The extreme diversity of uranium deposits

Most available classifications of uranium deposits are based on the characteristics of the host rocks or on the morphology of the ore deposits. The aim of the present paper is to propose the basis for a genetic classification of these deposits. After a short introduction on the geochemical behavior of uranium in fluids and silicate melts and on the main uranium fractionation mechanisms operating in uranium-rich peraluminous, metaluminous, and peralkaline melts, the most recent metallogenic models of the main types of uranium deposits are shortly reviewed.     

Probabilistic life cycle analysis model for evaluating electric power infrastructure risk mitigation investments

One effect of climate change may be increased hurricane frequency or intensity due to changes in atmospheric and geoclimatic factors. It has been hypothesized that wetland restoration and infrastructure hardening measures may improve infrastructure resilience to increased hurricane frequency and intensity. This paper describes a parametric decision model used to assess the tradeoffs between wetland restoration and infrastructure hardening for electric power networks. We employ a hybrid economic input–output life-cycle analysis (EIO-LCA) model to capture: construction costs and life-cycle emissions for transitioning from the current electric power network configuration to a hardened network configuration; construction costs and life-cycle emissions associated with wetland restoration; and the intrinsic value of wetland restoration. Uncertainty is accounted for probabilistically through a Monte Carlo hurricane simulation model and parametric sensitivity analysis for the number of hurricanes expected to impact the project area during the project cycle and the rate of wetland storm surge attenuation. Our analysis robustly indicates that wetland restoration and undergrounding of electric power network infrastructure is not preferred to the “do-nothing” option of keeping all power lines overhead without wetland protection. However, we suggest a few items for future investigation. For example, our results suggest that, for the small case study developed, synergistic benefits of simultaneously hardening infrastructure and restoring wetlands may be limited, although research using a larger test bed while integrating additional costs may find an enhanced value of wetland restoration for disaster loss mitigation.     

Automated Image Registration for Hydrologic Change Detection in the Lake-Rich Arctic

Multitemporal remote sensing provides a unique tool to track lake dynamics at the pan-Arctic scale but requires precise registration of thousands of satellite images. This is a challenging task owing to a dearth of stable features to be used as tie points [(TPs), i.e., control points] in the dynamic landscapes. This letter develops an automated method to precisely register images in the lake-rich Arctic. The core premise of the method is that the centers of lakes are generally stable even if their shorelines are not. The proposed procedures first extract lakes in multitemporal satellite images, derive lake centroids and match them between images, and then use the centroids of stable lakes as TPs for image registration. The results show that this approach can achieve subpixel registration accuracy, outcompeting the conventional manual methods in both efficiency and accuracy. The proposed method is fully automated and represents a feasible way to register images for lake change detection at the pan-Arctic scale.      

Numerical modeling of the Rideau Valley Watershed

Using the Mike11 modeling system by the Danish Hydraulic Institute, a detailed model of the Rideau Valley Watershed was constructed. It includes 532 km of rivers and lakes, 106 basins, 122 bridges and culverts, and 20 water control structures. The model was calibrated using measured streamflow data for a time period of 5 years; additional 5 years of data was used for validation. Various methods, both qualitative and quantitative, were used to evaluate the model performance. It was found that the model can simulate the hydrological response with a reasonable to high degree of accuracy. This model is now being used for various watershed management purposes, including flood forecasting, dam safety assessment, quantification of wetland functions, and derivation of design flows.     

Application of electrical and electromagnetic methods to study sedimentary covers in high mountain areas

The results of geophysical studies conducted with selected electrical and electromagnetic methods in the Kondratowa Valley in the Tatra Mountains (the Carpathian Mountains, Poland) are presented in the article. The surveys were performed with the following methods: electrical resistivity tomography (ERT), georadar (GPR) and conductivity meter (CM). The objective of the noninvasive geophysical measurements was to determine the thickness of the Quaternary postglacial sediments that fill the bottom of the valley and to designate the accumulation of boulders deposited on Quaternary sediments. The results of ERT surveys conducted along the axis of the valley allowed to determine the changeability of the thickness of the postglacial sediments and allowed to designate a few areas of occurrence of boulders. The ERT, GPR and CM surveys conducted across the valley allowed to designate with high accuracy the thickness of the accumulation of boulders sliding down the valley bottom from the couloirs surrounding the valley.     

Iron ore workings near Horsham,Sussex, and the sedimentology of Wealden clay ironstone

The distribution of old workings, or ‘minepits’, for clay ironstone in an area between Horsham and Crawley is shown on geological sketch-maps. The geological structure of the area is described in outline. The old workings, except for those in two anomalous patches, are restricted to two argillaceous units in the Upper Tunbridge Wells Sand and to an ironstone horizon some 2 m. below the Horsham Stone in the Weald Clay. Slags from two bloomery sites are described. The amount of ore dug from the minepits is estimated to correspond roughly to the requirements of local blast furnaces, of sixteenth- and seventeenth-century date. Depletion of iron ore reserves is suggested as a factor deciding against resumption of the iron industry in the area after the Civil War.     

Zinc content in otoliths of mackerel from the Aegean

The zinc content in otoliths of the mackerel (Scomber japonicus colias) has been determined by instrumental neutron activation analysis. Six groups each of twelve specimens of the same age selected from three areas of the Aegean sea have been analysed. The zinc content was found to be a linear function of the age and body length.     

Geordnete Deponie von festen Siedlungs- und geeigneten Industrieabfällen

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