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岩浆岩成矿性判别系列方法 总被引:1,自引:0,他引:1
针对我国现行岩浆岩成矿性判别方法存在的问题,笔者统计了国内主要矿产地和国外部分矿产地的成矿和非成矿岩体的有关资料,发现单一的岩浆岩化学成分及用化学成分计算的各种参数,不具成矿性判别功能的作用。只有用成矿元素丰度及其有关的岩石化学成分组合起来计算的比值、参数等,才是区分岩浆岩成矿性的有效标志。本文提出的岩浆岩成矿性判别系列方法,简便有效,不受时空制约,与国内同类方法相比,更具广泛的适用性。 相似文献
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豫西银金多金属矿床成矿系列及其共生组合规律 总被引:3,自引:1,他引:3
豫西地区金银铅多金属矿床成矿系列,包括石英脉型,构造蚀变岩型,爆破角砾岩型,层间破碎岩型,矽卡岩型和斑岩型矿床,成矿系列各类型金属铅多金属矿床的同源,同期,不同阶段,不同成矿空间的矿床产出组合,并从成矿时间,空间,产出型式和成因上论述了其成矿的共生性,分带性,过渡性,互补性,连续性和重叠性等共生组合规律,举出实例阐明了研究金银铅多金属矿床成矿系列的找矿意义。 相似文献
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成矿系列的结构模型研究 总被引:1,自引:0,他引:1
由单个矿床研究到成矿系列和成矿系统研究,是成矿学研究的重要进展。在成矿系列理论的探索中,成矿系列的结构尤需关注,因此将成矿系列的内部结构概括为物质的、空间的和时间的三类。其中物质结构包括各矿种、矿床类型间的同源性、多样性、继承性和互补性;空间结构包括各矿种、矿床类型间的共生性、分带性、过渡性、集约性和重叠性;而成矿系列的时间结构含各矿种、矿床类型间的时限性、阶段性、渐进性和突发性,并举例论述了这些结构性质的形成条件,对深入认识成矿规律和指导找矿预测均有参考意义。 相似文献
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中条山—塔儿山成矿带Cu—Fe—Au矿床成矿系列及成矿模式 总被引:2,自引:0,他引:2
中条山-塔儿成矿带属滨西太平洋成矿域华北断块金,银,铜,铅,锌,锰,铝土矿、金刚石成矿区的3级成矿带,其中包括2个成矿系列,7个成矿亚系列和11个矿床式。2个成矿系列具有成矿世代的“双层性”,成矿物质来源的二元性,成矿作用的三阶段和矿化带展布与地质构造单元的趋近性等一系列特征。 相似文献
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张学书 《有色金属矿产与勘查》1997,6(1):37-41
从裂谷成矿背景着手,系统分析了禄武地区的成矿背景,规律及找矿,认为本区进一步的找矿工作应侧重行裂谷斯后偏酸性岩浆活动的成矿,并提出了可能存在的酸性岩浆成矿的理想模式。 相似文献
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对岩浆岩成矿性判别指标的探讨 总被引:1,自引:0,他引:1
岩体是否成矿的根本原因是所含成矿元素丰度的高低。岩体形成什么矿产则受不同岩类所含成矿元素种类的制约。显然,岩石类型仅起储存成矿元素的载体作用。据此,笔者以成矿元素丰度为依据,首创了岩体成矿指数等11种成矿性判别的最佳定性指标。 相似文献
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考虑核电厂地基-基础的动力相互作用,应用显式动力有限差分法分析了地震作用下极软岩、较软岩、坚硬岩上核电厂建筑结构基础的地震响应特征,比较了岩石坚硬程度对基础加速度反应谱的影响。研究表明:随着岩石坚硬程度的提高,核电厂建筑物结构基础的地震响应有增加的趋势;在周期轴上,基础处的加速度反应谱曲线会随着岩石坚硬程度的提高逐渐向短周期(高频段)方向移动。在高频段,建造于较坚硬岩石上基础结构的加速度反应谱值偏大;在中等频段,建造于较软岩石上基础结构的加速度反应谱值偏大;在低频段,岩石坚硬程度对加速度反应谱的影响不显著。 相似文献
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M. D. Sharma 《Journal of Earth System Science》2004,113(2):247-257
Three dimensional scattering of near-field is studied for dilatation and rotation in the time domain. The perturbation method
is applied to solve the equation of motion for the first order scattering from a weak inhomogeneity in an otherwise homogeneous
medium. The inhomogeneity is assumed close enough to the point source so that the near-field intermediate wave is dominating
over the far-field sphericalP andS pulses. The integral expressions are derived to relate dilatation and rotation of scattering to the radial fluctuations of
velocities and density in the inhomogeneity. These integrals are solved to calculate the strains of scattering from (a part
of) an inhomogeneous spherical shell of arbitrary curvature. Variable curvature may allow the shape of inhomogeneity volume
element to change uniformly from spherical to rectangular. Rotation of scattering from a spherical shell is independent ofP wave velocity inhomogeneity. Dilatation of scattering does not involveS wave velocity inhomogeneity but its gradient. The back scattering results are obtained as a special case. Strains are computed
numerically, for hypothetical models to study the effects of various parameters viz., velocity inhomogeneity, distance of
