胶东大尹格庄金矿与夏甸金矿矿化特征对比研究

岩矿石主微量元素地球化学特征以及黄铁矿微量元素地球化学特征对大尹格庄金矿和夏甸金矿矿化规模和矿化特征的差异具有重要的指示意义。岩矿石主量元素迁移特征显示夏甸金矿矿化过程SiO2、Fe2O3的带入量较尹格庄多,表明夏甸金矿具有较好的硅化、黄铁矿化以及较强的金矿化。岩矿石微量元素迁移特征显示大尹格庄金矿成矿过程中Cu、Pb、Zn带入量以及CaO、MgO带入量较夏甸金矿少,表明大尹格庄金矿成矿期活动较弱,携带成矿物质较少。黄铁矿微量元素LA-ICPMS测试分析显示夏甸金矿黄铁矿Cu+Pb+Zn、Ga+In+Cd+Tl、As含量较大尹格庄金矿多,反映夏甸金矿热液活动性较强,金矿化较好。夏甸金矿从围岩到矿体SiO2、Fe2O3含量变化幅度较大以及不同成矿阶段黄铁矿中微量元素Cu+Pb+Zn、Ga+In+Cd+Tl、As变化幅度较大,显示矿化不太稳定,矿化规模较大尹格庄金矿小的特征。     

胶西北寺庄金矿床热液蚀变作用

胶东是我国最重要的金矿集区,其中"焦家式"破碎带蚀变岩型金矿是区内最重要的金矿床类型。寺庄金矿床位于胶东金矿集区焦家金矿田南部,是典型的"焦家式"金矿,沿NE向焦家断裂发育大规模的热液蚀变带,金矿体均产于这些蚀变带内。热液蚀变空间分带明显,距离焦家断裂由近到远向下盘依次发育黄铁绢英岩化、绢英岩化、钾长石化蚀变带。时间上,钾长石化为成矿前蚀变,绢英岩化和黄铁绢英岩化叠加在钾长石化蚀变之上,为成矿期蚀变,伴随金矿化。质量平衡计算表明:钾长石化过程,主量元素SiO_2、Al_2O_3、Fe_2O_3、FeO、MgO、CaO、Na_2O、P_2O_5,成矿元素Au、Ag,亲铜元素As、Hg、Sb、Bi和稀土元素均从玲珑黑云母花岗岩中迁出;而K_2O、MnO和Cu从流体中迁入玲珑黑云母花岗岩。绢英岩化和黄铁绢英岩化过程元素迁移行为高度相似,主量元素SiO_2、Fe_2O_3、FeO、MgO、CaO、K_2O、MnO,成矿元素Au、Ag,亲铜元素As、Hg、Cu、Sb、Bi和轻稀土元素均从流体中迁入钾长石化花岗岩,而主量元素Al_2O_3、Na_2O和重稀土元素均从钾长石化花岗岩中迁出。二长石温度计估算钾长石化蚀变形成的温度约为392～449℃。玲珑黑云母花岗岩(δEu=1.45)和钾长石化花岗岩(δEu=1.38)具有明显的Eu正异常,绢英岩(δEu=0.97)和黄铁绢英岩(δEu=0.93)具有轻微的Eu负异常,指示钾长石化发生于相对氧化环境下,而绢英岩化和黄铁绢英岩化发生于相对还原环境下。综合分析表明,成矿前高温、氧化、碱性流体作用于玲珑黑云母花岗岩形成大范围面状钾长石化蚀变;成矿期中低温、还原、弱酸性的流体与钾长石化花岗岩发生水岩反应,形成绢英岩化和黄铁绢英岩化,在此过程中硫化作用引起金硫络合物分解,导致金沉淀富集成矿。     

热液型金矿床围岩蚀变过程中元素迁移规律--以张家口地区东坪、后沟、水晶屯金矿为例

张家口地区东坪、后沟、水晶屯金矿围岩蚀变发育 ,主要的蚀变类型有钾长石化、硅化、黄铁矿化、绿泥石化等。通过蚀变岩常量元素、微量元素的定量计算发现 ,三个金矿床围岩蚀变过程中元素迁移、富集有明显的规律 ,即常量元素 (SiO2 、K2 O、FeO) ,亲硫元素 (成矿元素 :Au、Ag、As、Sb、Bi、Pb、Zn)明显富集 ,其它亲铜亲铁元素 (Cr、Co、Ni、Cu)略有富集。蚀变热液是一种来自深部的携带亲硫元素富硅的碱性流体     

