URANIUM EXPLORATION WITH COMPUTER‐PROCESSED LANDSAT DATA

Geophysics ◽  
1977 ◽  
Vol 42 (3) ◽  
pp. 536-541 ◽  
Author(s):  
Robert K. Vincent

A spectral signature has been constructed for an oxidized topsoil found in the vicinity of near‐surface uranium deposits in porous, arkosic sandstones of the Wind River Basin, Wyoming. A new type of contour map, created from Landsat computer compatible tapes, designed to connect regions of equal percentage of ground area covered by a specified target of interest, was applied to a Landsat frame covering the entire basin. The resulting maps showed relatively high percentages of ground cover by this particular topsoil in regions adjacent to open pit uranium mines in the Gas Hills region, as well as on or near known uranium prospects (as yet undisturbed) in the basin interior. A 10,000-pixel test area west of Lander, Wyoming was found to contain only one pixel (a 0.01 percent recognition rate) identified as the topsoil of interest. However, a whole‐frame recognition map produced a much higher (0.58 percent) recognition rate, indicating that the false alarm rate for this signature is still significantly high, although better than what can be expected from photointerpretation of single ratio images or color composite ratio images. This “signature” has been applied to Landsat frames in other geographical areas with known uranium mines in porous sandstone, and oxidized topsoil has been recognized near these mines.

2021 ◽  
Author(s):  
Kathryn D. Kulju ◽  
Stephen M. McNamara ◽  
Qianjie Chen ◽  
Jacinta Edebeli ◽  
Jose D. Fuentes ◽  
...  

Abstract. The atmospheric multiphase reaction of dinitrogen pentoxide (N2O5) with chloride-containing aerosol particles produces nitryl chloride (ClNO2), which has been observed across the globe. The photolysis of ClNO2 produces chlorine radicals and nitrogen dioxide (NO2), which alter pollutant fates and air quality. However, the effects of local meteorology on near-surface ClNO2 production are not yet well understood, as most observational and modeling studies focus on periods of clear conditions. During a field campaign in Kalamazoo, Michigan from January–February 2018, N2O5 and ClNO2 were measured using chemical ionization mass spectrometry, with simultaneous measurements of atmospheric particulate matter and meteorological parameters. We examine the impacts of atmospheric turbulence, precipitation (snow, rain) and fog, and ground cover (snow-covered and bare ground) on the abundances of ClNO2 and N2O5. N2O5 mole ratios were lowest during periods of lower turbulence and were not statistically significantly different between snow-covered and bare ground. In contrast, ClNO2 mole ratios were highest, on average, over snow-covered ground, due to saline snowpack ClNO2 production. Both N2O5 and ClNO2 mole ratios were lowest, on average, during rainfall and fog because of scavenging, with N2O5 scavenging by fog droplets likely contributing to observed increased particulate nitrate concentrations. These observations, specifically those during active precipitation and with snow-covered ground, highlight important processes, including N2O5 and ClNO2 wet scavenging, fog nitrate production, and snowpack ClNO2 production, that govern the variability in observed atmospheric chlorine and nitrogen chemistry and are missed when considering only clear conditions.


Author(s):  
Hans Tammemagi

Most of the solid waste generated by society ultimately winds up in near-surface landfills. Let us put our thinking caps firmly on, place our prejudices aside, and explore what other methods might be used to dispose of waste. We should seek, in particular, the approaches that best fulfill the three basic principles described in chapter 2. That is, we should strive to find disposal methods that are in accord with sustainable development. Existing and abandoned pits, quarries, and mines are attractive for waste disposal because a hole to contain the wastes has already been excavated. Such abandoned areas, when left unreclaimed, cannot be used for agriculture or other beneficial uses. Thus, they generally do not have significant market value and can often be obtained relatively cheaply. For these reasons, pits and quarries have been extensively used for landfills. Operating and abandoned mines, on which this section focuses, are somewhat similar to pits and quarries, though usually larger. Abandoned mines hold promise as disposal facilities because they are resource areas that have been depleted and thus have little future value. There are two basic types of mine: the open pit mine, which is effectively a large pit or hole in the ground; and the underground mine, where the mined-out openings are deep underground and there is no surface expression except for the shafts used to gain subsurface access. Because underground mines occupy minimal surface land, their use for waste disposal would be in accordance with the sustainable development principles that were advocated in chapter 2. Several European countries, with higher population densities and much smaller land mass than in North America, have long used abandoned underground mines to dispose of their rubbish. The major advantage of placing wastes deep in underground mines is that it is inherently safer than placing the wastes in a surface facility. The amount of groundwater and its flow rate decrease with depth; this fact, combined with the long transport paths back to the biosphere, minimizes the possibility that contaminants will be carried by groundwater to the surface, where they could damage the environment. The waste is contained deeper and more securely.


