scholarly journals The role of graphite in the formation of unconformity-related uranium deposits of the Athabasca Basin, Canada: a case study of Raman spectroscopy of graphite from the world-class Phoenix uranium deposit

2021 ◽  
1989 ◽  
Vol 26 (3) ◽  
pp. 490-498 ◽  
Author(s):  
T. K. Kyser ◽  
M. R. Wilson ◽  
G. Ruhrmann

The Key Lake unconformity-type uranium deposit occurs in a shear zone where it intersects the unconformity between Archean and Aphebian gneisses and the overlying Proterozoic Athabasca Group sandstones. The roots of the Key Lake and many other unconformity-type uranium deposits in the Athabasca basin are close to gneisses rich in graphite and most deposits have small amounts of carbonaceous materials (bitumen and hydrocarbon buttons) within and around altered basement and sandstone ore zones. In many Athabasca uranium deposits, hydrothermal fluids have destroyed graphite disseminated in the strongly altered gneisses in the vicinity of the deposits, prompting some to suggest that graphite was converted to CH4, which reduced and precipitated the uranium and partially condensed to form bitumen. The δ13C values of graphite collected from unaltered and altered gneisses around the Key Lake deposit have a limited range (−25 ± 5) and are not a function of distance from the mineralization or the intensity of alteration or deformation. The uniformity of these δ13C values suggests that the destruction of graphite was due predominantly to oxidation by basinal fluids from the sandstone and that the graphite near the deposits did not react to form substantial amounts of 12C-rich phases such as CH4. Most of the bitumen samples, which have higher H/C ratios than the graphite, have δ13C values identical to those of the graphite (−25 ± 5). The similarity in the isotopic compositions of carbon in the bitumen and in the graphite indicates that the bitumen formed from degradation of graphite as a result of reactions with no significant isotopic fractionations, such as ones involving radiolysis of graphite. The hydrocarbon buttons and a few samples of bitumen have petrographic relations and 13C/12C ratios (δ13C values less than −30) that are indicative of reduction of graphite by H2 produced from water by radiolysis. Graphite in these deposits did not play a central role as a reducing agent for uranium, rather it represents a critical structural factor by providing shear zones along which fluid flow can be focussed.


Author(s):  
Michael W. Pratt ◽  
M. Kyle Matsuba

Chapter 6 reviews research on the topic of vocational/occupational development in relation to the McAdams and Pals tripartite personality framework of traits, goals, and life stories. Distinctions between types of motivations for the work role (as a job, career, or calling) are particularly highlighted. The authors then turn to research from the Futures Study on work motivations and their links to personality traits, identity, generativity, and the life story, drawing on analyses and quotes from the data set. To illustrate the key concepts from this vocation chapter, the authors end with a case study on Charles Darwin’s pivotal turning point, his round-the-world voyage as naturalist for the HMS Beagle. Darwin was an emerging adult in his 20s at the time, and we highlight the role of this journey as a turning point in his adult vocational development.


Author(s):  
Ekaterina Savitskaya ◽  

In the field of cognitive linguistics it is accepted that, before developing its capacity for abstract and theoretical thought, the human mind went through the stage of reflecting reality through concrete images and thus has inherited old cognitive patterns. Even abstract notions of the modern civilization are based on traditional concrete images, and it is all fixed in natural language units. By way of illustration, the author analyzes the cognitive pattern “сleanness / dirtiness” as a constituent part of the English linguoculture, looking at the whole range of its verbal realization and demonstrating its influence on language-based thinking and modeling of reality. Comparing meanings of language units with their inner forms enabled the author to establish the connection between abstract notions and concrete images within cognitive patterns. Using the method of internal comparison and applying the results of etymological reconstruction of language units’ inner form made it possible to see how the world is viewed by representatives of the English linguoculture. Apparently, in the English linguoculture images of cleanness / dirtiness symbolize mainly two thematic areas: that of morality and that of renewal. Since every ethnic group has its own axiological dominants (key values) that determine the expressiveness of verbal invectives, one can draw the conclusion that people perceive and comprehend world fragments through the prism of mental stereo-types fixed in the inner form of language units. Sometimes, in relation to specific language units, a conflict arises between the inner form which retains traditional thinking and a meaning that reflects modern reality. Still, linguoculture is a constantly evolving entity, and its de-velopment entails breaking established stereotypes and creating new ones. Linguistically, the victory of the new over the old is manifested in the “dying out” of the verbal support for pre-vious cognitive patterns, which leads to “reprogramming” (“recoding”) of linguoculture rep-resentatives’ mentality.