胶东地区招平断裂带南段构造地球化学特征及找矿方向

胶东是我国最大的金矿集区,已探明金资源储量5000余吨。招平断裂带是胶东地区重要的控矿断裂,通常将其分为北、中、南三段,其中北段、中段目前都赋存大型-特大型金矿床,而南段仅有几个小型矿床。为揭示该断裂带的关键控矿因素,评估其南段成矿潜力,本文以招平断裂带南段为研究对象,通过元素相关性和聚类分析,确定成矿元素共生组合,进而圈定成矿有利地段。结果显示：Au、Bi、Pb、Ag等元素在绢英岩化碎裂岩、绢英岩化花岗质碎裂岩、碎裂状花岗岩中明显富集;糜棱岩中各元素含量与围岩大致相当,富集不明显。相关性分析和聚类分析显示,Au与Bi、Ag、Hg聚为一类,相关性好,是成矿的指示元素。与北段、中段相比,南段糜棱岩和构造片岩发育,南段由南向北韧性变性作用变弱,而脆性破碎逐渐变强。金矿的形成与脆性碎裂关系密切,韧性变形不利于金矿的形成。研究认为南段的北端、南端成矿条件好,具有较好的找矿潜力,而中部不利于成矿,找矿前景不大。     

新疆青河县库布苏破碎蚀变岩型金矿元素迁移特征与规律研究

本文以新疆库布苏金矿北矿带为研究对象,讨论了库布苏金矿床北矿带元素活动特征,成矿及伴生元素、主量元素、微量元素、稀土元素的质量迁移规律;根据稀土元素的质量迁移、地球化学特征,初步探讨了成矿流体的环境条件和来源问题;并依据元素迁移地球化学图研究了库布苏北矿带105勘探线剖面的元素质量迁移程度和范围。研究结果表明,赋矿闪长玢岩脉及围岩的元素发生明显的带入带出作用,元素迁移活动规律明显,成矿阶段发生明显带入有Au、As、Bi、Ag、Sb、K2O、Si O2,说明引起闪长玢岩脉和接触带围岩蚀变的流体中富含Au、As、K2O、Si O2等,导致这些带入元素向矿体迁移富集;发生明显带出的有Ba、Sr、Cu、Mg O、Na2O、Fe2O3、Ca O,说明Ba、Sr、Mg O、Na2O等受热液蚀变作用随流体迁出。矿区岩脉的稀土元素质量变化显著,发生明显的带入带出,岩脉交代蚀变前后的轻重稀土分馏均明显,蚀变后的岩脉轻重稀土分馏程度有减小趋势。赋矿闪长玢岩脉稀土元素配分曲线右倾,轻稀土富集,轻重稀土分馏明显,Eu强烈负异常,Ce弱负异常,说明库布苏金矿成矿流体条件应为较高温度和还原环境。从围岩与脉岩中元素的迁移程度和迁移范围可见,带入的成矿指示元素有As、W、Sb、Bi,带出的成矿指示元素有Mg、Na。     

招远大尹格庄金矿床微量元素特征及其意义

该文以山东招远大尹格庄金矿床中微量元素为研究对象,通过对矿床围岩、矿石等微量元素的研究,表明大尹格庄金矿围岩中微量元素以富含 Bi,Au,Pb,W,Ag,Sn 为特点,矿体和矿化体中元素组合为 Au,Ag,As,Sb,Hg,B, Cu,Zn,Bi,Mo,Mn,Co,Ni,W。在5个成矿阶段中,第二阶段与第三阶段微量元素的富集程度较明显,表现为 Au, Ag,As,Co,Bi,Cu,Pb,Zn 等的富集,成矿元素可分为2个分带序列,主成矿元素为 Au Ag Cu Pb Zn Bi 组合、头晕元素 As Sb Hg 组合和尾晕元素 Co Ni 组合。     

龙水金矿Ⅱ号矿化带的地球化学研究

根据龙水金矿Ⅱ号矿化带的地质特征和不同地质体中微量元素的分布特征、黄铁矿中微量元素的组合特征、稀土元素的分布模式、Rb-Sr法确定成矿年龄与锶同位素示踪、铅同位素研究及硫、氧、碳同位素组成的测定结果。论证了龙水金矿赋矿地层以富集Au、Ag、Cu、Pb、Zn、Sb、As等元素组合为特征；成矿物质可能主要来自花岗岩体，围岩提供了部分成矿物质，有大气降水加入；推测花岗闪长岩的源岩包括古老地壳物质；金矿形成于燕山中期。     

