Uranium and Thorium: The Extreme Diversity of the Resources of the World’s Energy Minerals

Cuney, Michel

doi:10.1007/978-90-481-8679-2_6

Cited by 13 publications

(5 citation statements)

References 94 publications

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“…In intrusive type uranium deposits, the uranium mineralization forms at high temperature in magmatic systems such as pegmatite, alaskite, and granite [1][2][3], and is typically characterized by magmatic uraninite. Uranium-bearing granitic pegmatites mostly occur in [27].…”

Section: Introductionmentioning

confidence: 99%

SIMS U-Pb Dating of Uraninite from the Guangshigou Uranium Deposit: Constraints on the Paleozoic Pegmatite-Type Uranium Mineralization in North Qinling Orogen, China

et al. 2021

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Pegmatite-type uranium mineralization occurs in the Shangdan domain of the North Qinling Orogenic Belt, representing a significant uraniferous province. The Guangshigou deposit is the largest U deposit of the district. Within the North Qinling area, a series of Caledonian granitic igneous rocks intruded the Proterozoic metamorphic rocks of the Qinling Group in two magmatic stages: (i) the Early Silurian Huichizi granite that was derived from a low degree of partial melting of thickened lower basaltic crust combined with mantle-derived materials following the subduction of the Shangdan Ocean; and (ii) the Late Silurian–Early Devonian Damaogou granite and associated pegmatites derived from the same source but emplaced in a late tectonic post-collisional extension environment. In the Guangshigou deposit, the U mineralization mainly occurs as uraninite disseminated in U-rich granitic biotite pegmatites, which formed by assimilation-fractional crystallization magmatic processes. Petrographic observations showed evidence for coeval crystallization of uraninite and other rock-forming minerals of the host pegmatite including quartz, feldspar, biotite, zircon, monazite, apatite, and xenotime. In addition, the low U/Th ratios (~19) and Th, REE, and Y enrichments characterized a magmatic origin for uraninite, which was likely derived from fractionated high-K calc-alkaline pegmatitic magma that experienced various degrees of crustal material contamination. In situ U-Pb isotopic dating performed by Secondary-Ion Mass Spectrometry (SIMS) on uraninite from the Guangshigou deposit yielded a crystallization age of 412 ± 3 Ma, which is concomitant (within errors) with the emplacement age of the host pegmatite (415 ± 2 Ma) and constrained the U ore genesis to the Early Devonian, which corresponds to the late Caledonian post-collisional extension in the North Qinling area. Uraninite then experienced various degrees of metamictization and/or post-Caledonian hydrothermal alteration characterized by an alteration rim associated with coffinite, chlorite and limonite. Finally, the characteristics of the pegmatite-related Guangshigou deposit exhibiting Th-rich uraninite which was the product of assimilation-fractional crystallization of pegmatitic magma defined a model significantly different than the one established for the world-class Rössing deposit characterized by Th-poor uraninite hosted in alaskite dykes formed by low degree of partial melting of U-rich metasediments.

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Section: Introductionmentioning

confidence: 99%

SIMS U-Pb Dating of Uraninite from the Guangshigou Uranium Deposit: Constraints on the Paleozoic Pegmatite-Type Uranium Mineralization in North Qinling Orogen, China

et al. 2021

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“…Considering the radioisotopes uranium and thorium, the high level of eU and eTh are associated with the natural occurrence of the high activity of 238 U and 232 Th in the upper portion of Corumbataí Formation, controlled by its depositional environment (Conceição and Bonotto, 2006;Godoy et al, 2017). Generally, peralkaline magmas are recognized for their effectiveness in enriching uranium (U) and thorium (Th) (Cuney, 2012). In the sedimentary material, the circulation of uids through porous media and the incorporation of uranium and thorium into iron oxides, either derived from detrital iron-titanium sedimentary material or from sur cial processes, represent signi cant factors in uranium and thorium enrichment, as observed in the saprolite layer (Cuney, 2012).…”

Section: Resultsmentioning

confidence: 99%

Applied in-situ gamma-ray spectrometry for evaluating erosion and fertilizer accumulation in the tropical soil around small isolated wetland

