陕西双王含金角砾岩地质特征及成因初探

双王金矿含金角砾岩为水力压裂成因角砾岩。认为该水压角砾岩体是深源富碱含金流体在泥盆系一套热水沉积的富钠质岩系中发生水力压裂作用形成的。早期共轴递进挤压使能干性的富钠质岩系与非能干性的富泥质岩系发生构造透镜石香肠化；晚期的非共轴递进剪切使早期在透镜体中心形成的构造裂隙由剪性转化为张性，并产生巨大的压力降使深部的流体在富钠质岩系中沿裂隙发生水力压裂作用，从而形成双王水力压裂含金角砾岩。     

滇西兰坪盆地金顶铅锌矿盐构造发育特征及其与成矿关系

滇西兰坪中新生代盆地广泛发育盐岩层系。通过对金顶超大型铅锌矿区的露天采厂和地下采坑的最新野外调查及大量钻孔资料的综合分析,研究区盐岩层系具有多期、多阶段运动的特点,厚度分布极不均一,它们作为区域推覆构造作用的滑脱层,对盐上层构造变形起着重要控制作用,形成一系列储矿构造。研究表明,矿区盐构造主要包括盐枕、盐背斜、盐焊接、盐穿刺、盐推覆、盐岩滑脱-断层相关褶皱组合等多种盐构造变形样式。这些盐构造的形成演化及变形机制主要受到推覆挤压缩短作用、基底断层作用和塑性流动汇聚作用、盐下和盐上层断裂滑脱作用等控制,主要沿推覆断裂构造带呈串珠状分布。金项矿区盐构造分为两个阶段:古新世–始新世挤压–拗陷层内变形阶段,形成盐枕、隆升较低的盐背斜等整合型盐构造;渐新世的逆冲推覆–盐岩滑脱阶段,受强烈的挤压推覆作用而形成盐墙、盐株等盐穿刺型构造。盐构造不同阶段的变形演化对金属元素富集成矿起到关键作用,其流动变形而形成的盐构造圈闭促使了金属聚集成矿。     

地壳不同构造层次岩石变形机制及其构造岩类型

构造岩记录地壳构造变形演化重要信息,其成因、分类与命名一直没有统一认识。本文对构造岩变形机制、控制因素和构造岩分类进行系统总结。认为构造岩形成受物质成分、变形机制、应变速率、流体、温度、压力等因素控制,是物质成分与物理化学条件、变形机制等众多变量的函数。变形机制包括破裂作用、碎裂流动、晶质塑性、物质扩散、重结晶作用和超塑性流动,不同变形机制出现在不同地壳构造层次中,形成不同的显微组构。依据成因机制、物质组成和组构等标志对构造岩分类与命名进行重新修订,将构造岩划分为碎裂岩系列和变质构造岩系列,前者发育在地壳浅构造层次上,以破裂作用和碎裂流动变形机制为主;后者发育在中深部构造层次上,以晶质塑性、重结晶作用、物质扩散作用和超塑性流动作用为主。碎裂岩系列划分碎裂岩、角砾岩、微角砾岩、超碎裂岩、断层泥和假玄武玻璃;变质构造岩系列划分为构造片岩、糜棱岩和构造片麻岩。依据岩石流变性质、变形机制和构造岩分布,地壳构造层次划分为:脆性域,变形机制以碎裂作用和碎裂流动为主,发育碎裂岩系列;脆-韧性转换域,以晶质塑性、物质扩散和重结晶作用为主,并伴随有碎裂作用,形成糜棱岩、千糜岩和构造片岩;低温韧性域,以晶质塑性、物质扩散和重结晶作为主,发育糜棱岩与构造片岩;高温韧性域,以超塑性蠕变和重结晶作用为主,形成构造片麻岩。     

Exotic Olivine-Mica Rocks from the Udachnaya-East Pipe (Yakutia): Features of the Chemical Composition and Origin

The chemical composition of rock-forming minerals from unusual olivine-mica rocks from the Udachnaya-East kimberlite pipe (Yakutia) was studied. It is shown that all these rocks were formed as a result of the influence of deep metasomatic fluids. Two ilmenite-bearing rocks show the similarity to polymict breccia genetically representing analogs of protokimberlite melts, which did not reach the Earth’s surface. Two other rocks (one with K-bearing amphibole, another with clinopyroxene) are most likely rocks from the zones of high permeability, which were formed upon consolidation of the Siberian Craton and were subjected to the influence of aggressive fluids from the early portions of the protokimberlite melt.     

