867 resultados para Mines and mineral resources--Australia--Maps
Resumo:
This paper describes a general workflow for the registration of terrestrial radar interferometric data with 3D point clouds derived from terrestrial photogrammetry and structure from motion. After the determination of intrinsic and extrinsic orientation parameters, data obtained by terrestrial radar interferometry were projected on point clouds and then on the initial photographs. Visualisation of slope deformation measurements on photographs provides an easily understandable and distributable information product, especially of inaccessible target areas such as steep rock walls or in rockfall run-out zones. The suitability and error propagation of the referencing steps and final visualisation of four approaches are compared: (a) the classic approach using a metric camera and stereo-image photogrammetry; (b) images acquired with a metric camera, automatically processed using structure from motion; (c) images acquired with a digital compact camera, processed with structure from motion; and (d) a markerless approach, using images acquired with a digital compact camera using structure from motion without artificial ground control points. The usability of the completely markerless approach for the visualisation of high-resolution radar interferometry assists the production of visualisation products for interpretation.
Resumo:
SOLUTIONS (2013 to 2018) is a European Union Seventh Framework Programme Project (EU-FP7). The project aims to deliver a conceptual framework to support the evidence-based development of environmental policies with regard to water quality. SOLUTIONS will develop the tools for the identification, prioritisation and assessment of those water contaminants that may pose a risk to ecosystems and human health. To this end, a new generation of chemical and effect-based monitoring tools is developed and integrated with a full set of exposure, effect and risk assessment models. SOLUTIONS attempts to address legacy, present and future contamination by integrating monitoring and modelling based approaches with scenarios on future developments in society, economy and technology and thus in contamination. The project follows a solutions-oriented approach by addressing major problems of water and chemicals management and by assessing abatement options. SOLUTIONS takes advantage of the access to the infrastructure necessary to investigate the large basins of the Danube and Rhine as well as relevant Mediterranean basins as case studies, and puts major efforts on stakeholder dialogue and support. Particularly, the EU Water Framework Directive (WFD) Common Implementation Strategy (CIS) working groups, International River Commissions, and water works associations are directly supported with consistent guidance for the early detection, identification, prioritisation, and abatement of chemicals in the water cycle. SOLUTIONS will give a specific emphasis on concepts and tools for the impact and risk assessment of complex mixtures of emerging pollutants, their metabolites and transformation products. Analytical and effect-based screening tools will be applied together with ecological assessment tools for the identification of toxicants and their impacts. The SOLUTIONS approach is expected to provide transparent and evidence-based candidates or River Basin Specific Pollutants in the case study basins and to assist future review of priority pollutants under the WFD as well as potential abatement options.
Resumo:
Fifteen iron oxide accumulations from the bottoms of two Finnish lakes ("lake ores") were found to contain as much as 50% Fe. Differential X-ray powder diffraction and selective dissolution by oxalate showed that the samples consisted of poorly crystallized goethite and ferrihydrite. The crust ores of one lake had higher ferrihydrite to goethite ratios than the nodular ores of the other lake. The higher ferrihydrite proportion was attributed to a higher rate of Fe2+ supply from the ground water and/or a higher rate of oxidation as a function of water depth and bottom-sediment permeability. Values of Al-for-Fe substitution of the goethites determined from unit-cell dimensions agreed with those obtained from chemical extraction if the unit-cell volume rather than the c dimension was used. In very small goethite crystals a slight expansion of the a unit-cell dimension is probaby compensated by a corresponding contraction of the c dimension, so that a contraction of the c dimension need not necessarily be caused by Al substitution. The goethites of the two lakes differed significantly in their Al-for-Fe substitutions and hence in their unit-cell sizes, OH-bending characteristics, dehydroxylation temperatures, dissolution kinetics, and Mössbauer parameters. The difference in Al substitution (0 vs. 7 mole %) is attributed to the Al-supplying power of the bottom sediments: the silty-clayey sediments in one lake appear to have supplied A1 during goethite formation, whereas the gravelly-sandy sediments in the other lake did not. The compositions of the goethites thus reflect their environments of formation.
Resumo:
A belt of small but numerous mercury deposits extends for about 500 km in the Kuskokwim River region of southwestern Alaska. The southwestern Alaska mercury belt is part of widespread mercury deposits of the circum Pacific region that are similar to other mercury deposits throughout the world because they are epithermal with formation temperatures of about 200 °C, the ore is dominantly cinnabar with Hg-Sb-As±Au geochemistry, and mineralized forms include vein, vein breccias, stockworks, replacements, and disseminations. The southwestern Alaska mercury belt has produced about 1400 t of mercury, which is small on an international scale. However, additional mercury deposits are likely to be discovered because the terrain is topographically low with significant vegetation cover. Anomalous concentrations of gold in cinnabar ore suggest that gold deposits are possible in higher temperature environments below some of the Alaska mercury deposits. We correlate mineralization of the southwestern Alaska mercury deposits with Late Cretaceous and early Tertiary igneous activity. Our 40Ar/39Ar ages of 70 ±3 Ma from hydrothermal sericites in the mercury deposits indicate a temporal association of igneous activity and mineralization. Furthermore, we suggest that our geological ancl geochemical data from the mercury deposits indicate that ore fluids were generated primarily in surrounding sedimentary wall rocks when they were cut by Late Cretaceous and early Tertiary intrusions. In our ore genesis model, igneous activity provided the heat to initiate dehydration reactions and expel fluids from hydrous minerals and formational waters in the surrounding sedimentary wall rocks, causing thermal convection and hydrothermal fluid flow through permeable rocks and along fractures and faults. Our isotopic data from sulfide and alteration minerals of the mercury deposits indicate that ore fluids were derived from multiple sources, with most ore fluids originating from the sedimentary wall rocks.
Resumo:
Tungsten contents in iron-manganese nodules and crusts from different parts of the World Ocean, as well as its relationships with a number of chemical elements are under consideration. A trend to correlation of tungsten with Fe, Ti, W, Pb, and Co is noticed. Comparison of tungsten contents in the nodules and host sediments indicates its low geochemical mobility.