Moreira,

Govone,

Marchetti

et al. 2024

Preprint

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Gamma-ray spectrometry has great potential to enhance the understanding of tropical soil properties, including those under intensive agriculture. We utilized gamma-ray spectrometry to assess erosion and the potential accumulation of NPK fertilizer in soil intensively cultivated for sugarcane monoculture, surrounding a small isolated wetland. Conducted in southeastern Brazil, our study involved measurements at 899 soil surface points using gamma-ray spectrometry to detect emissions from radionuclides such as uranium (U238), thorium (Th232), and potassium (K40). Additionally, we measured the hydraulic conductivity (Ksat) at 42 points to evaluate the hydro-physical attributes of the soil surface. The γ-radiation exhibited a close relationship with soil texture, leaching, and prevailing chemical removal. Hydric erosion that affects upslope soil shows high Ksat and very low K. The results indicate that the low K radionuclide contents in the upper soil horizon surrounding the small wetland are attributed to advanced tropical pedogenesis intensified by hydric erosion, with a high correlation with soil texture. The spatial analysis indicates heterogeneity of eU, and to a lesser extent eTh, exhibited levels lower than those found in the parent material, saprolite, and upper soil layers from the weathering profile. This suggests that soluble fertilizers have limited impact on the concentration of the radionuclides in agricultural areas surrounding the small wetland. Significant mobility, particularly of eU, can be associated with pedogenesis. Gamma-spectrometry detected variations in the distribution of the autocorrelated eU and eTh, suggesting a complex bonding with Fe-oxides or clay contents influenced by the small wetland.

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“…A basic precondition, however, for exploration activities to recognize the potential of a geological environment is the presence of favourable geology and creative thinking by the exploration geologist. By way of the example of the two elements uranium and thorium (Cuney 2011 ) , an example of geological considerations is given that illustrates the wide spectrum of mineralization accumulation possibilities. Long et al ( 2011 ) show in a similar way the diverse geological potential for rare earth elements.…”

Section: Physical Availability Of Natural Resourcesmentioning

confidence: 99%

Non-renewable Resource Issues: Geoscientific and Societal Challenges: An Introduction

Sinding-Larsen

Wellmer

2012

Non-Renewable Resource Issues

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This chapter discusses non-renewable resource issues: the raw materials boom of the fi rst decade of the third millennium, availability of a resource (geoscientifi c characteristics), society's dependence on the resource (economic, social and environmental challenges), the gradual dematerialization of advanced economies and the possibility of fi nding alternatives (whether the resource can be substituted or recycled). Assessing important resources against these issues determine their "criticality" and the risk for supply interruptions of e.g. rare-earths and other raw materials needed for industrial products. 'Peaks' in the production of natural resources can be driven by demand or supply. However, fundamental and important differences between a peak in the production of oil and peaks in the production of minerals have been exemplifi ed. Concerning the future availability of natural resources the fi xed stock paradigm is contrasted with the opportunity cost paradigm that takes into account the inherent dynamics of market forces and changing technology. Regardless of paradigm increasing resource effi ciency through human ingenuity and creativity both in the upstream and downstream sector is shown to be vital if mankind is to successfully advance on the road to a sustainable economy based upon transparency and "good governance" that has to be mirrored on the companies' side by corporate social responsibility. The societal aspect is however, only one side of the natural resources coin, the other side being the geological and technical availability.

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Uranium and Thorium: The Extreme Diversity of the Resources of the World’s Energy Minerals

Cited by 13 publications

References 94 publications

SIMS U-Pb Dating of Uraninite from the Guangshigou Uranium Deposit: Constraints on the Paleozoic Pegmatite-Type Uranium Mineralization in North Qinling Orogen, China

SIMS U-Pb Dating of Uraninite from the Guangshigou Uranium Deposit: Constraints on the Paleozoic Pegmatite-Type Uranium Mineralization in North Qinling Orogen, China

Applied in-situ gamma-ray spectrometry for evaluating erosion and fertilizer accumulation in the tropical soil around small isolated wetland

Non-renewable Resource Issues: Geoscientific and Societal Challenges: An Introduction

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