滨里海盆地东缘构造演化及油气成藏模式分析

滨里海盆地是中亚地区油气资源最为丰富的沉积盆地之一。本文以油气地质理论为指导,对盆地东缘的构造演化以及其油气成藏组合进行分析,认为乌拉尔造山运动对盆地东缘的构造演化造成了深刻影响。盆地东缘盐上层系的生烃条件较差,主要油气来源应为盐下层系。石炭系碳酸盐岩KT-I层和KT-II层是盆地东缘发育的良好储层。下二叠统盐层为区域性盖层,特别是对盐下油气藏起到了良好的区域封盖效果,盐相关构造圈闭类型发育。不整合面、断层和孔、洞、缝等组成复合的油气输导体系。盆地东缘的油气成藏模式主要为盐下层系的"自生自储型"和"下生上储型"以及盐上层系的"下生上储型"。     

库车坳陷克拉苏构造带盐上和盐下构造变形差异及其控制因素分析

克拉苏构造带位于库车坳陷与南天山盆山过渡带,特殊的受力环境使其构造变形机制具有特殊性。依据最新的地震和钻井资料,并结合前人研究成果,建立了克拉苏构造带新的地震解释方案,并据此分析该地区盐上、盐下层构造变形几何形态、演化过程、形成机制等方面的差异及其控制因素。结果表明:克拉苏构造带盐下层构造变形可分为两部分,包括由基底卷入的高角度正断层后期挤压形成的反转断裂系统,以及主断裂下盘发育的次生盖层滑脱逆冲叠瓦断裂系统。盐上层构造变形为褶皱相关断层,其演化经历了基底断裂向上传递形成传播褶皱、差异压实作用诱发底辟褶皱、以及褶皱核部在持续挤压作用下形成破冲断层等多个阶段。盐下层基底卷入断裂系统形成于侏罗纪盆山过渡带伸展环境,而叠瓦式盖层滑脱断裂系统和盐上层构造变形主要形成于中新世-第四纪的挤压构造环境。盆山过渡带特殊的构造部位及在不同地质时期应力场的转换控制了盐下层构造变形机制,而盐上层构造变形受到基底断裂复活、差异沉积负荷、膏盐岩底辟上涌、挤压应力增强以及北部山前地形高差等众多因素影响,且不同演化阶段主控因素有所差异。克拉苏构造带盐下、盐上层变形机制和毗邻区带相比有较大差异,这与其特殊的构造位置以及构造应力在盐下和盐上地层向前陆方向传递的方式和距离不同等因素有关。     

四川渠县三叠系膏盐的同生、成岩、后生及表生变化

本文论述了四川渠县三叠系的膏盐在沉积后的不同阶段所发生的各种变化,并提出根据膏盐的变化特征推测它们的原生沉积条件、卤水咸化程度及研究区的矿床保存条件。     

前陆褶皱冲断带厚皮缩短盐构造运动的物理模拟

尺度物理实验用干石英砂和聚合硅树脂为实验材料,模拟了前陆褶皱冲断带厚皮缩短盐构造,并与薄皮缩短盐构造及无盐层的褶皱冲断带构造模型进行了对比。实验表明,由于塑性盐层的存在,厚皮缩短盐构造呈3层式结构模式。盐上层主要形成敞开褶皱、箱状褶皱、前冲和背冲断层以及冲垒构造,盐下层形成逆冲断层及冲垒构造,断层通常都终止于盐层中。尽管盐层局部变薄或增厚,但不形成刺穿型盐构造。褶皱冲断带不具构造指向特征,其楔形库仑锥剖面呈平台与斜坡两段式形态。模型对比表明,厚皮缩短与薄皮缩短所产生的盐上层构造形态相似,不易区分;但二者的库仑锥剖面有所不同。厚皮前陆褶皱冲断盐构造与无盐层的褶皱冲断构造无论是其几何形态、还是库仑锥剖面都有极大的差别,极易区分：实验结果对解释前陆褶皱冲断构造和寻找盐下油气圈闭都有着重要的指导意义。     

