Concentrations of contaminants in surface water samples collected in west-central Indiana impacted by acidic mine drainage

The results of analyses of surface waters collected from a variety of locations in west-central Indiana indicate extensive contamination by acidic mine drainage. These samples had pH values as low as 2.1 and total iron concentrations as high as 1200 mg1^–1. The speciation of iron, expressed as the ratio [Fe(II)]/[Fe(III)] ranged from 0.08 to 8.27. Measured lead concentrations were as high as 811 mgl^–1. In addition, the concentrations of nitrate and sulfate ions were as high as 359 and 624 mgl^–1, respectively.     

Fractal properties of multi-order folding as a tool for exploration of low-grade banded iron ores in the Krivoy Rog basin (Ukraine)

The low-grade Palaeoproterozoic stratabound banded iron ores of the Krivoy Rog basin (Ukraine) underwent strong tectonometamorphic deformation into superimposed folds of several orders, with amplitudes from centimetres to hundreds of metres. The across-strike sections of bed surfaces defining the low-grade ore bodies resemble self-similar fractal curves; hence, a fractal geometrical model was developed in order to quantify the complexity and sinuosity of bed contours. Two different methods of measurement (polygonal approximation and two-dimensional grid cell counting) were used for 5–8 different scales. Factual similarity dimension D and other model parameters have been estimated by means of linear regression and compared for both measurement methods. From the fractal model a sinuosity coefficient of contours of the folded bed surfaces K _s and a coefficient of degree of exploration of iron ore bodies K _e were constructed. It is pointed out that parameters of the model can be used for determination of the optimal exploration length scales.     

内蒙东乌旗石铁陨石

１９９５年９月７日下午１时４５分在内蒙古东乌珠穆沁旗、呼热图苏木、阿日斯楞图嘎查地区（４５°３０＇Ｎ，１１９°Ｅ）陨落了各相距１０ｋｍ的三块陨石，分别编号为Ｎｏ．１、Ｎｏ．２和Ｎｏ．３，其重量分别为８８．２，３８．０和２．６ｋｇ。三块陨石表面的熔壳发育程度不一，Ｎｏ．２和Ｎｏ．３熔壳发育，Ｎｏ．１不良育，表明是经历了二次爆裂破碎的结果。据肉眼观察，陨石中金属矿物和非金属矿物分布不均一，它们聚集成大     

多源遥感影像的去云层处理

针对多源遥感影像的云覆盖问题，提出了利用多项式改正算法，以实现不同遥感影像之间的局部影像替换，从而满足去除目标影像上云覆盖的要求。     

大冶铁矿废石场复垦及矿区可持续发展研究--以尖山废石场为例

大冶铁矿历史悠久 ,是武钢的主要矿石原料基地 ,目前的生产能力为每年 44 0万 t,长期的矿产开发创造了巨大的财富 ,也破坏了自然环境和生态系统 :尾矿库、废石场和采空区占用和破坏土地超过 3333333m2 ,矿区周围的水和土壤被污染。要改善生态环境 ,缓解矿区人多地少的矛盾 ,追求矿山的可持续发展 ,土地复垦迫在眉睫。针对尖山废石场现状及复垦适宜性等问题 ,在野外调研和取样分析的基础上 ,着重对废石场的农业复垦进行了规划和技术、经济评价 ,并提出了采用淤泥覆土的观点。同时对矿山土地复垦工作在资金、人力、工程技术等方面提出了一些建议。     

岩石全分析数据中Fe2O3与FeO的调整及其微机程序

由于多种原因,往往造成岩石化学全分析数据中部分FeO由于化验中处理而转变为Fe_2O_3,使岩石中原有铁的氧化态发生变化。如不加以调整,会在岩石化学全分析结果使用上出现严重不良后果,甚至在判别岩石化学性质及岩石形成条件等方面会得出错误结论。在此提醒对这一问题的注意,并介绍如何具体调整铁氧化态的方法及其微机程序。     

长江口潮滩沉积物氧化铁与磁性特征的关系

通过对长江口潮滩沉积物以连二亚硫酸钠－柠檬酸纳－重碳酸钠（DCB）、避光草酸铵（AOD）提取方法进行的氧化铁分析以及磁性测量，探讨了氧化铁与磁性参数的关系，提出了不同类型氧化铁含量估算方法，并分析了DCB提取对全样及分粒级样品磁性特征的影响。结果显示，磁化率及饱和等温剩磁与游离氧化铁和无定形铁含量之间存在显著的相关性。对不同类型氧化铁含量的半定量估算显示，长江口潮滩沉积物中以无定形铁占绝对优势，磁铁矿仅占游离氧化铁的12％左右。DCB提取对磁性特征的影响依赖于磁性矿物晶粒大小和含量。DCB试剂不仅能提取小于2μm粒级中的细晶粒氧化铁，还能溶解相当一部分粗晶粒磁铁矿。此外，根据DCB提取前后S－100及硬剩磁的变化，表明粘土中更富集不完整反铁磁性氧化铁。     

