各层次块体浓集趋势明显, 形成Au地球化学省, 与Ag、Sb块体空间叠加组合, 计算出该块体500 m以浅金资源总量1 000 t,具备寻找大型-超大型金矿床的地球化学块体特征。区内成矿地质条件优越, 通过开展金资源潜力评价, 对本区的矿产资源评价、勘查工作部署具有重要指导意义。     

岩石化学元素丰度在地球化学块体研究中的意义

以Au、Ag、Cu、Pb、Zn、Sb、Hg、W、Sn、Mo、U、Cr、Ni、Co等14种成矿元素为例,利用中国东部不同构造单元的出露地壳和不同类型岩石的元素丰度阐明其在水系沉积物地球化学块体划分与研究中的意义.利用岩石元素丰度对地球化学块体进行研究,既可查明不同地球化学景观区水系沉积物地球化学块体的成因,又可为地球化学块体的研究对比提供条件.因此,应建立不同大地构造单元或不同地球化学景观区的岩石元素丰度并加强其与水系沉积物元素含量的对应关系的研究,这将会对地球化学块体的划分与推断解释提供重要的更加合理的依据.     

奇异值分解技术及地球化学块体方法在南黄岗—甘珠尔庙成矿带找矿中的应用

以黄岗—甘珠尔庙成矿带南部1∶20万化探扫面数据为基础,借助奇异值分解技术及地球化学块体方法,提取了该区地球化学综合异常及评价该区锡、锌矿的成矿潜力。通过研究得出如下结论:(1)不同方向构造的交汇部位、构造截切地球化学异常的部位或不同方向异常的叠加部位,是寻找钼、锡、钨、铜、铅、锌等矿床的有利地段;(2)区内多数矿床的赋存状态与二叠纪地层有密切的空间关系,特别是二叠纪地层与岩体的接触带或二叠纪地层与其他时代地层的接触带并发育断裂构造的部位;(3)研究区内共圈定了Sn地球化学块体1个,区域异常1个,局部异常8个;Zn地球化学亚块体1个,区域异常1个,局部异常7个。并以1 000 m作为块体厚度,计算了该区潜在锡资源量为211.92万t,潜在锌资源量为146.42万t;(4)通过对该区地球化学块体及异常结构的分析,并根据该区锡、锌矿的成矿条件来确定远景区的等级,本文共圈定了Sn成矿Ⅰ类远景区3个,Ⅱ类远景区4个,Ⅲ类远景区2个;Zn成矿Ⅰ类远景区3个,Ⅱ类远景区2个,Ⅲ类远景区2个。     

水系沉积物中的金属元素在中国东部不同构造单元的分布特征

中国东部全国区域化探扫面计划早已完成,积累了海量的水系沉积物数据.对分布在中国东部5个大地构造单元水系沉积物数据的金属元素的分布特征进行了统计,并与出露岩石地壳的岩石数据特征进行了对比,发现中国东部不同构造单元的出露岩石地壳的岩石成分决定着水系沉积物中金属元素的含量高低,两者之间存在着正相关的关系,不同构造单元同一金属元素具有不同的背景含量.水系沉积物中14种金属元素的含量比出露岩石地壳岩石中金属元素的含量富集,特别是低温热液元素,如Hg富集系数可高达13.6倍.另外,气候对金属元素从母质岩石中活化迁移分配到水系沉积物中的含量高低存在着影响,即低纬度地区的金属元素从母质岩石中活化迁移到水系沉积物中的量比高纬度地区多些,但这种影响因素相对于母质岩石成分的影响是居于次位的.     

地球化学土壤测汞法在断裂构造中的应用

本文简要介绍了土壤测汞法探测断裂构造及破碎带的方法原理,对异常的特征及断裂构造的判别准则进行了分析,通过实际测量结果进行了断裂构造的推断解释及其他方法的验证对比,表明地球化学测汞法在断裂构造勘察中具有较好的效果及前景。     