source from inhomogeneity and from receiver, and thickness of inhomogeneity. The curvature of the spherical shell is varied
to study the effects of the shape of inhomogeneous volume element on scattering. 相似文献
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地震次生地质灾害风险评估集对态势分析 总被引:2,自引:0,他引:2
5.12四川汶川8级强震引发了大量次生地质灾害,加剧了灾情并严重影响抗震救灾。地震次生地质灾害受多重因素制约,其孕育与致灾过程具有不确定性。利用集对分析原理与方法,对地震次生地质灾害进行同异反态势分析,拟定了风险评估的集对分析同一度、差异度、对立度等指标体系的构建原则与赋值标准,对承灾体系统的不确定性及其作用作了刻画与分析,建立了不同风险分区代表性的集对分析联系度表达式,为地震灾害研究提供了可资借鉴的新思路和技术方法。 相似文献
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Ivan V. BRAGIN Georgy A. CHELNOKOV Oleg V. CHUDAEV Natalia A. KHARITONOVA Sergey V. VYSOTSKIY 《《地质学报》英文版》2016,90(1):276-284
Studied waters belong to warm(T=30-50℃),alkaline(pH=8.9-9.3),low mineralized(TDS235 mg/1)Na-HCO_3 or Na-SO_4-HCO_3 thermal waters with high content of SiO_2(up to 81 mg/l)and F(up to 3.9 mg/1),occur on modern volcano-tectonic rejuvenated areas of Eastern Sikhote-Alin orogenic belt.Low~3He concentration as well as N_2/O_2 and N_2/Ar ratios exclude influence of deep mantle fluid.New rare earth element data constrain our understandmg of water-rock interaction occurring in the water source region.Meteoric origin of waters is proved by stable isotope values varying from-71‰to-136.1‰and from-10.8‰to-18.8‰forδ~2U andδ~(18)O respectively.REE patterns reflect high pH,resultfing from water-rock interaction and oxidative conditions.Calculations of deep aquifer temperature using Na-K and quartz geothermometers show 116.8-131.1°C and 82.2-125.8℃respectively.Presence of deep faults both with abnormal thermal gradient(~45-50 K/km)define unique geochemical shape of thermal waters of Sikhote-Alin,area,where no present volcanic activity is registered. 相似文献
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下扬子区三叠纪古地理演化 总被引:2,自引:2,他引:0
下扬子区在三叠纪期间接受了早-中三叠世海相碳酸盐沉积、中-晚三叠世海陆交互相和陆相湖沼沉积.沉积相带的空间分布和古地理格局的变迁明显地受到区域构造的控制.区内盆地发育与演化是在华南板块与扬子板块、扬子板块与华北板块相互作用的背景下进行的.早-中三叠世末期的印支运动是下扬子区构造-古地理格局改变的决定性因素,使下扬子海盆闭合,沉积类型由海相沉积变为陆相沉积.下扬子区三叠纪古地理的演化特征也为板块碰撞提供了沉积证据. 相似文献
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Isothermal thermogravimetric experiments have been carried out to determine the reaction kinetics of the dehydration processes
in fuller's earth, a natural Ca-montmorillonite. Dehydration in swelling clays is a complex reaction, and analysis of the
thermogravimetric data using empirical rate equations and time-transformation analysis reveals that the nature of the rate
controlling mechanism is dependent upon both the temperature regime of the sample as well as the extent of reaction. For fuller's
earth, we find that the dehydration kinetics are dominated by a nucleation and growth mechanism at low temperatures and fractions
transformed (stage I), but above 90 °C the last stages of the reaction are diffusion controlled (stage II). The activation
energy for dehydration during stage I is around 35 kJ · mol−1, whereas the removal of water during stage II requires an activation energy of around 50 kJ · mol−1. These two stages of dehydration are associated with primary collapse of the interlayer (stage I) and movement of water that
is hydrated to cations within the interlayer (stage II).
Received: 28 August 1998 / Revised, accepted: 27 January 1999 相似文献