Uranium isotopic evidence for the origin of the Bahariya iron deposits, Egypt

The economic iron ore deposits of Egypt are located at Bahariya Oasis in the Lower Middle Eocene limestone. The main iron minerals are goethite, hematite, siderite, pyrite, and jarosite. Manganese minerals are pyrolusite and manganite. Gangue minerals are barite, glauconite, gibbsite, alunite, quartz, halite, kaolinite, illite, smectite, palygorskite, and halloysite. Geochemical comparison between the ore and the Nubia sandstone showed that the ore is depleted in the residual elements (Al, Ti, V, and Ni) and enriched in the mobile elements (Fe, Mn, Zn, Ba, and U) which indicates that the Bahariya iron ore is not a lateritic deposit despite the deep weathering in this area. On the other hand, the Nubia sandstone showed depletion in the mobile elements, which demonstrates the leaching process in the Nubia Aquifer. The presence of such indicator minerals as jarosite, alunite, glauconite, gibbsite, palygorskite, and halloysite indicate that the ore was deposited under strong acidic conditions in fresh water.Isotopic analyses of the uranium in the amorphous and crystalline phases of the ore, in the country rocks, and dissolved in the Nubia Aquifer water, all support the conclusion that U and Fe were precipitated together from warm ascending groundwater. U and Fe display strong co-variation in the ore, and the ²³⁴U/²³⁸U activity ratio of the newly precipitated U in the country rock and the leached component of U in the groundwater are identical. There is only slightly more uranium in the amorphous phase than in the crystalline and only a slightly lower ²³⁴U/²³⁸U activity ratio, suggesting that the iron in the two phases have a similar origin. Comparison of the excess ²³⁴U in the water and in the total ore leads to the conclusion that the precipitation of the U, and by inference the iron, occurred within the last million years. However, that both precipitation and leaching of U have occurred over the last 300,000 years is evidenced by the extreme ²³⁰Th/²³⁴U disequilibria observed in some of the samples. Some of the amorphous depositional events have been very recent, perhaps within the last 10,000 years.     

Pinus brutia as a biogeochemical medium to detect iron and zinc in soil analysis, chromite deposits of the area Mersin, Turkey

Soil and pine (Pinus brutia) samples were collected from 64 sites over chromite and ultramafic rocks near Musal?, and over clastic sediments of the Silifke-Anamur areas of Mersin, Turkey. Both sample media were analyzed for their Zn and Fe contents. The results showed similar concentration of both elements in the ash of needles and twigs, with each exhibiting lower concentration than the soils. Zinc was more concentrated in pines from the Silifke-Anamur area than at Musal?, but Fe concentrations were similar in both area. A positive correlation was observed between Zn and Fe in pine and soils (r=0.90 and 0.79, respectively). It is concluded that P. brutia can be used as a biogeochemical sample medium to detect concealed deposits of Zn and Fe.     

Closure of the Fe-S-Si liquid miscibility gap at high pressure

A high pressure investigation of melting relationships in the Fe-S-Si system has been conducted in a multi-anvil apparatus from 10 to 27 GPa and up to 2343 K. At 1 atm, the Fe-S-Si ternary system exhibits a vast miscibility gap [Raghavan, V., 1988. Phase diagrams of ternary iron alloys. Part 2: Ternary systems containing iron and sulphur. Indian Institute of Metals, Calcutta]. Quenched samples from experiments conducted at 10 and 12 GPa show an emulsion of immiscible liquids (an Fe-S melt and an Fe-Si melt). The liquid miscibility gap persists to at least 2343 K at 10 GPa. At 15 GPa, only one liquid is quenched, with a fine homogeneous dendritic texture. The results provide a mechanism to incorporate both S and Si as the light elements into the Earth’s core during a moderately high-pressure differentiation, consistent with geochemical models predicting up to 15 wt.% of light elements in the Earth’s core with 2-5 wt.% S and 7-10 wt.% Si. In contrast, for small planets such as Mars and Ganymede, differentiation took place within the pressure range of the miscibility gap. The composition of these cores is likely to be S-rich but Si-poor.