云南兰坪-思茅盆地勐野井矿区钾石盐的特征及其沉积环境

本文运用X射线粉晶衍射(XRD)、透射电镜-能谱(TEM-EDS)和工业C T等方法,对云南江城勐野井钾盐矿床580m运输坑道地质剖面钾矿石的特征进行了研究。XRD和TEM-ESD结果给出,矿石中的盐类矿物主要是石盐、钾石盐、硬石膏和菱镁矿,钾石盐主要赋存在青灰色岩盐和灰绿色泥砾质岩盐中。CT结果表明,青灰色钾盐矿体中的石盐呈近似圆形和棱角分明的角砾,钾石盐沿石盐角砾的边缘呈条带状或不规则状分布,在条带状的内部可见钾石盐呈粒状或团块状分布,其中粒状钾石盐可能以八面体和立方体为主,而团块状钾石盐无特定晶形。钾石盐的这种分布特征表明,该盐类矿床在蒸发沉积过程中,早期沉积的石盐体呈遭受外力破坏,后期形成的钾石盐沿其裂隙沉积,表明钾石盐形成晚于石盐,且可能有多次沉积。     

Structural controls on carbonate-hosted Pb–Zn mineralization in the Dongmozhazhua deposit,central Tibet

Fault zones control the locations of many ore deposits, but the ore-forming processes in such fault zones are poorly understood. We have studied the deformation and ore textures associated with fault zones that controlled the lead–zinc mineralization of the Dongmozhazhua deposit, central Tibet, ∼100 km southwest of Yushu City. Geological mapping shows that the structural framework of the Dongmozhazhua area is defined by NW–SE-trending reverse faults and superposed folds that indicate at least two stages of deformation. The first stage is characterized by tight nearly E–W-striking folds that formed during the closure of the Jinshajiang Paleo-Tethyan Ocean in the Triassic. The second stage of deformation produced NW–SE-trending reverse faults and related structures of the Fenghuoshan–Nangqian fold-and-thrust belt associated with India–Asia collision in the late Eocene to Oligocene. Scanline surveys along the ore-controlling fault zones show an internal structure that comprises a damage zone, a breccia zone with clasts that have become rounded, and a breccia zone with lenticular clasts, and this complex architecture was formed during at least two compressional substages of deformation. The Pb–Zn mineralization in the Dongmozhazhua area occurs exclusively close to NW–SE-trending reverse fault zones. Microtextural observations reveal that mineralization occurred as veinlets and disseminated blebs in limestone clasts, and as continuous bands and cements in fractured rocks. Cataclastic sulfide grains also can be seen in the matrix of some fault zones. The types of mineralization differ with structural position. The fillings of the ore-bearing veinlets typify the products of hydraulic fracture and both types of mineralization took place concurrently with regional contraction. We consider, therefore, that the ore-bearing fluids in the Dongmozhazhua deposit were concentrated in fault zones during regional compression and that the ore minerals were precipitated during hydraulic fracturing of host rocks. Subsequent fault activity pulverized some pre-existing sulfide material into cataclastic grains in the matrix of a tectonic breccia that developed in the same faults.     

Depth-related variation of tourmaline in the breccia pipe of the San Jorge porphyry copper deposit,Mendoza, Argentina

The San Jorge porphyry copper deposit in Mendoza, Argentina in some parts contains breccia pipes that are strongly enriched with tourmaline of the dravite–schorl solid solution series with some quartz, muscovite, orthoclase, kaolinite, Cu sulfides and arsenopyrite. The overall composition of tourmaline is rather homogeneous with an intracrystalline variation of the Fe/Mg ratio reflected by its texture, its core-rim zonation of tourmaline and by the statistical variation of the Fe/Mg ratio. The depth-related intracrystalline changes are best interpreted as a hydrothermal collapse breccia which formed as a result of the reaction of primary hydrothermal B–Fe-enriched fluids with the country rocks enriched in Mg. The chemical composition attests to only small-scale interaction of tourmaline with silicate fragments within the tourmaline breccia itself. Tourmaline as one of the ultrastable heavy minerals in stream sediment offers a potential tool to discriminate between Cu-bearing and barren breccia pipes, using the Fe/Mg ratio of the boron silicate for distinction. Fertile breccias reveal a significantly better correlation between Fe and Mg than barren tourmaline breccias.     

