常规次生晕法在广西资源县云头界钨钼矿找矿中的成果及意义   总被引：3，自引：0，他引：3  

伍静  梁华英  娄峰  张献河  胡光黔 《矿床地质》2010,29(2):301-307

广西资源县云头界钨矿异常区多被表土覆盖,局部出露钨矿化。据钨重砂矿物化学性质较稳定,风化剥蚀后迁移距离较近,而异常区表土覆盖不厚的特点,采用次生晕化探方法对云头界钨矿异常区1.4km2开展化探扫面找矿。根据8条化探剖面线共575个样品分析结果,圈出了6个钨异常区,在其中4个钨异常区施工槽探工程,都发现对应的石英脉型钨矿体。这揭示了该区矿体与次生晕异常的分布具有非常一致的对应关系。次生晕化探异常表明,该矿主矿脉沿走向长度超过1km,矿床规模可望达到中型。常规次生晕法在云头界钨矿异常区找矿效果明显,这对华南风化土层覆盖区钨矿找矿工作有重要的启示。  相似文献   

Oxidative pre-treatment in thiosulphate leaching of sulphide gold ores     

D. Feng  J.S.J. van Deventer 《International Journal of Mineral Processing》2010,94(1-2):28-34

A diagnostic leaching showed that partial oxidation of the sulphide minerals in a gold ore was beneficial for thiosulphate leaching of gold. A pre-treatment process with oxidative ammoniacal solution enhanced the thiosulphate leaching of the sulphide ore, while the thiosulphate consumption was substantially reduced. The sulphide minerals partially decomposed in the pre-treatment process, exposing gold to the leach solution. Oxygen input by air bubbling and a longer contact time enhanced the oxidative ammonia pre-treatment process and hence accelerated subsequent thiosulphate leaching of the sulphide ore. Gold extraction in 0.8 M ammonia and 0.1 M thiosulphate solution after 24 h increased from 69% without pre-treatment to 81%, 84%, 90% and 94% respectively after 1, 3, 7 and 22 h pre-treatment. The consumption of sodium thiosulphate was 2.37 kg/t after 24 h leaching without pre-treatment, but was negligible after over 1 h oxidative ammonia pre-treatment. A counter-current leaching process was conducted in the leaching of the sulphide ore. The fresh leachant still gave higher leaching rates in contact with the pre-leached ore, while the pre-used leachant had significantly lower leaching kinetics and overall gold extraction in contact with the fresh ore. This 2-step counter-current leaching process proved that the leachant, other than the passivation, was the determinant factor causing the gold leaching rates to decrease after a certain time of leaching. The findings enable the thiosulphate leaching of high sulphide containing gold ores to be more efficient at lower thiosulphate consumption following the oxidative ammoniacal pre-treatment.  相似文献   

兰坪盆地演化与成矿特征   总被引：2，自引：0，他引：2  

张峰 《地质与勘探》2010,46(1):85-92

兰坪盆地的演化受控于盆地所处的构造背景,经历了中三叠世至早侏罗世的陆内裂谷盆地、中-晚侏罗世的拗陷盆地、白垩纪的前陆盆地、古新世-中新世的走滑盆地。盆内成矿与盆地性质密切相关,陆内裂谷盆地阶段是重要的成矿期,具热水沉积矿床特征;拗陷盆地阶段多形成铜多金属矿床;前陆盆地阶段为喜山期的成矿作了物质准备;走滑盆地阶段,由于推覆构造活动强烈,深部流体和浅部红层中的盆地流体的混合,提供了大量的矿物质,并就位于构造圈闭中,形成如金顶铅锌矿等大型矿床。  相似文献   

