瞬变电磁法在地下金属物体探测中的应用   总被引：2，自引：0，他引：2  

李远强 《城市地质》2002,14(3):29-32

一种无损高分辨率电磁探测技术（TEM）－瞬变电磁法，它不同于探地雷达。它应用探测的电导率数据成图，可提供解释出地下埋藏的金属物体及相关信息，主要用于地下环境工程、市政工程、考古、军械遗弃场地的普查探测等领域，在设计、开挖、施工过程中，能够充分了解地下金属物体（金属管线等）的分布及地质情况，也能充分利用探测成果在盲区做集中、具体的工作。由高分辨率瞬变电磁技术所得的信息是非常重要的。  相似文献   

Development of schistosity by dissolution–crystallization in a Californian serpentinite gouge     

M. Andreani  A.-M. Boullier  J.-P. Gratier 《Journal of Structural Geology》2005,27(12):1476

To understand the behaviour and deformation mechanisms of serpentinites in the seismogenic zone we study the deformation macro- and microstructures of serpentinites along the Santa Ynez Fault in the San Andreas System. At the outcrop scale, deformation is localized in a gouge zone that shows three different structures: (1) micrometric undeformed fragments (clasts) of the previously serpentinized peridotite, (2) localized shear planes (Y and R) and (3) a penetrative schistosity (S). Observations under SEM and TEM reveal that the schistosity corresponds to serpentine fibres, parallel to each other, and whose orientation varies as they wrap around clasts. TEM micro-textures indicate that these long fibres result from continuous syntectonic growth rather than from reorientation of pre-existing fibres implying a slow transfer process that occurs at short distances. We propose a dissolution–diffusion–crystallization process for the formation of the schistosity that corresponds to a low strain-rate creeping process of deformation that can be effective in aseismic fault segments.  相似文献   

强场源TEM测量仪器和在大型矿山接替资源勘探中的应用研究          下载免费PDF全文

嵇艳鞠  林君  于生宝  朱凯光  王忠  王静 《地震地质》2005,27(1):115-122

针对矿山噪声强、要求勘探深度大的特点,应用强场源TEM测量仪器,采用双发射信号同步叠加增大发射磁矩,即通过增大发射电流和合理选择发射回线边长,提高瞬变信号晚延时的信噪比的方式提高有效勘探深度。在安徽铜陵凤凰山铜矿的实际勘探中,采用吉林大学研制的 2个ATEM-Ⅱ型发射机同时工作,将发射电流由 2. 4A增大到 38 .5A,晚延时瞬变信号的信噪比由 0 .275提高到2. 93,有效探测深度达到 650m以上,表明强场源TEM测量仪器在寻找大型矿山接替资源勘探方面具有较好的发展前景  相似文献   

几种氧化锰矿物的合成及其对重金属的吸附和氧化特性   总被引：7，自引：0，他引：7  

冯雄汉翟丽梅  谭文峰刘凡 贺纪正 《岩石矿物学杂志》2005,24(6):531-538

以改进或优化的方法合成土壤中常见的几种氧化锰矿物,对其形貌、结构、组成和表面性质进行表征,研究其对几种重金属的吸附和对Cr(Ⅲ)的氧化特性及与其结构和表面性质的关系。结果表明,合成的水钠锰矿、钙锰矿、锰钾矿和黑锰矿均为单相矿物,具有典型的形貌特征。水钠锰矿、钙锰矿和锰钾矿的PZC较低,分别为1.75、3.50和2.10,其表面可变负电荷量的大小顺序为水钠锰矿≥锰钾矿>钙锰矿;黑锰矿的PZC较高,表面可变负电荷量远低于其他3种矿物。供试矿物中,水钠锰矿对Pb2 、Cu2 、Co2 、Cd2 和Zn2 等重金属的吸附能力最强,黑锰矿的吸附能力最弱,除黑锰矿吸附更多的Cu2 外,供试氧化锰矿物对Pb2 的吸附量最大。氧化锰矿物对重金属的吸附受重金属的水解常数和矿物的表面负电荷的影响较大,它们均影响氧化锰矿物表面诱导水解作用及吸附离子形态。供试氧化锰矿物对Cr(Ⅲ)氧化能力和氧化过程中Mn2 释放量不同,受矿物结构、氧化度、表面性质以及结晶度等因素影响,氧化能力顺序为水钠锰矿>锰钾矿>钙锰矿>黑锰矿,最大氧化量分别为1330.0、422.6、59.7和36.6mmol/kg。  相似文献   

两类榴辉岩的石榴石变形特征差异——来自TEM研究的证据   总被引：9，自引：4，他引：9  

刘祥文金振民  金淑燕曲晶　徐薇 《岩石学报》2005,21(2):411-420

大陆碰撞造山带中超高压榴辉岩从变形程度上通常可以分为面理化榴辉岩和块状榴辉岩两类。本文利用透射电子显微镜对中国大陆科学钻探主孔岩心中面理化榴辉岩和块状榴辉岩的石榴石变形特征进行了比较研究。结果表明:(1)面理化榴辉岩中石榴石的位错密度比块状榴辉岩中石榴石的位错密度高大约3个数量级,位错密度达1.2×1010/cm2。并且有水分子团与高密度位错共存,表明主导石榴石发生强烈塑性变形的机制为水弱化的位错滑移。(2)块状榴辉岩中石榴石的位错密度低,没有观察到水分子团,虽然在局部发现有位错网,但总体上仍呈刚性。(3)两类榴辉岩的石榴石中占主导地位的位错滑移系都是1/2<111>{110},其次为<100>{010}。本文对变形石榴石晶体中水的赋存状态、水弱化机制及变形石榴石形态优选方位与晶格优选方位不协调问题进行了讨论:(1)水在石榴石晶体中有三种可能赋存状态:第一种是吸附于位错管道中的极化水分子;第二种是通过晶体表面以及位错管道扩散进入晶格的间隙水分子;第三种是以4OH-替代SiO44-形式的结构水。(2)石榴石水弱化机制有两种可能:一种是水弱化促进的位错滑移机制,在面理化榴辉岩石榴石的塑性变形中起主导作用;另一种是水弱化促进的扩散和颗粒边界滑移机制,在面理化榴辉岩石榴石的塑性变形中只起次要作用。(3)变形石榴石不产生明显的LPO是由其晶体结构本身特征所决定的,并不能排除其主导变形机制仍然是位错滑移的可能性。  相似文献   