Perspectives on the roles of melanges in subduction accretionary complexes: A review

Melanges play three principal, overlapping roles in the architecture of subduction accretionary complexes (SACs) during and after SAC formation. First, tectonic melanges serve as zones of concentrated deformation within and below the accreted rocks that are assembled during the subduction-accretion process. These melanges facilitate preservation of inter-melange, less deformed, accretionary units (AUs). Beneath the trench side of the SAC, the initial deformation zone along the decollement at the top of the down-going plate is marked by non-melange, tectonically dismembered formations or thinner units of scaly rock and breccia that separate accreted rocks above from the subducting rocks below. Olistostromal rocks may be incorporated into the decollement here. In the mid-arc to inner-arc areas of the SAC, exotic block-bearing mélanges develop in zones of tectonic fragmentation and mixing of accreting ocean plate stratigraphy, in mud diapirs, and along out-of-sequence faults, some of which facilitate uplift of high-pressure rocks and serpentinite-matrix mélanges. Second, after accretion, the sedimentary, tectonic, diapiric, and polygenetic mélange units serve as single block or sheet architectural AUs (or subunits within larger accreted AUs) of the SAC. Diapiric melanges and sedimentary olistostromal mélanges formed in and above SAC fault blocks, respectively, may become incorporated into the SAC during ongoing deformation and become architectural units, as well. Third, melanges serve as post-subduction stress guides that focus shear strain during continuing and post-accretion deformation of SACs, allowing ongoing modification of the SAC during progressive deformation of the orogen. Examples of each type of role reveal the importance of all three processes in the current architecture of outer orogenic belts.     

宁夏固原凹陷岩盐矿床后生改造成矿作用—来自矿物学的证据

为深入理解岩盐矿床复合成矿作用,研究宁夏固原凹陷岩盐矿成矿规律和成矿模式,在野外地质调查的基础上,通过镜下观察、扫描电镜分析、电子探针能谱分析、X射线粉晶衍射分析,结合岩石学和矿物学研究,对该矿床矿石结构构造特征和矿物特征进行对比研究,并对其岩盐矿成矿期次进行了划分。结果表明,固原凹陷岩盐矿矿石具有原生沉积和后生改造结构构造。矿石结构中自形细晶结构为原生沉积结构,自形粗晶、港湾和蠕虫交代结构为后生改造结构。矿石构造中纹层、条带、团块状构造为原生沉积构造,块状、角砾状和网脉状构造为后生改造构造。岩盐矿床矿物组合主要有石盐、钙芒硝、硬石膏、无水芒硝以及粘土矿物、钠长石、白云石,具有原生沉积和后生改造的矿物组合特征,盐类矿物均可见原生沉积型和后生改造型矿物。岩相学和矿物学研究证实,固原凹陷岩盐矿床是一个典型的原生沉积-后生改造型矿床。钙芒硝和硬石膏矿主要由早期沉积作用形成矿化体,经历了后期微弱的改造作用;而石盐矿主要由早期沉积作用形成矿体,在后期盆地构造变化中发生塑性流动、溶解-重结晶或构造变形而充填于围岩的裂隙或构造活动形成的有利空间中成矿,表明矿床经历了原生沉积成矿期和后生改造成矿期两个...     

