Browsing University of Alaska Fairbanks by Subject "Yukon"
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Geology and origins of the Mike Lake (Skarn Ridge) gold-copper skarn deposit, Yukon Territory, CanadaThe Mike Lake (Skarn Ridge) deposit has an elemental suite of Cu-Au-Bi-As-Sn and a mineralogy dominated by scapolite, clinopyroxene, and pyrrhotite, with lesser garnet and Fe-axinite (a Ca-borosilicate). This study is the first published description of the deposit. The deposit was studied with techniques including drill core logging and detailed surface mapping (1:5,000 scale), combined with petrographic examination of polished thin sections, X-ray fluorescence and X-ray diffraction analyses, electron microprobe analysis of major minerals, and ⁴⁰Ar/³⁹Ar dating. Ore mineralization styles include vein-controlled, disseminated, and net-textured replacements of clinopyroxene and calcite by electrum, chalcopyrite, pyrrhotite, and arsenopyrite, with variable native bismuth and bismuth tellurides. A strong Au:Bi correlation (R² = 0.74) indicates the two elements were transported and deposited together; however a poor Au:Cu correlation (R² = 0.23) suggests different mineralization events or different modes of Au-Cu transport. The virtual absence of retrograde alteration provides an ideal opportunity to examine metal- and silicate-zoning patterns apparently associated with prograde alteration. Using the ⁴⁰Ar/³⁹Ar dating method, I have determined that the adjacent Mike Lake pluton is younger than the skarn, and hence, genetically unrelated. Through analysis of samples from surface and 72 drill holes, I show systematic zoning in skarn mineralogy and mineral compositions suggesting deposit derivation from an unknown pluton to the southeast at depth.
Indigenous-crown relations in Canada and the Yukon: the Peel Watershed case, 2017The history of Indigenous-Crown relations in Canada has varied regionally and temporally. With the Constitution Act of 1982, however, Canada entered a new era. Section 35 of the Constitution recognized Indigenous treaty and land rights, and the Supreme Court of Canada has consistently interpreted this section liberally in favor of Canada's Indigenous Peoples. The Court has upheld the honour of the Crown in emphasizing the national and subnational governments' duty to consult diligently when engaging in development on the traditional territories of First Nations, Metis, and Inuit. The "citizens-plus" model of asserting and protecting Indigenous rights, first coined in the Hawthorn Report of 1966, has proved effective in these court cases, most recently in the Yukon's Peel Watershed case from 2014 to 2017. Yet, engaging with the state to pursue and to invoke treaty rights has forced socioeconomic and political changes among Yukon First Nations that some scholars have argued are harmful to the spiritual and physical wellbeing of Indigenous communities, mainly through alienation from their homelands. The Peel Watershed case demonstrates the unique historical development of Yukon First Nations rights and the costs and benefits of treaty negotiations and asserting Indigenous rights.
Permafrost geosystem assessment at the Beaver Creek Road experimental site (Alaska Highway, Yukon, Canada)An experimental site testing a range of engineering techniques for mitigating permafrost degradation along the Alaska Highway has been established in 2008 at Beaver Creek (Yukon, Canada). Based on the hypothesis that permafrost has a distinctive sensitivity to climate and terrain conditions at a local scale, a geosystem approach, which considers a set of components (e.g. permafrost, embankment, vegetation, hydrology and hydrogeology) and accounts for dynamics within a system, was applied to obtain a better understanding of local permafrost conditions and changes within the system. Therefore, this assessment, for ultimately measuring performance of the mitigation techniques, integrated the permafrost conditions, in terms of cryostratigraphic units and soil properties, with local climate, natural terrain and embankment conditions. The author, who participated in the site establishment, its baseline investigations and monitoring programs, presents here the baseline geosystem studies at the Beaver Creek Road Experimental Site with an emphasis on permafrost.