TEM and XRD determination of crystallite size and lattice strain as a function of illite crystallinity in pelitic rocks   总被引：2，自引：0，他引：2  

W.-T. JIANG  D. R. PEACOR  P. ÁRKAI  M. TÓTH  & J. W. KIM 《Journal of Metamorphic Geology》1997,15(2):267-281

Average crystallite size and mean-square strain of illite in rock specimens and clay separates were measured independently in TEM images and by single-line Fourier (Voigt method) profile analysis of the c. 1 nm peak of XRD patterns for a prograde sequence of pelitic rocks (illite crystallinity indices=0.17–0.58°Δ2θ) from the Gaspé Peninsula, Quebec. The TEM-determined crystallite sizes in clay separates approximate those determined by Fourier profile analyses and those calculated from illite crystallinity indices by the Scherrer equation, with the exception of the diagenetic sample. The crystallite sizes and mean-square strains of illite in rock samples exhibit a trend similar to that determined by profile analyses, but the average crystallite sizes are up to five times larger than those measured for clay separates. TEM images show that all rock samples have a wide range of crystallite sizes, and the proportions of larger crystallites increase with metamorphic grade. The diagenetic illite is defect-rich, fine-grained (mean thickness by volume=c. 70 nm), 1M_d material. Anchizonal illite tends to occur as separate aggregates of small 1M_d and larger 2M₁ crystals (c. 200 nm), comprising arrays of subparallel coalescing packets. The epizone sample has thick (c. 400 nm), defect-free crystals of muscovite occurring in stacks of parallel layers, or subhedral crystals intergrown with large-angle boundaries. Cleaved crystals that are free of intracrystalline layer terminations are dominant in clay separates of all samples, having ranges of smaller sizes with volume-average thicknesses of c. 43, 43, and 81 nm (c. 14, 28, 67 nm by the Voigt method), respectively, for the three zones. The results suggest that illite crystallinity indices do not provide a direct measure of a single microstructural state of illite in rocks, although they yield consistent limits for average crystallite sizes for the anchizone (23 & 48 nm here). Therefore, they serve as a general parameter of the degree of recrystallization on a relative basis, in part because the contributions of all peak-broadening variables (mixed layering, size and strain) decrease regularly with prograde regional metamorphism of pelites. The microstructural changes caused by rock disaggregation are probably a function of those variables as well. The data collectively demonstrate a trend from metastable, defect-rich, small crystals towards a stable assemblage of larger, defect-free crystals, through dissolution of strained crystals and neocrystallization, consistent with the Ostwald step rule.  相似文献   

铀矿床中红色微晶石英的透射电镜研究     

闵茂中  张富生 《矿物学报》1995,15(4):383-386

本文在国内首次采用透射电子显微镜研究铀矿床中的含铀红色微晶石英，查明其中不可见铀主要呈超显微状沥青铀矿和铀石形式存在，从而改变了过去普遍认为该矿物集合体中的不可见分散铀是呈吸附状态存在的认识。  相似文献   

承德黑山绿泥石的透射电镜研究     

徐惠芳  胡梅生 《矿物学报》1990,10(3):204-207,T001

作者利用透射电镜技术,对河北承德黑山绿泥石化阳起石中的绿泥石小晶体进行了研究。除一般的±b/3堆垛无序的绿泥石外,还发现了局部区域中12层重复的绿泥石多型。导致此种结构的原因是绿泥石的结构单元层之间不仅发生±b/3的位移,同时还发生±a/3位移的规则堆垛。它应是阳起石蚀变过程中的中间产物,最终将转变为1层的绿泥石多型  相似文献   

天然变形微斜长石中几种面缺陷的透射电镜初步观察     

安琳吉 《矿物学报》1987,(2)

本文利用超高压透射电子显微镜对在相当于角闪岩相条件下天然变形的微斜长石进行了初步研究。研究发现,光学显微镜下看到的一组平行细纹不是出浴条纹,而是变形条带。另一种超显微构造——滑动小叶片见于变形条带邻区,它们和另一相矿物出港或沉淀形成的小叶片不同,是由矿物的变形造成的。变形条带、滑动小叶片以及比较常见的堆垛层错都相互平行,看来都是由分位错沿同一类型的滑移面运动形成的。  相似文献   

高温超导磁强计研制及在瞬变电磁法中的应用   总被引：1，自引：0，他引：1  

陈晓东  赵毅  邓晓红  吕国印  张杰  赵敬洗 《物探与化探》2006,30(3):229-232

高温超导磁强计具有直接测量磁场、低噪声、高灵敏度、动态范围大、频带宽低频响应好的特点,可以取代感应线圈作瞬变电磁法的接收传感器。在理论上,高温超导磁强计应用在瞬变电磁法中具有优势。以高温超导磁强计作收传感器和以感应线圈作收传感器,在瞬变电磁法上进行了大量的野外对比试验,结果表明:把高温超导磁强计应用于瞬变电磁法(TEM)勘探上,能够加大勘探深度。  相似文献