胶东焦家断裂带蚀变岩非镜像对称特征及其地质意义

焦家断裂蚀变带是胶东地区最重要的控矿构造之一。该断裂带控制的矿床是创立“焦家式”金矿理论的重要实例基础。目前,焦家断裂带累计探明Au资源储量超过1200 t,并且还在不断增加,展现了深部重要的勘查和研究价值。焦家断裂带控制的矿体主要赋存在主断面下盘,断裂带发育于花岗岩中时,上盘发育钾长石化花岗岩、绢英岩化花岗岩、黄铁绢英岩化花岗质碎裂岩、(黄铁)绢英岩质碎裂岩,下盘发育黄铁绢英岩质碎裂岩、黄铁绢英岩化花岗质碎裂岩、黄铁绢英岩化花岗岩和钾化花岗岩,蚀变类型在主断面两侧呈现对称分布特征。但是在岩性特征、结构构造、蚀变强度、化学成分等方面差异明显,表现出非镜像对称特征。上盘蚀变岩厚度大于下盘,下盘花岗岩的构造破碎程度比上盘花岗岩更严重;断裂带上盘黄铁矿含量低、一般无矿化显示,下盘黄铁矿含量高,出现金矿化;断裂带上盘的中生代花岗岩中韧性变形不发育,以脆性破裂为主,下盘发育明显的韧性变形;断裂带上下盘不同蚀变带的成矿元素Au,矿化剂元素S,成矿伴生元素Ag、Pb、Zn,亲石分散元素Ba、Sr以及主量元素Na2O、MgO含量具有差异性,指示焦家断裂带主断裂面两盘经历了不同的成矿作用过程,下盘花岗岩的热液蚀变作用与成矿作用的关系更为密切。依据焦家断裂带不同蚀变带元素的非镜像对称性特征,可利用上、下盘花岗岩和构造蚀变带的地球化学标志识别矿体或者不同蚀变带的位置,对认识“焦家式”金矿床的成因机制、预测深部成矿前景、指导深部找矿具有重要理论和实际意义。     

西秦岭寨上金矿床稀土元素和微量元素特征

寨上金矿的金矿石稀土元素特征与容矿岩石相似,与侵入岩(二长花岗岩)的差别较明显,说明寨上金矿床成矿与地层建造具有成因联系.矿化带中明显富集Au,Hg,As,Sb,Pb,Zn黄铁矿中Co/Ni平均值为0.27～1.5,矿体的Co/Ni平均值为0.33～0.40,说明成矿温度不高.从赋矿岩石到金矿体Co,Ni值有增加的趋势,说明从沉积成岩到成矿,成矿元素及微量元素有进一步的富集.     

新疆阿尔泰诺尔特地区金矿的成矿规律

阿尔泰诺尔特地区金矿主要赋存于石炭系,赋矿岩石主要是火山-沉积岩系,矿石有蚀变岩型和石英脉型两种:前者Au元素与凡、sb元素关系密切,含金矿物主要为毒砂;后者与Ag、Fe元素关系密切。金矿石的稀土元素特征、硫铅同位素与围岩一致,氢氧同位素组成显示成矿流体属于混合水,其中大气降水占很大比重。包痰体测温和成分分析表明,成矿流体属于低盐度,成矿温度为低温,结合冰长石的发现,本区金矿床属浅成低温热液矿床是明显的。同位萦年龄测定表明,金矿的主成矿期为燕山期。     

三维锚杆数值模拟方法研究

在现有几种锚杆数值分析方法的基础上,对考虑了浆体切向受力性态的三维锚杆单元理论及其应用进行了研究,编制了三维锚杆有限元计算程序,并结合例子对浆体锚杆的变形、应力规律进行了分析。计算结果显示了模型的可靠性和实用性。     

Geochemistry and origin of elements in some UK coals

Twenty-four UK coals ranging in rank with 4.6%–37.6% volatile matter were analysed for 46 major and trace elements. The samples were obtained from the UK Coal Bank and are representative of the major UK coal fields. The major element distributions are interpreted in terms of the mineralogical variations—quartz and kaolinite are largely responsible for the Si and Al, carbonates for Ca and Mg and pyrite for Fe. Also exerting an influence in some samples are siderite, Al-phosphate minerals and illite. Based on statistical relationships with the major elements, Rb, Cr, Th, Ce, Zr, Y, Ga, La, Ta, Nb and V are thought to be mainly present in the clay minerals, and As, Mo, Sb, Tl, Se and Bi and Pb are probably present in pyrite. Strontium and Ba are concentrated in a restricted number of samples related to the phosphate minerals. Germanium is the only element for which a major organic association can be demonstrated. Elements with an indirect association with the organic matter are Na, Cl, and Br in porefluids and possibly Te. The ash content is controlled mainly by the detrital input and the trace elements related to the ash content are therefore those elements associated with the clay minerals. Variations with rank would appear to be mainly related to the moisture content (porefluids). The trace elements associated with the quartz and clay minerals are thought to be dominantly detrital in origin. The non-detrital elements, essentially those contained in pyrite, are thought to have been incorporated in the depositional environment from waters with enhanced salinities through seawater ingress, hence there are positive relationships between S and trace element concentrations.     