2019 ◽  
Vol 11 (6) ◽  
pp. 658 ◽  
Author(s):  
James Shepherd ◽  
Pete Bunting ◽  
John Dymond

Image classification and interpretation are greatly aided through the use of image segmentation. Within the field of environmental remote sensing, image segmentation aims to identify regions of unique or dominant ground cover from their attributes such as spectral signature, texture and context. However, many approaches are not scalable for national mapping programmes due to limits in the size of images that can be processed. Therefore, we present a scalable segmentation algorithm, which is seeded using k-means and provides support for a minimum mapping unit through an innovative iterative elimination process. The algorithm has also been demonstrated for the segmentation of time series datasets capturing both the intra-image variation and change regions. The quality of the segmentation results was assessed by comparison with reference segments along with statistics on the inter- and intra-segment spectral variation. The technique is computationally scalable and is being actively used within the national land cover mapping programme for New Zealand. Additionally, 30-m continental mosaics of Landsat and ALOS-PALSAR have been segmented for Australia in support of national forest height and cover mapping. The algorithm has also been made freely available within the open source Remote Sensing and GIS software Library (RSGISLib).


2019 ◽  
Author(s):  
Gary Stewart

New technology has made possible a global survey of martian near-surface meteoritic ore, raising the possibility of precious-metal mining claims. Mars’ history of low-speed asteroid impacts and its enrichment in highly siderophile elements suggest the presence of commercial precious-metal ore within some impact craters. A first Mars base may be sited in a metal-rich crater, to operate as a mining camp. Here an automated facility can leverage a solar panel farm, ice, salts, and hab products and byproducts to extract and refine metals. This “Red Gold” facility can operate in open air, without pressure vessels, and using little consumable cargo from Earth. Practical, illustrative methods are sketched, all aiming to minimize either facility complexity or cargo mass. A foundry can output printed and sintered iron alloy products. A refinery can output not just bullion, but also 3D printed jewelry products, for greater revenue. Daily gold production of just 0.001 m3 can translate into multi-billion-dollar annual revenue from all precious-metal products. This first facility gives a foundation for self-financed mine growth and for martian settlement. However, the socio-political character of settlements would hinge upon ownership of Red Gold; hence upon mining claims. If a totalitarian regime were to secure the claims, the mine and settlements would bear a totalitarian stamp; therefore, a rapid American survey of martian meteoritic ore is recommended and outlined.


Author(s):  
T. Sh. Dalatkazin ◽  
P. I. Zuev

Modern methods for calculating the safety factor of the sides of the open pit do not take into account the parameters of the modern geodynamic activity of the instrument array. The article presents the results of the first stage of research on the unique capabilities of radonometry to solve this problem. The studies were carried out in the instrument areas of the Shubarkol coal deposit. Terrigenous-carbonate sediments represented by fine and coarse-grained sandstones, siltstones, mudstones, loamy rocks and coals take part in the geological structure of the deposit. The stress-strain state of the rock massif in the area of the Shubarkulsky coal deposit is very heterogeneous. The nature of the deformation processes of the sides of the section is constant and moderate. Here, a discrete distribution of deformation sections is characteristic. The article presents the methods of radonometric measurements, the processing of measurement results and the results of studies of the near-surface sections of a coal mine, aimed at developing a methodology for quantitatively taking into account the degree of modern geodynamic activity in the design of open pit sides. Based on the results of radonometry, the geodynamic activity indices identified in the study of the deformation zones of the instrumentation areas are determined. An algorithm for further studies of the problem of taking into account the degree of modern geodynamic activity in determining the safety margin of open pit sides is determined.The accumulation and generalization of empirical information about the deformation processes of open pits and the results of studies of the geodynamic situation of dash sites, determined using radonometry, will make it possible to modernize the methodology for calculating the margin of safety margin of the sides.


Author(s):  
Narasimman Sundararajan ◽  
Bernhard Pracejus ◽  
Salah Al- Khirbash ◽  
Talal Al-Hosni ◽  
Ala Ebrahimi Ebrahimi ◽  
...  

The Proterozoic basement of the Dhofar region of the Sultanate of Oman might be considered as a potential source of Uranium mineralization like other Proterozoic basins of the world, which collectively contribute 30%-40% to the global production.  Uranium exploration assumes great importance in this part of the world and therefore geochemical and geophysical exploration for Uranium was initiated.  Initial, random sampling of the study area with Gamma ray spectrometry as well as in situ XRF (Xray Florescence) analysis indicated the presence of   around 30-40 ppm of Uranium. Since Gamma ray spectrometry results in the calculation of the heat produced during radioactive decay of Potassium (K), Uranium (U) and Thorium (Th) within the rocks in the study area, measurements were acquired along eleven traverses of varying length from 100-250 m at a traverse interval of 20 m and sampling interval of 10 m. Individual plots of the concentrations  of radioelements such as U, K and Th have shown favorable anomalous radioactive sources. Besides this, Uranium to Thorium (eU/eTh) and Uranium to Potassium (eU/K) ratio plots have been presented and the alteration zones associated with Uranium mineralization through all traverses have been identified. Further, the generated composite ternary image based on the combination of K, Th and U from Gamma ray spectrometry determines different relative amounts of radioelements and paves the way for deciphering the level of radioactivity in the study area. However, there seems to be no presence of strong Uranium anomalies in the near surface of the limited study area. As the study area is heavily faulted, the depth to concealed  subsurface fault structures  is  estimated to be around  64 m based on Hartley spectral analysis of total magnetic anomaly (line-6). 


