共查询到20条相似文献,搜索用时 46 毫秒
1.
2.
四川省宁南县跑马铅锌矿地质特征及找矿前景分析 总被引:1,自引:0,他引:1
宁南跑马铅锌矿集中产于下寒武统麦地坪段潮坪一泻湖相的粘土一藻白云岩一硅质白云岩组合中,受平行不整合面和褶皱的层间破碎带、裂隙密集带、断裂等控制,为典型的沉积改造型矿床;矿床经历了沉积和改造两个成矿期,即在麦地坪段沉积过程中铅、锌初始富集形成矿源层,经后期热液叠加改造富集成矿,矿区具备大型铅锌矿床的成矿条件,找矿前景良好。 相似文献
3.
四川省峨边县华竹沟磷矿位于九坝背斜的南东翼,赋存于下寒武统麦地坪组(?1m)的中下部,层状延伸,其产状与含磷层一致,层位稳定。通过对矿区地层、构造、矿床地质特征的系统分析,研究古构造、古地理环境,认为磷块岩矿床受古构造和古地理环境的制约,经上升洋流、生物化学、潮汐机械沉积等成矿作用的反复叠加,形成本工业磷矿床。矿床成因属浅海生物化学盆内成屑再沉积成因的磷块岩矿床。 相似文献
4.
20世纪90年代以来,四川地矿局207地质队及地方采矿业在扬子地台西缘大渡河谷沿岸,相继发现了黑区—雪区、红花、白熊沟、核桃坪、养善坪—中溪坪—宝水溪—双凤沟等层状铅锌矿床及矿点。其中,黑区—雪区矿床的矿体地表露头长达6000m,估算的铅锌资源量达370万吨,达到超大型矿床的规模。不同的矿床、矿点的分布构成了长度大于50km的铅锌矿化带,预测铅锌资源量有望达1000万吨以上。各矿床、矿点产于上震旦统—下寒武统灯影组顶部麦地坪段含磷硅质白云岩的相同层位,矿化与硅质岩及角砾状白云岩层关系密切。矿床中发育层状、纹层状、条带状、同沉积角砾状、层间揉皱等构造,沉积特征明显。矿床的地质、地球化学特征显著区别于区域上以往发现的产于地台盖层碳酸盐岩中具有明显后生成因特点的密西西比河谷型(MVT型)铅锌矿床,也有别于产于中元古界褶皱基底中的火山沉积块状硫化物型(VMS型)铅锌矿床。笔者的研究表明,与铅锌矿密切共生的硅质岩为典型的海底热水沉积产物,铅锌矿床属于海底喷流—沉积成因(SEDEX型);成矿作用受晚震旦世—早寒武世北东东向延伸的汉源—峨眉凹陷及同生断裂带的控制。该类层状铅锌矿床可能是扬子地台西缘铅锌矿聚区中最具找矿潜力的矿床类型。 相似文献
5.
6.
7.
四川雷波地区磷矿属于中国昆阳式海相沉积型磷矿,赋存于下寒武统梅树村阶麦地坪组地层中。通过野外实测剖面,重点研究其岩石学和沉积相特征,在矿集区建立了潮坪沉积体系,判断麦地坪组以潮下带沉积为主,潮间带和潮上带沉积不发育,总体表现为海侵-海退-海侵的垂向沉积组合。沉积相在矿集区呈环带状分布,磷矿层厚度与地层厚度大体呈正相关关系。磷矿床的岩相古地理类型直接影响了磷质颗粒的物理富集过程,其中潮下高能带为磷矿沉积的最有利相带,是今后勘探开发的重点区域。 相似文献
8.
9.
辣菜水锌矿床产于海西-印支期盆地边缘,矿体严格受石炭系下统石磴子组下亚段白云岩控制,呈层-似层状,具层控型特征。矿床成矿具有多期性,早期沉积为矿胚层,受断裂构造热动力改造成矿体,后期岩浆热液叠加,矿体进一步富集,形成富闪锌矿体。通过成矿环境及矿床特征研究分析,认为该矿床成因属于沉积-改造-叠加的复控型矿床。 相似文献
10.