Major and trace element geochemistry in upper Ganga river in the Himalayas, India

Chemical weathering and resulting water compositions in the upper Ganga river in the Himalayas were studied. For the first time, temporal and spatial sampling for a 1 year period (monthly intervals) was carried out and analyzed for dissolved major elements, trace elements, Rare Earth Elements (REE), and strontium isotopic compositions. Amounts of physical and chemical loads show large seasonal variations and the overall physical load dominates over chemical load by a factor of more than three. The dominant physical weathering is also reflected in high quartz and illite/mica contents in suspended sediments. Large seasonal variations also occur in major elemental concentrations. The water type is categorized as HCO₃^––SO₄^2––Ca²⁺ dominant, which constitute >60% of the total water composition. On an average, only about 5–12% of HCO₃^– is derived from silicate lithology, indicating the predominance of carbonate lithology in water chemistry in the head waters of the Ganga river. More than 80% Na⁺ and K⁺ are derived from silicate lithology. The silicate lithology is responsible for the release of low Sr with extremely radiogenic Sr (⁸⁷Sr/⁸⁶ Sr>0.75) in Bhagirathi at Devprayag. However, there is evidence for other end-member lithologies for Sr other than carbonate and silicate lithology. Trace elements concentrations do not indicate any pollution, although presence of arsenic could be a cause for concern. High uranium mobilization from silicate rocks is also observed. The REE is much less compared to other major world rivers such as the Amazon, perhaps because in the present study, only samples filtered through <0.2 m were analysed. Negative Eu anomalies in suspended sediments is due to the excess carbonate rock weathering in the source area.     

Chemical Analysis of Iron Meteorites by Inductively Coupled Plasma-Mass Spectrometry

Iron meteorites were analysed for nineteen siderophile and chalcophile elements by conventional inductively coupled plasma-mass spectrometry with the specific aim of demonstrating that this technique is an effective alternative to the more routine, yet complex, methodologies adopted in this field such as instrumental or radiochemical neutron activation analysis. Two aliquots of each meteorite sample, in the form of small shavings, were dissolved, one in 6 mol l^-1 HNO₃ and the other in aqua regia , and diluted to a final concentration of 1 mg sample per 1 ml of solution, without pre-concentrating the analytes. Nitric acid solutions were used for the determination of the elements Cr, Co, Ni, Cu, Ga, Ge and As; aqua regia solutions were analysed for the elements Mo, Ru, Rh, Pd, In, Sn, Sb, W, Re, Ir, Pt and Au. Samples were analysed by external calibration, carried out using synthetic multi-elemental solutions, and internal standardisation (with Be, Rb and Bi selected as internal standards). The results obtained from the analyses of nine geochemically well-characterized iron meteorites (Canyon Diablo, Odessa, Toluca, Coahuila, Sikhote-Alin, Buenaventura, Tambo Quemado, Gibeon, NWA 859) with widely variable chemical compositions are in good agreement with literature values for most elements. Detection limits were generally below the lowest concentration observed in iron meteorites. The most notable exception is for Ge, which cannot be successfully determined in the low-Ge meteorites of groups IVA, IVB and IIIF and a number of ungrouped irons. A test of the overall reproducibility of the adopted method, undertaken by repeatedly analysing the same Odessa IAB meteorite specimen, yielded relative standard deviations (1 s ) of between 1 and 6% for all elements except Cr (40%).     