Mercury speciation in tailings of the Idrija mercury mine

Five hundred years of mercury (Hg) mining activity in Idrija, Slovenia caused widespread Hg contamination. Besides Hg emissions from the ore smelter, tailings have been found to be the major source of river sediment contamination. In the present study, solid phase binding forms and the aqueous mobility of Hg have been investigated in tailings of the Idrija Hg mine by means of a pyrolysis technique and aqueous Hg speciation. Results show that Hg binding forms differ with the age of the tailings due to the processing of different ores with different roasting techniques. In older tailings, the predominant Hg species is cinnabar (HgS), due to incomplete roasting, whereas in tailings of the 20th century the amount of cinnabar in the material decreased due to a higher efficiency of the roasting process and the increasing use of ores bearing native Hg. In younger tailings, metallic Hg (Hg⁰) sorbed to mineral matrix components such as dolomite and Fe-oxyhydroxides became the predominant Hg binding form in addition to unbound Hg⁰ and traces of HgO. Leaching tests show that in younger tailings high amounts of soluble Hg exist in reactive form. In older tailings most of the soluble Hg occurs bound to soluble complexes. It might be assumed that in the long term, matrix-bound Hg⁰ could be bound to humic acids derived from soils covering the tailings. This means that, despite the lower total Hg concentrations found in the younger tailings, the long-term risk potential of its mobile matrix-bound Hg⁰ is higher than that of older tailings bearing mostly immobile cinnabar.     

Mercury emission from the indigenous mercury smelting in Wuchuan mercury mining areas, Guizhou Province, China

Mercury smelting is one of the important anthropogenic atmospheric mercury emission sources. Small-scale mercury smelting activities with indigenous method which is considered illegal and forbidden by local government always extensively existed in the Wuchuan area, northeastern Guizhou Province, China. Because of the simple processes without any environmental protection, a large amount of mercury vapor released to the ambient air during the processing of cinnabar roasting. By determining mercury concentrations in mercury ore and smelting slag samples, a mass balance method was used to calculate mercury emission factors and annual mercury emission from indigenous mercury smelting in Wuchuan mercury mining areas, Guizhou Province, China. The mercury emission factors ranged from 6.9% to 32.1% with the recovery from 78.4% to 93.6% and the annual mercury emission was up to 3.7-9.6 metric tons. The results highlighted that the indigenous mercury smelting was one of the most important anthropogenic atmospheric mercury emission sources in this region.     

应用于水文与工程地质的化探新方法土壤吸附汞地球化学测量

介绍了化探土壤吸附汞地球化学测量方法的基本原理,指出土壤中汞异常具有多种来源,单一测汞方法不能区别其来源。测汞方法最重要的作用最准确指出汞气的迁移通道－基岩的断裂破碎带。因此该方法更适用于水文与工程地质勘查,特别是地下水勘查。     

环境汞调查报告

通过测定某部大院内土壤、大气环境中汞的含量、赋存状态,并对所得数据进行处理分析研究,得出某部大院环境中汞的分布特点与存在形式,从而对该地区汞的环境容量及其分布可能对人体健康产生的影响和危害有了一个较准确的认识与评价。     

云南腾冲热海高温地热水中汞的地球化学异常及其指示意义

汞是环境中典型有害组分,深部地热系统可能是环境中汞的重要来源之一,但当前地热成因汞的研究程度很低。本文以腾冲火山带热海水热区为研究区,开展了热泉中汞的水文地球化学研究。热海水热区内排泄的中性热泉含有异常高浓度的汞,但酸性热泉则绝大多数未检出汞。热海热泉中的汞与典型的岩浆来源组分氯相同,均主要来源于岩浆流体的混合。在中性热泉中,Hg(II)是汞的占优势地位的价态,Hg²⁺与不同形态硫化物的配合则是决定Hg(II)的形态分布的直接因素,但pH可通过控制水中硫化物的形态分布来影响Hg(II)的形态分布。Hg(II)不易挥发,故中性热泉中汞含量普遍较高;但酸性热泉中的汞受泉口氧化还原电位较高的影响,以Hg(0)为主要价态,且因Hg(0)易挥发而导致总汞含量极低。就中性热泉而言,其汞含量对水热区断裂分布有重要指示作用,原因为沿不同断裂上升的中性地热水经历的冷却方式不同,最终导致热泉汞含量也表现出显著差异。热泉汞含量对水热系统结构研究有借鉴意义。     

冷蒸气原子荧光法测量地球化学样品中痕量汞

用冷蒸气原子荧光法测量地球化学样品中痕量汞,对载气流量、试液酸度、硼氢化钾浓度等进行了试验。工作曲线线性范围为0～4μg/L,方法检出限为0.002 3μg/g,精密度RSD%为1.1~5.0。方法用国家一级地球化学标准物质中汞的测定,结果与标准值一致。     

贵州万山汞矿区稻田土壤汞的分布及污染特征

受历史汞矿开采活动影响,万山汞矿区稻田遭受了严重的汞污染.为了查明万山汞矿区稻田土壤的汞污染现状以及评估其环境质量改善情况,系统采集了受汞矿区影响的五条主干河流沿岸稻田土壤进行汞含量分析,评价总汞和甲基汞污染程度及其生态风险,并与2008 年以来该区域稻田土壤汞数据进行对比.结果表明,研究区稻田土壤的总汞含量为0.21...     