2009 ◽  
Vol 30 (1) ◽  
pp. 113-129 ◽  
Author(s):  
Michael Nitz ◽  
Øyvind Ihlen ◽  
Jessyna Egge ◽  
Stacy Sobolik

Abstract The U.S. Presidential election of 2004 was an exciting reprise of the 2000 election and was closely watched by numerous observers across the world. The election held significant ramifications for world issues such as the war in Iraq and the war on terror. Norwegian media in particular followed the election with great interest. The strong social and familial bond between Norwegians and Americans was a foundation for an interest in the role that social issues such as abortion, gay marriage, and religion played in the campaign. This article was an exploratory case study based on data from three major Norwegian newspapers. The article used framing theory as a tool to examine the way in which these newspapers covered the 2004 U.S. Presidential election. A key focus was the importance and influence of culture in this framing process. Results are presented and implications for the role of framing theory in international contexts are discussed.


Author(s):  
Daniel Peter Ferguson ◽  
Guoxiang Chi ◽  
Charles Normand ◽  
Patrick Ledru ◽  
Odile Maufrais-Smith

The Athabasca Basin in northern Saskatchewan is host to many world-class uranium deposits associated with the unconformity between the Paleoproterozoic sandstone of the basin and the underlying crystalline basement (Jefferson et al., 2007).  While the style and tonnage of these deposits vary, the current genetic model for unconformity-related uranium deposits has been a practical tool for exploration in the Athabasca Basin. However, the factors which control the location and formation of these deposits is still not fully understood. A paragenetic and petrographic study of mineralization along the Midwest Trend, located on the northeastern margin of the Athabasca Basin, aims to refine the current model and to address the general problem: What are the factors which control mineralization and non-mineralization? The Midwest Trend will be used as a "modèle réduit" for uranium mineralization, as it displays many features characteristic of unconformity type deposits. The Midwest Trend comprises three mineral leases that encompass two uranium deposits, the Midwest Main and Midwest A (Allen et al., 2017a, b). Mineralization occurs along a NE-trending graphitic structure, and is hosted by the sandstone, at the unconformity, and in much lesser amounts in the underlying basement rocks. Petrographic observations aided by the use of RAMAN spectroscopy and SEM-EDS, have been used to create a paragenetic sequence of mineralization (Fig.1). Future work will focus on fluid inclusion studies using microthermometry, LA-ICP-MS, and mass spectrometry of contained gases. References:Allen, T., Quirt, D., Masset, O. (2017a). Midwest A Uranium Deposit, Midwest Property, Northern Mining District, Saskatchewan, NTS Map Area 741/8: 2017 Mineral Resource Technical Report. AREVA Resources Canada Inc. Internal Report No. 17-CND-33-01. Allen, T., Quirt, D., Masset, O. (2017b). Midwest Main Uranium Deposit, Midwest Property, Northern Mining District, Saskatchewan, NTS Map Area 741/8: 2017 Mineral Resource Technical Report. AREVA Resources Canada Inc. Internal Report No. 17-CND-33-01. Jefferson, C.W., Thomas, D.J., Gandhi, S.S., Ramaekers, P., Delaney, G., Brisbin, D., Cutts, C., Portella, P., and Olson, R.A., 2007: Unconformity-associated uranium deposits of the Athabasca Basin, Saskatchewan and Alberta. Geological Survey of Canada, Bulletin 588, p. 23–67.