2019 ◽  
Vol 1 (1) ◽  
pp. 279-288
Author(s):  
Ekaterina Sitnikova ◽  
Sergey Ozhigin ◽  
Dmitry Kulygin
Keyword(s):  
Open Pit ◽  

The article describes the development of a project of observation stations designed to monitor the state of the near-surface arrays in the open pit “Karakomir”, as well as the analysis of their deformations.


2020 ◽  
Vol 1 (1) ◽  
pp. 585-594
Author(s):  
Hifzil Kirmi ◽  
Muhammad Masyhuri

ABSTRAK Kegiatan penambangan batu bara PT Berau Coal site Lati menggunakan teknik open pit mining yang mana salah satu pengaruh negatif dari kegiatan operasional yakni potensi terjadinya pencemaran lingkungan meliputi pencemaran air karena terjadi erosi dan sedimentasi sungai dan juga terbentuknya areal revegetasi dengan tingkat kesuburan yang rendah. Untuk mengurangi dampak negatif salah satunya dengan penanaman mengguankan teknologi hydroseeding. Metode yang digunakan adalah penilaian keberhasilan covering covercrop hydroseeding dengan ground cover assassment, pendugaan laju erosi dengan USLE dan analisa kesuburan tanah kandungan pH dan C/N rasio. Hasil penelitian menunjukan areal revegetasi yang belum ditumbuhi covercrop mempunyai laju erosi sangat tinggi dan kesuburan tanah yang rendah, sedangkan pada areal yang sudah ditanamai covercrop dengan teknologi hydroseeding mempunyai tingkat laju erosi rendah dan kesuburan tanah yang senderung meningkat serta keberhasilan penutupan covercrop yang tinggi pada lahan marginal. Kata kunci : hydroseeding, lahan marginal, erosi, tanah  ABSTRACT PT Berau Coal site Lati coal mining activities use open pit mining technique, which is one of the negative effects of operational activities, namely the potential for environmental pollution including water pollution due to erosion and sedimentation of the river and also the formation of revegetation areas with low fertility. To reduce the negative impacts, one of them is by planting using hydroseeding technology. The method used is an assessment of the success of covering cover crop hydroseeding with ground cover assassment, estimating the rate of erosion with USLE and analyzing soil fertility with pH and C / N ratio. The results showed revegetation areas that have not been covered with covercrop have very high erosion rates and low soil fertility, whereas in areas that have been planted with covercrop with hydroseeding technology have low erosion rates and soil fertility which is inclined to increase and the success of covercrop cover is high on land marginal. Keywords: hydroseeding, marginal land, erosion, soil


2005 ◽  
Vol 71 (4) ◽  
pp. 1790-1797 ◽  
Author(s):  
Yohey Suzuki ◽  
Shelly D. Kelly ◽  
Kenneth M. Kemner ◽  
Jillian F. Banfield

ABSTRACT The fate of uranium in natural systems is of great environmental importance. X-ray absorption near-edge spectroscopy (XANES) revealed that U(VI) was reduced to U(IV) in shallow freshwater sediment at an open pit in an inactive uranium mine. Geochemical characterization of the sediment showed that nitrate, Fe(III), and sulfate had also been reduced in the sediment. Observations of the sediment particles and microbial cells by scanning and transmission electron microscopy, coupled with elemental analysis by energy dispersive spectroscopy, revealed that uranium was concentrated at microbial cell surfaces. U(IV) was not associated with framboidal pyrite or nanometer-scale iron sulfides, which are presumed to be of microbial origin. Uranium concentrations were not detected in association with algal cells. Phylogenetic analyses of microbial populations in the sediment by the use of 16S rRNA and dissimilatory sulfite reductase gene sequences detected organisms belonging to the families Geobacteraceae and Desulfovibrionaceae. Cultivated members of these lineages reduce U(VI) and precipitate iron sulfides. The association of uranium with cells, but not with sulfide surfaces, suggests that U(VI) is reduced by the enzymatic activities of microorganisms. Uranium was highly enriched (760 ppm) in a subsurface black layer in unsaturated sediment sampled from a pit which was exposed to seasonal fluctuations in the pond level. XANES analysis showed that the majority of uranium in this layer was U(IV), indicating that uranium is preserved in its reduced form after burial.


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