Mercury mobility at the Carson River Superfund Site, west-central Nevada, USA: Interpretation of mercury speciation data in mill tailings, soils, and sediments

The Carson River Superfund Site in west-central Nevada is an area of Hg-contaminated soil, sediment, water, air, and biola resulting from the amalgamation milling of Ag-Au ores of the Comstock lode worked approximately a century ago. In order to develop an understanding of the behavior, transport, and fate of Hg at this site, a technique was developed to estimate the proportions of total, elemental, exchangeable, organic, and sulfide Hg in soils, sediments, and tailings.Results of this analysis performed on active Carson River sediments indicate that Hg is selectively dissolved out of Hg-Au amalgam particles and subsequently adsorbed to fine-grained sediments which are then deposited in downstream, low-energy reaches of the Carson River and Labontan Reservoir. In the relatively more-reducing environment of the reservoir Hg appears to be converted, in large part, to relatively-insoluble HgS.The original elemental form of Hg released to the environment is the chemical form which is still dominant in most highly-contaminated soils, sediments, and tailings. Deeper, more-reducing soil horizons, however, appear to fix a significant portion of the Hg as HgS, analogous to the Lahontan Reservoir example described above. This fixation as HgS is documented to be largely limited to higher-sulfur areas where sulfide minerals from the Comstock ores increase the total sulfur concentrations of contaminated soils, sediments, and tailings.     

汉阳陵K21号外藏坑裂隙调查及稳定性研究

汉阳陵博物馆位于陕西省咸阳市,是我国也是全世界首座全封闭地下博物馆,其外藏坑的裂隙病害发育,严重危及坑壁和坑底文物安全,迫切需要保护和加固。以往对露天和半封闭环境下遗址病害及防治研究居多,而对全封闭环境下的研究鲜有报道。以汉阳陵K21号外藏坑为研究对象,首先通过现场调查确定裂隙数量和分布特征,在此基础上研究裂隙产生的原因并进行分类,通过数值模拟方法对坑壁稳定性及影响因素进行分析。研究结果表明：K21号外藏坑共53条裂隙,主要分布于南、北侧地表和坑壁,地表纵向裂隙为卸荷裂隙,地表横向裂隙为干缩裂隙,坑壁裂隙主要为构造裂隙;纵向卸荷裂隙是坑壁稳定性降低的主要原因,无论是地震、人为荷载还是裂隙进一步发育都将导致坑壁发生失稳。建议采用锚杆对坑壁进行加固,通过施加预应力对卸荷裂隙进行复位和预紧。该研究对馆藏遗址裂隙病害调查与保护具有重要的指导意义。     

Mercury in Western Canadian subbituminous coal—a weighted average study to evaluate potential mercury reduction by selective mining

Western Canadian subbituminous coal is mined using strip-mining methods. The coal is used to feed coal-fired power plants for electricity generation. Parameters that influence the mercury content of these coals include the occurrence and frequency of partings in the seam, weathering, and epigenetic mineralization. Most partings have higher mercury content than the coal layers in the same seam, with the single bentonite bed having the highest Hg content. However, some high ash components, such as sandy siltstone, do not follow this trend. The incorporation of the high mercury partings into the as-mined coal may increase the Hg content in the feed coal. Epigenetic mineralization may also increase the mercury content of coal, depending on the nature of the mineralization.Calculation of the weighted mean of mercury content for various combination of lithological components of a seam illustrates how these components influence the total mercury content of the seam. This approach also suggests how selective mining might be used to reduce mercury in “as-mined” coal.Results of weighted average calculations of mercury indicate that the thin lithological units with moderate mercury may not necessarily influence that overall weighted average of Hg for a seam. However, there can be exception, such as presence of thin (3.5 cm) bentonite parting with high mercury in a 94.5 cm seam that increased the mercury content of seam by 83.4%.