11.
S. Viswanathan K. Surya Prakash Rao B. Mahabaleswar 《Journal of the Geological Society of India》2013,82(6):621-627
Komatiites are mantle-derived ultramafic volcanic rocks. Komatiites have been discovered in several States of India, notably in Karnataka. Studies on the distribution of trace-elements in the komatiites of India are very few. This paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence (WDXRF) spectrometric technique for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites, and discusses the accuracy, precision, limits of detection, x-ray spectral-line interferences, inter-element effects, speed, advantages, and limitations of the technique. The accuracy of the technique is excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Zr, Nb, Ba, Pb, and Th and very good (within 4%) for Y. The precision is also excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th. The limits of detection are: 1 ppm for Sc and V; 2 ppm for Cr, Co, and Ni; 3 ppm for Cu, Zn, Rb, and Sr; 4 ppm for Y and Zr; 6 ppm for Nb; 10 ppm for Ba; 13 ppm for Pb; and 14 ppm for Th. The time taken for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in a batch of 24 samples of komatiites, for a replication of four analyses per sample, by one operator, using a manual WDXRF spectrometer, is only 60 hours. 相似文献
12.
奥地利安东帕有限公司 《岩矿测试》2009,28(3):306-306
最新的流行病学研究表明,空气中较高浓度的悬浮细颗粒可能对人类的健康有不利的影响。根据该项研究显示,由于心脏病、慢性呼吸问题和肺功能指标恶化而导致死亡率的升高与细尘粒子有关。这些研究结果已经促使欧盟于1999年4月出台了限制空气中二氧化硫、二氧化氮、氧化氮、铅和颗粒物含量的法案(1999/30/EC),对各项指标包括对可吸入PM10颗粒的浓度提出了新的限制性指标。PM10颗粒是指可以通过预分级器分离采集的气体动力学直径小于10μm的细颗粒。目前研究的兴趣重点逐步偏向PM2.5这些更细微颗粒物,PM2.5这种颗粒物对健康有明显的不利影响。在欧盟指令2008/50/EC中,对PM10和PM2.5都提 相似文献
13.
E. M. Prasolov S. A. Sergeev B. V. Belyatsky E. S. Bogomolov K. A. Gruzdov I. N. Kapitonov R. Sh. Krymsky V. O. Khalenev 《Geochemistry International》2018,56(1):46-64
This paper reports the first results of a study of 11 isotope systems (3He/4He, 40Ar/36Ar, 34S/32S, 65Cu/63Cu, 62Ni/60Ni, 87Sr/86Sr, 143Nd/144Nd, 206–208Pb/204Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others. 相似文献
14.
15.
16.
Mining induced subsidence can significantly affect mining costs where major surface facilities and natural environment need to be protected. Overburden grout injection is a technology used to control coal mine subsidence by injecting the mine waste material extracted from the coal back into the inter-burden rock during longwall mining. The flowing slurry is here categorised as a nonlinear viscous cohesive (Bingham plastic) fluid. During longwall mining the grout slurry is pumped into the separated beds of the rock mass through a central vertical borehole, which is drilled deep into the inter-burden rock strata above the coal seam. However, a blockage can occur in the injection system when the slurry velocity falls below a certain critical threshold velocity, indicating a material phase change from cohesive-viscous to cohesive-frictional. In situ field injection tests through boreholes have been simulated at a smaller scale at the CSIRO laboratory in Brisbane by pumping the slurry through a radial disk (gap = 4 mm) from its centre. Laboratory experiments indicate a general, nonlinear, cohesive, viscous, frictional model for shear behaviour of the slurry, in which the material shear parameters are functions of the disk radial distance. Complete dimensional and dimensionless analytical solutions have been developed based on an approach related to Bingham–Herschel–Bulkley fluid mechanics. The derived formulae include relations for minimum pump pressure, local pressure and pressure gradient, wall shear stress, volume rate, velocity and velocity gradient. The theoretical results match the experimental measurements. The experiments covered slurries with maximum particle sizes of 0.5 to 2 mm with about 50% being larger than 100 µm. The viscosities at the various solids concentrations were measured with a standard torsion viscometer. This study differs from the previous research in several distinct aspects, namely, consideration of the variable shear parameters rather than fixed values, inclusion of total nonlinear behaviour, and implementation of a friction function to mimic behaviour of the deposited and consolidating stiff slurry, which can cause a significant pressure rise as a result of the increased shear resistance. 相似文献
17.