塔里木盆地库车前陆褶皱带中段盐相关构造特征与油气聚集

塔里木盆地北部库车前陆褶皱带古新统一始新统发育盐岩层系，将库车前陆褶皱带构造变形和圈闭样式分为三层，即盐上构造、盐层(盐间)构造和盐下构造。盐上构造包括盐上背斜、盐上逆冲断层及断层相关褶皱、盐上背冲断块构造、强制褶皱、盐上逆冲断层遮挡构造和盐推覆构造等；盐层(盐间)构造主要包括盐枕构造、盐间断褶构造、盐焊接构造和外来盐席等；盐下构造主要有背冲断块构造、断层相关褶皱、叠瓦冲断带和双重构造等。库车前陆褶皱带盐构造的形成可能受挤压作用、重力滑动和重力扩展作用多重控制。笔者等讨论了盐相关构造油气成藏条件和模式，认为库车前陆褶皱带盐岩层变形与丰富的圈闭构造形成密切相关，烃源岩主要位于盐下，盐岩层作为优质盖层构成石油和天然气藏最优越的遮挡条件，断裂对盐下、盐间和盐上油气成藏都起重要控制作用，但盐下是最有利的油气聚集场所。     

柴西南翼山构造上新统狮子沟组混积岩地球化学特征及物源指示意义

柴西地区南翼山构造上新统混积岩中含有大量盐类矿物,其物源分析对盐矿物质来源研究有一定的参考价值。本文在野外观察和镜下鉴定的基础上,对南翼山构造上新统狮子沟组混积岩的地球化学特征进行了分析,并结合周缘造山带花岗岩的稀土元素数据,探讨了混积岩中陆源碎屑的物质来源。结果显示：南翼山构造狮子沟组混积岩中碎屑矿物、碳酸盐矿物和黏土矿物呈均匀混合的状态,元素含量与矿物组分密切相关,除Ca、Na、Sr元素外,其余元素含量普遍低于上地壳平均含量,其中CaO和Na2O受碳酸盐和石盐形成影响,不能用于判别构造背景,而Sc、Th、Zr、Hf等微量元素和稀土元素较完整地保留了源岩的地球化学信息,可用于源区构造背景的判别及物源示踪,同时稀土元素配分模式一致性较好,表明混积岩中陆源碎屑具有相同的物源特征。稀土元素配分模式、La Th Sc、Th Sc Zr/10、La/Th Hf图解以及Al2O3/TiO2比值共同指示南翼山混积岩的陆源碎屑组分来源于大陆岛弧背景下的长英质火成岩,通过与周缘造山带花岗岩稀土配分模式对比,推断晚志留世和晚二叠世花岗岩是混积岩中陆源碎屑和盐类矿物的主要源岩,南部的祁漫塔格是主要的物源区,且西部的阿尔金南段也有部分物源贡献。     

1 Geological Environment of Mineralization

Abstract The Puziwan gold deposit is a special linear cryptoexplosive breccia type deposit found in northeastern Shanxi, China, in recent years. The deposit is located in a secondary metallogenic belt of the most famous Au‐Ag polymetallic metallogenic belt along the north margin of the North China platform. The secondary metallogenic belt is a synmagmatic tension‐shear fault‐fracture belt of ENE linear trend. The Indosinian cryptoexplosive breccia body, quartz monzonitic porphyry (beschtauite breccia), quartz monzonite (243.7 Ma, K‐Ar), Yanshanian granite‐porphyry (105±6 Ma, Rb‐Sr) and orebodies mostly occur as dykes or veins and short lenses along the structural fracture belt. The orebodies are emplaced in the fractured cryptoexplosive breccia body in the tectonomagmatic belt and their attitude is consistent with that of the breccia body. The orebodies have two types: one is shallow‐seated thick and big ones, which are short‐lenticular in plan and wedge‐shaped in cross section, shallow buried, large in size and high‐grade; the other is lean orebodies, which occur as parallel veins at depths. The ores are mainly of Au‐Ag polymetallic sulphide‐rich breccia type. Pyrite (limonite) is the dominant metallic mineral, with subordinate chal‐copyrite, galena, sphalerite, tenantite, native gold, electrum, native silver and argentite. The gangue minerals consist mainly of quartz and plagioclase, with subordinate carbonate minerals, alunite chalcedony and kaolin. Kaolinization is the characteristic alteration type. Sulphide minerals contain abundant trace minerals such as Cu, Pb, Ag, Sb and Hg, while in the ores Ag, Cu, Pb, Zn, As and Sb are the best indicator element assemblage of Au. The δ³⁴S(%_o) values of the ores rane from ?3.2%_o to 5.3%_o, with average ?0.102%_o. The δO H₂O(%_o) and δ(%_o) values are in the ranges from ?3.1%_o to 7.73%_o and from ?64%_o to ?90%_o respectively. The Pb isotopic compositions of the rocks and ores in this region indicate that Pb comes from three tectonic sources—upper mantle, lower crust and orogenic belt. The inclusion homogenization temperature are in the ranges of 110 to 220°C and 230 to 310°C, which suggests that the deposit formed under meso‐epithermal conditions. The ore‐forming pressures range from 6 to 32 MPa and the depths are 230 to 1200 m. In view of the above, the Puziwan gold deposit is genetically ascribed to a high‐sulphur (alunite‐kaolin) meso‐epithermal gold deposit related to subvolcanic rocks. This gold deposit formed during the Indosinian stage (245.9±0.3 Ma) and then was influenced by a thermal event in the Yanshanian stage (142.9±0.5 Ma).     

