Uranium evolution

Oxygen and nitrogen also are deterrnined by conductivity or chromatographic techniques following a hot vacuum extraction or inert-gas fusion of hafnium with a noble metal (25,26). Nitrogen also may be deterrnined by the Kjeldahl technique (19). Phosphoms is determined by phosphine evolution and flame-emission detection. Chloride is determined indirecdy by atomic absorption or x-ray spectroscopy, or at higher levels by a selective-ion electrode. Fluoride can be determined similarly (27,28). Uranium and U-235 have been determined by inductively coupled plasma mass spectroscopy (29). 

The mechanisms of corrosion by steam are similar to those for water up to 450°C, but at higher temperatures are more closely related to the behaviour in carbon dioxide. Studies at 100°C have demonstrated that uranium hydride is produced during direct reaction of the water vapour with the metal and not by a secondary reaction with the hydrogen product. Also at 100°C it has been shown that the hydride is more resistant than the metal. Inhibition with oxygen reduces the evolution of hydrogen and does not involve reaction of the oxygen with the uranium . Above 450°C the hydride is not... 

O Hara MJ (1968) The bearing of phase equilibria studies in synthetic and natural systems on the origin and evolution of basic and ultrabasic rocks. Earth Sci Rev 4 69-133 O Nions RK, McKenzie D (1993) Estimates of mantle thorium/uranium ratios from Th, U and Pb isotope abundances in basaltic melts. Phil Trans Royal Soc 342 65-77 Oversby V, Gast PW (1968) Lead isotope compositions and uranium decay series disequilibrium in reeent volcanic rocks. Earth Planet Sci Lett 5 199-206... 

Atkinson TC, Rowe PJ (1992) Applications of dating to denudation chronology and landscape evolution. In Uranium-series disequilibriiun Applications to Earth, Marine and Enviromnental Sciences, Ivanovich M, Harmon RS (eds) Oxford University Press, Oxford, p 669-703 Auler AS, Smart PL (2001) Late Quaternary paleoclimate in semiarid Northeastern Brazil from U-series dating of travertines and water table speleothems. Quat Res 55 159-167 Ayliffe LK, Marianelh PC, Moriarty KC, Wells RT, McCulloch MT, Mortimer GE, Hellstrom JC (1998) 500 ka precipitation record from southeastern Australia Evidence for interglacial relative aridity. Geology 26 147-150... 

Bones and teeth, however, are primary archaeological materials and are common to many archaeological sites. Bones bearing cut marks from stone tools are a clear proxy for human occupation of a site, and in the study of human evolution, hominid remains provide the primary archive material. Hence, many attempts have been made to directly date bones and teeth using the U-series method. Unlike calcite, however, bones and teeth are open systems. Living bone, for example, contains a few parts per billion (ppb) of Uranium, but archaeological bone may contain 1-100 parts per million (ppm) of Uranium, taken up from the burial environment. Implicit in the calculation of a date from °Th/U or Pa/ U is a model for this Uranium uptake, and the reliability of a U-series date is dependent on the validity of this uptake model. 

Szabo BJ, Rosholt JN (1969) Uranium-series dating of Pleistocene molluscan shells from southern California - an open system model. J Geophys Res 74 3253-3260 Thome A, Griin R, Spooner NA, Simpson JJ, McCulloch M, Cumoe D (1999) Australia s oldest human remains age of the Lake Mungo 3 skeleton. J Human Evol 36 591-612 Wolpoff M (1989) Multiregional evolution the fossil alternative to Eden. In The Human Revolution. 

Though this chapter is focused on the °Th/U method, most of the concepts are directly applicable to other uranium-series chronometers, such as Pa/ U, Pa/ Th or Ra/ Mh. However, because the details of individual applications of these methods are more varied than for the Th/U method, and in some cases can be expected to evolve significantly (e.g., coupled Pa- °Th evolution Cheng et al. 1998), they will not be specifically addressed here. 