18.
Between 1985 and 1991, two new mountain protected areas (MTNPA) covering more than 35,000 km2 and based on participatory management models — the Makalu-Barun National Park and Conservation Area, Nepal, and Qomolangma Nature Preserve, Tibet Autonomous Region — were successfully established through the collaborative efforts of Woodlands Mountain Institute and conservationists in China and Nepal. Characteristics common to both projects include the importance of establishing (1) effective rationales, (2) local support constituencies, (3) a senior advisory group, (4) a task force, (5) linkages between conservation and development, and (6) fund raising mechanisms. The lessons derived from the experiences of Woodlands Mountain Institute are of significant value to others in preserving MTNPA. Increased collaboration and communication between all interested in conservation, however, will remain a critical component for expanding mountain protected area coverage to throughout the world. 相似文献
19.
《Applied Geochemistry》2001,16(2):137-159
Five hundred and ninety-eight samples of terrestrial moss (Hylocomium splendens and Pleurozium schreberi) collected from a 188,000 km2 area of the central Barents region (NE Norway, N Finland, NW Russia) were analysed by ICP-AES and ICP-MS. Analytical results for Al, B, Ba, Ca, K, La, Mg, Mn, Na, P, Rb, Si, Sr, Th, U and Y concentrations are reported here. Graphical methods of data analysis, such as geochemical maps, cumulative frequency diagrams, boxplots and scatterplots, are used to interpret the origin of the patterns for these elements. None of the elements reported here are emitted in significant amounts from the smelting industry on the Kola Peninsula. Despite the conventional view that moss chemistry reflects atmospheric element input, the nature of the underlying mineral substrate (regolith or bedrock) is found to have a considerable influence on moss composition for several elements. This influence of the chemistry of the mineral substrate can take place in a variety of ways. (1) It can be completely natural, reflecting the ability of higher plants to take up elements from deep soil horizons and shed them with litterfall onto the surface. (2) It can result from naturally increased soil dust input where vegetation is scarce due to harsh climatic conditions for instance. Alternatively, substrate influence can be enhanced by human activity, such as open-cast mining, creation of ‘technogenic deserts’, or handling, transport and storage of ore and ore products, all of which magnify the natural elemental flux from bedrock to ground vegetation. Seaspray is another natural process affecting moss composition in the area (Mg, Na), and this is most visible in the Norwegian part of the study area. Presence or absence of some plant species, e.g., lichens, seems to influence moss chemistry. This is shown by the low concentrations of B or K in moss on the Finnish and Norwegian side of the (fenced) border with Russia, contrasting with high concentrations on the other side (intensive reindeer husbandry west of the border has selectively depleted the lichen population). 相似文献
20.
Marta L. PATINO-DOUCE Alberto PATINO-DOUCE Mazhar QAYYUM Roger L. NIELSEN 《Geostandards and Geoanalytical Research》1994,18(2):195-198
We have developed a set of four synthetic standards for the rare earth and high field strength elements designed for use in the determination of those elements in silicates. The base material is a glass nominally at the eutectic of the MgO-Al2 O3 -SiO2 ternary system. The nominal doping level was 2 wt% of the elements as oxides. To avoid problems associated with peak interference, the elements were doped in four separate glasses. 相似文献