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Xindongzhuang Gold Deposit is located in the middle section of the Zhaoping fault zone, and its ore bodies are mainly distributed along the contact zone between the Mesozoic Linglong granite and Archean Jiaodong Group metamorphic rocks. Beresite is the main mineralized rock. The Linglong granite at the footwall of ore bodies is mainly characterized by red alteration, while the metamorphic rocks in the Jiaodong Group at the hanging wall are marked by propylitization. The main elements analysis reveals the increased contents of K2O, SiO2, SO3, and LOI, which are carried components, in the granite with red alteration, beresite, and sericitolite relative to Linglong granite, in particular for the beresite, and sericitolite that are closely related to mineralization. Among microelements, Rb and U are also commonly carried in the granite with red alteration, beresite, and sericitolite. Gold mineralization at Xindongzhuang Gold Deposit is closely related to changes in oxygen fugacity and acid and alkali conditions, and the enrichment of gold mainly occurs under reductive and slightly acidic conditions. [ABSTRACT FROM AUTHOR]

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Locations used to validate extraction results from remote sensing images are typically ground rock samples. However, remotely sensed image pixels are 30 m2 with mixing spectra. Rock samples cannot fully represent extraction results on an image. Here, alteration information associated with the Águas Claras, Brazil iron deposit was analysed using a Landsat Enhanced Thematic Mapper plus (ETM+), a Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Hyperion data, all with 30 m resolution. With improvements in spectral resolution, extracted results have changed from the alteration information to altered rocks and minerals. The accuracy of alteration information has improved continuously as data extracted from these sources verify one another. Minerals extracted using Hyperion corresponded to altered assemblages identified from ASTER. Both were consistent with alteration information extracted from ETM+ at the same location. Alteration information extracted from three remote images were located within ore formations, and controlled by the north‐east trending faults and matched well with known deposits. Information extraction based on the integrated application of multi‐source remote sensing data could compensate for deficiencies in using single data. These results can verify one another to improve data reliability particularly in the areas inaccessible and lacking sufficient field confirmation. [ABSTRACT FROM AUTHOR]

Abstract: Construction of tunnels in Hokkaido, Japan often excavates rocks containing substantial amounts of arsenic (As) and boron (B). When these rocks are exposed to the environment, As and B are leached out that could potentially contaminate the surrounding soil and groundwater. Natural geologic materials contain minerals like Al-/Fe-oxyhydroxides/oxides that have As and B adsorption capabilities. Because these materials are widespread and readily available, they could be utilized in the mitigation of As and B leached out from these sources. This paper describes the ability of three natural geologic materials (i.e., pumiceous tuffs, partly-weathered volcanic ashes and coastal marine sediments) to sequester As and B from aqueous solutions and the actual leachate of a hydrothermally altered rock. The adsorption of As fitted well with either the Langmuir or Freundlich isotherm while that of B followed the Henry-type model (linear). Among the samples, those containing substantial amorphous Al and Fe exhibited higher As adsorption. However, the distribution coefficient of B only had a moderate positive correlation with these amorphous phases. The best adsorbent among these natural geologic materials was utilized in the adsorption layer of the column experiments. Adsorption of As was more effective the thicker the adsorption layer, but this retardation was only temporary due to significant changes in the pH. In contrast, the adsorption layer only retarded the migration of B to a limited extent. [Copyright &y& Elsevier]

Laboratory reflectance spectra of 18 rock samples from the Precambrian basement of north east of Hajjah were measured and analyzed using the instrument of FieldSpec3 with spectral range 0.250–2.500 µm. The aim of this study is to use the spectral reflectance of rocks for mapping the mineral resources in the north east of Hajjah. The altered system in the study area comprises of silicification, sericitification, oxidation, clay minerals and carbonatization. Silicified alteration is not distinguishable in the regions of Visible-Near Infrared (VNIR) and Short wave Infrared (SWIR) of the electromagnetic spectrum, because of lack of diagnostic spectral absorption features in silica in this wavelength. Although the arsenopyrite and pyrite are wide spread in the whole study area their features do not appear in any range of spectra because they exhibit trans-opaque behavior and often lack distinction in VNIR and SWIR. The entire spectral reflectance curves of samples show alteration. Based on the examination of laboratory spectra all samples in the study area show promise in the field of mineral resources. [ABSTRACT FROM AUTHOR]

A newly discovered Naomugeng lithium mineralization area is located to the east of the Central Asian Orogenic Belt (CAOB). The lithium is hosted in the volcanic rocks of the Manketou'ebo Formation. The altered volcanic rocks mainly consist of quartz, orthoclase, chlorite, montmorillonite, calcite, and dolomite. Here, we present integrated studies of petrography, mineralogy, and geochemistry of the altered volcanic rocks (with an average Li2O content of 0.43 wt.%) collected from the drilling hole and trail trench to systematically investigate the occurrence of lithium, the mineralizing processes, and the metallogenic mechanisms. The secondary minerals of the core samples are montmorillonite, chlorite calcite, and dolomite, while the secondary minerals from the earth surface ones are montmorillonite, chlorite, and calcite. The mass change calculation and isocon analysis show that the rocks received MnO, P2O5, Co, Ni, Cu, and Li and lost Na2O, K2O, MgO, rare earth elements (REE), and Rb in the alteration process. However, other elements such as Fe, V, Co, and Ca of the core samples increased while those of the earth surface ones did not change by much. Hence, there are two zones of alterations, i.e., the montmorillonization-chloritization zone and the montmorillonization-chloritization-carbonatization zone. Lithium enrichment occurs in the zone where montmorillonization and chloritization occur. The lithium is probably enriched in altered minerals such as montmorillonite and chlorite in the forms of interlayered or adsorbed ions. The slightly negative to positive Eu anomalies of the rocks can be explained by the metasomatism of hydrothermal fluid that enriched Eu. We suggest that the Naomugeng deposit is a clay-type lithium deposit and formed under a caldera setting. The meteoric and hydrothermal fluids leach the lithium from the volcanic materials and then alter the host rocks (e.g., tuff or sediments) in the caldera basin, which forms the type of lithium clay deposit. This study analyzed the migration behavior of elements in the Naomugeng lithium deposit during a hydrothermal process, which shows that the mass balance calculation has good application in reflecting the mineralization process of clay type deposit. This study also reveals the great exploration potential of the Naomugeng deposit and has important significance for further prospecting of clay-type lithium deposits in central Inner Mongolia. [ABSTRACT FROM AUTHOR]

Focuses on a study on the hydrogen and oxygen compositions of altered rocks from the Qixia gold deposit in Shandong Province, China and their genetic significance. Sample and analytic methods; Results and discussion; Conclusion.