There are seven naturally occurring radioactive elements from uranium, the elements are all unstable and were prepared artificially. This is an astonishing phenomenon. Not only did evolution produce a being that was in the position to discover the Periodic Table, it gave it the ability to produce elements that do not exist in nature. Needless to say, we shall not go any deeper into this aspect of natural philosophy. 

Dubrovsky N.M., Cherry J.A., Reardon E.J., Vivyurka, A.J. 1985. Geochemical evolution of inactive pyritic tailings in the Elliot Lake uranium district. Canadian Geotechnical Journal, 22, 110-128. 

In the light of the projected growth of demand for energy services, particularly electricity, there is a renewed interest in the extension of nuclear power in some countries. With uranium being a finite resource as well, Chapter 4 focuses primarily on the question of a future expansion of nuclear power in the context of the availability of nuclear fuels. Moreover, the evolution of the next generation of nuclear reactors, such as breeder reactors or reactors suitable for hydrogen production, is addressed. 

PoLiTO, P.A., Kyser, T.K., Marlatt, J., Alexandre, P., Bajwah, Z., Drever, G. 2004. Significance of alteration assemblages for the origin and evolution of the Proterozoic Nabarlek unconformity-related uranium deposit. Northern Territory, Australia. Economic Geology, 99, 111-139. 

Alexandre, P., Kyser, K., Thomas, D., Polito, P., Marlat, J. 2009. Geochronology of unconformity-related uranium deposits in the Athabasca Basin, Saskatchewan, Canada and their integration in the evolution of the basin. Mineralium Deposita, 44, 41-59. Annesley, I.R., Madore, C., Portella, P. 2005. Geology and thermotectonic evolution of the western margin of the Trans-Hudson Orogen evidence from the eastern sub-Athabasca basement, Saskatchewan. Canadian Journal of Earth Sciences, 42, 573-597. 

The two distinct types of mineralization at Cage could reflect the evolution of uranium from the initial trapping in epicontinental platform sediments to the remobilization by metamorphic processes in a collisional orogen ... 

CuNEY, M.l. 2007. Evolution recente des recherohes sur la metallogenese de I uranium. Geologues, 152, 52-62. 

Combes, J.M. (1988) Evolution de la structure locales des polymeres et gels ferriques lors de la crystallization de oxydes de fer. Application au piegeage de I uranium. Ph.D. Thesis Univ. Paris VI., 206 p. 

Waugh, W. J., Smith, G. M., Bergman-Tabbert, D. Metzle, D. R. 2001. Evolution of cover systems for the Uranium Mill Tailings Remedial Action Project, USA. Mine Water and the Environment, 20, 190-197. 

Fig. 13. Evolution of the pe and pH of waters along the flow paths suggested from the hydrogeological analysis of the Cigar Lake site. Thermodynamic database for uranium from Grenthe et al. (1992) and Bruno Puigdomenech (1989). (a) Uranium modelling. Equilibrium assumption. Evolution from borehole 220. (b) Uranium modelling. Equilibrium assumption. System evolving from borehole 211.

Bruno, J., Casas, I., Cera, E., Swing, R. C., Finch, R. C. Werme, L. O. 1995. The assessment of the long-term evolution of the spent nuclear fuel matrix by kinetic, thermodynamic and spectroscopic studies of uranium minerals. Materials Research Society Symposium Proceedings, 353, 633-639. 

The common-lead method looks at the isotopic evolution of lead in systems with U/Pb and Th/Pb ratios similar to or less than the ratios in bulk solar system materials. The original formulation, by Holmes and Houtermans, is a single stage model that accounts for the isotopic composition of any sample of common lead in terms of primordial lead plus radiogenic lead produced in the source up to the time that lead was separated from uranium and thorium. Multistage models that more accurately describe the evolution of natural systems have been developed. The common-lead method is used in cosmochemistry primarily to study the time of differentiation and reservoir evolution in differentiated bodies... 

The intrinsic properties of carbonaceous materials (ubiquity, variety of genetical types, fair resistance to geological agents, plasticity or brittleness, adsorption of uranium, metamorphic evolution) added to their sensitivity to... 

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