鄂尔多斯盆地天环坳陷迁移演化与坳陷西翼油气成藏   总被引：2，自引：0，他引：2  

李相博  刘化清  陈启林  郭彦如  完颜容  魏立花  冯明  廖建波  马玉虎 《地质科学》2010,45(2):490-499

鄂尔多斯盆地是我国陆上最重要的含油气盆地之一,本文以鄂尔多斯盆地西缘为研究对象,以地震反射资料为基础,主要采用地震剖面"层拉平"与"平衡剖面恢复"等技术手段,对天环坳陷形成与迁移演化历史进行了动态分析。研究结果表明:1)天环坳陷最早形成于晚侏罗世,后期由于受燕山晚期及喜马拉雅山期构造运动影响,坳陷核部逐渐向东迁移至现今位置,前后累计迁移距离约30 km;2)当坳陷核部向东迁移至有效烃源岩范围附近时,原先已形成的油气藏发生重新调整,油气向坳陷西翼高部位运移、聚集,从而形成了次生构造油气藏。  相似文献   

安徽峙门口铜—铁—金—硫矿床地球化学特征     

李红阳  王金芳  冯景志  侯增谦  杨竹森  蒙义峰  王聪颖  陈文韬 《地质科学》2010,45(3):863-872

峙门口铜—铁—金—硫矿床发育上部层状矿体和下部脉状矿体。上部层状矿石重晶石的δ~(34)S值为+14.10‰～+18.90‰。上部层状矿石黄铁矿和方铅矿的δ~(34)S值为+3.50‰～+5.84‰,下部脉状矿石黄铁矿的δ~(34)S值为+4.80‰～+6.80‰。下部脉状矿石中脉石英的δ~(18)O值为+14.3‰～+1 8.5‰,δ~(30)Si值为-0.3%0～-0.2‰。下部脉状矿石黄铁矿Re/Os比值为78.342～175.540,上(顶)部层状矿石中黄铁矿Re/Os比值为62.298～169.545。从下部脉状矿石到上部层状矿石,δ~(34)S值、Re/Os比值和流体包裹体温度249 ℃→97 ℃逐渐降低,~(206)Pb/~(204)Pb、~(207)Pb/~(204)Pb、~(208)Pb/~(204)Pb平均值和Os_总、Re、~(187)Re等含量逐渐增高。矿石黄铁矿Re-Os同位素等时线年龄303±33 Ma。地质地球化学特征反映峙门口铜—铁—金—硫矿床为海底热水喷流沉积成因。  相似文献   

青藏高原西北缘盆山过渡带陡坡地貌的形成时代与成因   总被引：1，自引：0，他引：1  

黎敦朋  赵越  刘健  万景林  郑德文  潘燕兵  何哲峰 《地质科学》2010,45(4):930-943

平均海拔大于4500 m的青藏高原,是通过高原边缘的陡坡地貌与海拔低于1500 m的周缘盆地或平原相连接的,这些围绕高原的陡坡地貌是何时、如何形成的呢？本文通过对西昆仑山中段北缘主逆冲断层上盘陡坡地貌区9件磷灰石样品的裂变径迹年龄与长度分析表明：在海拔3900～4635 m的陡坡地貌中的裂变径迹样品年龄为6.2±1.4 Ma～0.9±0.3 Ma,呈现“上新下老”的反序分布特征; 而通过热历史模拟显示约5 Ma,约3～2 Ma,约2～1 Ma 和约1 Ma该地区出现多阶段的隆升与剥露。结合前人研究成果和野外地质的观察认为,现今青藏高原西北缘陡坡地貌的形成是中新世晚期以来高原边界叠瓦状断裂系经历了约8 Ma、约5 Ma、约3～2 Ma、约2～1 Ma和约1 Ma多阶段后展式逆冲运动的结果,这为青藏高原周缘陡坡地貌的形成和青藏高原的隆升时代与型式提供了关键的热年代学约束。  相似文献   

Some Fundamental Issues in Dynamic Compression and Tension Tests of Rocks Using Split Hopkinson Pressure Bar   总被引：12，自引：7，他引：5  

Feng Dai  Sheng Huang  Kaiwen Xia  Zhuoying Tan 《Rock Mechanics and Rock Engineering》2010,43(6):657-666