浙江花岗岩类地球化学与地壳演化──Ⅰ.显生宙花岗岩类

浙江显生宙花岗岩包括加里东期、印支期和燕山期。用钻石U－Pb年龄确定了加里东、印支期花岗岩的存在，并讨论了各期花岗岩的主元素、稀土元素、微量元素和钛、锶、铅同位素组成的特征，以及它们的岩石成因。加里东和印支期花岗岩是元古宙基底岩石部分熔融的产物，燕山期花岗岩类是壳幔混合花岗岩。加里东和印支期两次构造运动较弱。大面积出露的燕山期花岗岩和火山岩意味着中生代发生了地壳增生。     

矿床中元素富集系数序列在找矿中的作用

本文介绍了确定矿床中元素K值(即富集系数)序列的方法;揭示了成矿元素、伴生元素和岩石组合元素具有明显不同的K值特征;阐明了K值序列在预测基本构造单元内的矿产类型,矿源层和成矿机理探讨中的应用及各种介质地球化学异常评价中的作用。     

ICP-AES法测定岩石、土壤和水系沉积物中22种元素

用盐酸、硝酸、氢氟酸和高氯酸溶解,ICP-AES法测定岩石、土壤及水系沉积物中22种 常量、次量和微量元素的分析方法。研究了不同的溶矿方法和条件:选择了最佳的分析谱线、观测 高度、背景扣除位置等条件。方法具有检出限低、精密度高及准确度好等特点,符合多目标区域地 球化学样品测试的要求,经国家一级岩石、土壤及水系沉积物标准物质分析验证,结果满意。     

浙江花岗岩类地球化学与地壳演化——Ⅱ.元古宙花岗岩类

浙江元古宙花岗岩类包括神功期（1．8－1．9Ga）和晋宁晚期（0．6—0．9Ga）。研究了浙江元古宙花岗岩类的主元素、微量元素、稀土元素和Rb、Sr同位素组成特征及岩石成因，探讨了浙江地壳的演化。浙江地壳形成于太古亩和元古宙，地壳增生的时期为2．6－2．7、0．8-1．1和0.1－0.12Ga。随时间演化浙江地壳组成有变化，但分异演化不明显。沿江-绍断裂分布的晋宁晚期慢源和壳幔混合中酸性岩是普宁期俯冲碰撞的证据。加里乐和印支期是两次规模不大的构造运动。     

新疆昭苏卡拉盖雷铜钴金矿区岩石地球化学特征

卡拉盖雷铜钴金矿是那拉提构造带内发现的首例以Cu为主,伴生Mo,Co,Au,Pb,Zn的火山岩型热液矿床.矿区内出露的地层主要为石炭系下统大哈拉军山组火山岩地层,矿区岩浆岩主要有花岗闪长岩、闪长岩和辉绿岩脉.通过火山岩地层和侵入岩样品的地球化学分析,认为区内大哈拉军山组是一套由玄武岩、安山岩、英安岩、流纹岩组成的连续亚碱性的火山岩系列,且以钙碱性系列为主;矿区钾长花岗岩属于准铝质—过铝质岩类,碱性系列,花岗闪长岩和闪长岩属于准铝质—过铝质岩类,钙碱性—碱性系列,基性侵入岩属于弱碱性—碱性系列.稀土元素特征显示中酸性侵入岩可能属于地壳重熔型花岗岩;基性侵入岩与基性火山岩来源一致.     

北淮阳晓天火山岩盆地片麻状花岗岩成岩年代学及地球化学特征

岩石的锆石U-Pb定年和主量、微量、稀土元素分析是研究侵入岩成岩时代、岩石成因的主要研究手段。本文在野外地质调查工作的基础上，采用X射线荧光光谱、电感耦合等离子体发射光谱、电感耦合等离子体质谱和LA-ICP-MS等技术对晓天火山岩盆地内杨三寨附近发现的片麻状钾长花岗岩进行相关地球化学分析。结果表明：该岩体主量元素以高硅、钾和钠，低铁镁钙磷为特征，其中SiO₂含量为65.86%~78.29%，Al₂O₃为10.89%~16.02%，MgO为0.17%~1.17%，K₂O为1.37%~6.44%，Na₂O为0.53%~6.50%，属于高钾钙碱性系列。微量元素方面，样品以亏损Nb、Sr、P和Ti，富集La、Ce、Nd和Zr为特征。稀土元素方面，含有较高的稀土元素（ΣREE=152.70~650.88μg/g），轻稀土富集重稀土亏损（LREE/HREE=6.77~20.64），多数具有较弱的负铕异常（δEu=0.29~1.15），铈异常不明显；稀土元素标准化曲线以右倾为特征。30个锆石点的²⁰⁶Pb/²³⁸U年龄分布于720~828Ma之间，加权平均年龄为776±11Ma （MSWD=2.1）。研究认为，盆地内新元古代片麻状钾长花岗岩的发现表明晓天盆地中心存在隆起，并不是之前研究认为的"斗"形的两边浅中间厚的盆地形态，这对该盆地的构造形态认识和进一步找矿具有重要的指导意义。