1993 ◽  
Vol 30 (4) ◽  
pp. 653-673 ◽  
Author(s):  
P. Bruneton

The Cigar Lake uranium deposit occurs within the Athabasca Basin of northern Saskatchewan, Canada. Like other major uranium deposits of the basin, it is located at the unconformity separating Helikian sandstones of the Athabasca Group from Aphebian metasediments and plutonic rocks of the Wollaston Group. The Athabasca Group was deposited in an intra-continental sedimentary basin that was filled by fluviatile terrestrial quartz sandstones and conglomerates. The group appears undeformed and its actual maximum thickness is about 1500 m. On the eastern side of the basin, the detrital units correspond to the Manitou Falls Formations where most of the uranium deposits are located. The Lower Pelitic unit of the Wollaston Group, which lies directly on the Archean basement, is considered to be the most favourable horizon for uranium mineralization. During the Hudsonian orogeny (1800–1900 Ma), the group underwent polyphase deformation and upper amphibolite facies metamorphism. The Hudsonian orogeny was followed by a long period of erosion and weathering and the development of a paleoweathering profile.On the Waterbury Lake property, the Manitou Falls Formation is 250–500 m thick and corresponds to units MFd, MFc, and MFb. The conglomeratic MFb unit hosts the Cigar Lake deposit. However, the basal conglomerate is absent at the deposit, wedging out against an east–west, 20 m high, pre-Athabasca basement ridge, on top of which is located the orebody.Two major lithostructural domains are present in the metamorphic basement of the property: (1) a southern area composed mainly of pelitic metasediments (Wollaston Domain) and (2) a northern area with large lensoid granitic domes (Mudjatik Domain). The Cigar Lake east–west pelitic basin, which contains the deposit, is located in the transitional zone between the two domains. The metamorphic basement rocks in the basin consist mainly of graphitic metapelitic gneisses and calcsilicate gneisses, which are inferred to be part of the Lower Pelitic unit. Graphite- and pyrite-rich "augen gneisses," an unusual facies within the graphitic metapelitic gneisses, occur primarily below the Cigar Lake orebody.The mineralogy and geochemistry of the graphitic metapelitic gneisses suggest that they were originally shales. The abundance of magnesium in the intercalated carbonates layers indicates an evaporitic origin.The structural framework is dominated by large northeast–southwest lineaments and wide east–west mylonitic corridors. These mylonites, which contain the augen gneisses, are considered to be the most favourable features for the concentration of uranium mineralization.Despite the presence of the orebody, large areas of the Waterbury Lake property remain totally unexplored and open for new discoveries.


Author(s):  
Mohammad Ayub Khan

A handful of business schools in the world are famous in their respective countries of origin, but have also achieved global acclaim for their sustained and continued success as world-class academic institutions. This chapter describes some of these business schools and includes successful factors that have made them top quality institutions, such as general performance indicators used to rank and accredit business schools, common characteristics of success, as well as the role of ranking and accreditation as a source or force behind the fame and fortunes of such business schools. The chapter discusses the importance of national and international accreditation for the academic institutions and the pitfalls associated with accreditations. As examples of successful models, the chapter includes small success stories of business schools from emerging markets such as Pakistan and Mexico.


2018 ◽  
pp. 1143-1159 ◽  
Author(s):  
Mohammad Ayub Khan

A handful of business schools in the world are famous in their respective countries of origin, but have also achieved global acclaim for their sustained and continued success as world-class academic institutions. This chapter describes some of these business schools and includes successful factors that have made them top quality institutions, such as general performance indicators used to rank and accredit business schools, common characteristics of success, as well as the role of ranking and accreditation as a source or force behind the fame and fortunes of such business schools. The chapter discusses the importance of national and international accreditation for the academic institutions and the pitfalls associated with accreditations. As examples of successful models, the chapter includes small success stories of business schools from emerging markets such as Pakistan and Mexico.


2020 ◽  
Vol 211 ◽  
pp. 106464 ◽  
Author(s):  
Huan Kang ◽  
Yue-long Chen ◽  
Da-peng Li ◽  
Jun-xiang Zhao ◽  
Fu-rong Cui ◽  
...  

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