Accurate characterizations of rock strengths under higher loading rates are crucial in many rock engineering applications. The split Hopkinson pressure bar (SHPB) system has been used to quantify the dynamic compressive strength of rocks using the short cylindrical specimen and the dynamic tensile strength of rocks using the Brazilian disc (BD) specimen. However, SHPB is a standard tool that is suitable for metal testing; there are some fundamental issues that need to be carefully visited in applying SHPB to rock dynamic tests. This paper addresses several such critical issues, including the choice of slenderness ratio of the compressive specimen, the effect of friction between the sample and bars on the measured results of compressive strength, the necessity of dynamic force balance on the dynamic BD test, and the validity of using the standard BD equation in the data reduction. We show that with proper experimental designs that address these issues, the dynamic compressive strength and dynamic tensile strength of rocks measured using SHPB are valid and reliable.  相似文献   

Application of the stable-isotope system to the study of sources and fate of Hg in the environment: A review     

Runsheng Yin  Xinbin Feng  Wenfang Shi 《Applied Geochemistry》2010

With the improvement of analytical methods and the development of multiple-collector inductively coupled plasma-mass spectrometry (MC-ICP/MS), research on non-traditional stable isotope (Cu, Zn, Fe, Se, Mo, Cr, Hg) in geochemistry has made tremendous progress in the past decade. Recent studies have demonstrated that both organic and inorganic reactions may cause Hg isotope fractionation, and variations of Hg isotopic composition in the environment have been successfully employed to explain Hg pollution history, Hg sources and tracking Hg pathways in nature. Furthermore, Hg isotopic fractionation studies can be a powerful tool in the calibration of global Hg cycling models. Stable isotope geochemistry of Hg is therefore becoming a new frontier subject in earth sciences. Based on summarizing previous research, this paper outlines the main advances in the study of Hg stable isotopes with particular emphasis placed on a brief explanation of Hg isotope analytical techniques, possible Hg isotope fractionation mechanisms observed in both natural and experimental processes, Hg isotope composition variations in different environmental matrices, and the application prospects of the Hg stable isotopes in environmental geosciences.  相似文献   

基于熵权的集对分析法在水资源可持续利用评价中的应用——以塔里木河三源流地区为例   总被引：2，自引：0，他引：2  

黎枫  陈亚宁  李卫红  孟丽红 《冰川冻土》2010,32(4)

以塔里木河三源流地区为研究对象,结合研究区2004-2007年统计年鉴资料,从社会经济、水资源和生态环境三方面构建水资源可持续利用评价指标体系,采用集对分析和熵权法,对研究区水资源可持续利用进行评价.结果表明:塔里木河三源流地区水资源开发利用已基本达到饱和,水资源可持续利用呈现弱不可持续状态,具体表现为和田地区(Ⅲ)阿克苏地区(Ⅲ)喀什地区(Ⅲ).基于评价结果提出了一些促进三源流地区水资源可持续利用的措施.  相似文献   

塔里木河流域适应气候变化和人类活动的应对措施   总被引：3，自引：1，他引：2  

刘湘  段建军  陆峰  苟树生  沈永平  高前兆  王顺德 《冰川冻土》2010,32(4)

自2001年开始实施塔里木河流域近期综合治理工程,提出了以强化流域水资源统一管理和调度为核心,以源流区节水改造和干流河道治理为重点进行综合治理,积极稳妥地进行经济结构调整,实施退耕封育保护,有效保护好现有天然林草植被.通过向塔里木河下游生态输水,干涸近30a的台特玛湖于2001年11月16日开始有水,使塔里木河下游绿色走廊得到初步复苏等,流域生态环境得到极大的恢复.然而,自2007年以来,塔里木河向下游输水已大为减少,仅能输水到中游,特别是2009年水文干旱,塔里木河干流断流达1 100km多,使下游绿色走廊再度陷入生态危机.为此,需要重新审视塔里木河流域的综合治理,从加强源流治理开始,来巩固干流治理成果.认真总结10a来治理经验与教训,针对人类活动和气候变化对源流与干流造成的影响程度,积极采取应对措施.  相似文献