陕西二台子铜金床钠长石碳酸（角砾）岩类特征及形成构造背景分析

从岩石学、矿物学、岩石化学、地球化学、稀土元素等方面研究了二台子铜金矿内长石炭酸（角砾）岩类地质地球化学特征。晚泥盆世－石炭纪,在区域幔羽构造作用下,深部热流体沿先存在构造通道上升进入镇安二台子三级热水沉积盆地之中,形成了石英重晶石炭酸角砾岩、碳酸角砾岩、复成分角砾岩、钠长岩、钠长石碳酸岩,受同性断裂及层位控制明显,并构成了金的矿源层及普遍金矿化。燕山期,具有幔源特征的深部含矿热流体在北东、北西向     

论中国盐溶角砾岩的特征和分类

中国的蒸发岩矿床非常丰富,与蒸发岩在成因上密切相关的盐溶角砾岩极其发育。本文简述了中国盐溶角砾岩的分布,总结了盐溶角砾岩的一般特征,划分出盐溶角砾岩的主要类型,探讨了盐溶角砾岩与盐泉的关系。     

内蒙古得尔布干成矿带铅锌银矿两期叠加成矿的矿物学证据--以乌尔根矿为例

内蒙古额尔古纳市乌尔根铅锌银矿是得尔布干成矿带上具有代表性的浅成中低温热液型铅锌银矿之一。显微镜下观察、电子探针分析结果等矿物学证据证明,该矿床存在2期成矿作用。其中早期火山热液形成的金属硫化物普遍受应力作用的改造,并广泛被晚期形成的矿物交代,典型矿物是不含乳滴状黄铜矿的闪锌矿,具有高含量Fe、Mn和低含量Cu的特征;晚期次火山(隐爆角砾岩)热液形成的金属硫化物占大多数,常交代早期形成的矿物并与其交生在一起,典型矿物是含固溶体乳滴黄铜矿的闪锌矿,并且具有中等含量Fe、Mn和高含量Cu的特征。在次火山热液期的晚阶段残余热液还形成了较为纯净的呈棕黄色-无色透明的纯净闪锌矿,具有高含量Zn,低含量Fe、Mn、Cu的特征。结合前人测定的研究区火山岩和矿石矿物定年结果以及火山岩主量元素组成数据,推测早期火山热液成矿与中基性塔木兰沟组火山岩关系密切,而晚期次火山(隐爆角砾岩)热液属于满克头鄂博组的(中)酸性岩浆热液的产物。隐爆角砾岩热液富含Cu元素且为成矿提供了主要物质来源,是研究区寻找除铅锌之外其他矿种的重要线索。     

Rise and fall of road salt contamination of water-supply springs

A storage pile of de-icing agent consisting principally of sodium chloride was placed in the recharge area of two springs, and remained there for 2 years. Water flow is through fractures in rocks with low matrix permeability, along a hydraulic gradient developed along fracture zones. Salt contamination in the springs was noticed about 1 year after the salt was placed. When the salt was removed 1 year later, chloride concentrations in the springs exceeded 500 mg/L. Monitoring for the following 5 years showed salt contamination rising for the first year, but receding to normal background after 5 years. Chloride to sodium ratios of the spring waters indicated that some sodium was initially sequestered, probably by ion exchange on clay minerals, in the early part of the monitoring period, and released during the latter part; thereby extending the period of contamination.Richard S. diPretoro: deceased