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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Glacial Dispersal of Indicator Minerals from the Izok Lake Zn-Cu-Pb-Ag VMS Deposit, Nunavut, Canada

HICKEN, ANNA 01 February 2012 (has links)
Volcanogenic massive sulphide (VMS) deposits have a characteristic geochemical suite of enriched metals, mineralization and related hydrothermal alteration minerals; however, very little research has been carried out to determine which of these minerals may be useful for exploration in glaciated terrains and there are very few case studies in the public realm that document down-ice dispersal of these from known volcanogenic massive sulphide (VMS) deposits. In response to these needs and to refine and optimize surficial exploration methods in northern Canada, this study was conducted to examine the mineralogical signature of the Izok Lake Zn-Cu-Pb-Ag VMS deposit, Nunavut and its glacial till dispersal. Glacial sediments were deposited in the Izok Lake region by the Laurentide Ice Sheet. Detailed ice flow mapping indicates four stages of ice flow (oldest to youngest): 1) southwest (255 ̊); 2) weak flow to the northwest (315 ̊); a dominant ice flow and landform trend to the west-northwest (292 ̊), and 4) northwest (318 ̊) that was only observed east of the Iznogoudh Lake area (Hicken et al., 2011). The till geochemical signature (aqua regia digestion ICP-MS analysis) for the <0.063 mm fraction of the till matrix is defined by elevated (above the 95th percentile) contents of Zn, Cu, Pb, Fe, Ag, Cd, Bi, Hg, Se, In and Tl. These element signatures in till can be detected up to 8 km down-ice from the deposit. Till geochemical data is used to evaluate which till samples are metal-rich and may contain indicator minerals. Indicator minerals for the amphibolite metamorphic grade Izok Lake VMS deposit includes: gahnite, staurolite, axinite, chalcopyrite, sphalerite and pyrite. Sulphide minerals are present at lower abundances than gahnite and staurolite as they are not physically and chemically as robust/resistant during postglacial weathering. Gahnite is the most useful VMS indicator mineral in the postglaciated Izok Lake area, as it was readily identified in till heavy mineral concentrates, it is abundant (100 of grains), its chemically stable in the surficial weathering environment, and can be detected up to 40 km down-ice. This study is one of the first to document indicator minerals down-ice from a VMS deposit in a postglaciated terrain. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2012-01-31 18:24:19.909
2

Quaternary geology, ice-flow history and till geochemistry of the Huckleberry Mine region, west-central British Columbia

Ferbey, Travis 19 November 2008 (has links)
The Huckleberry Mine region experienced a complex ice-flow history during the Late Wisconsinan Fraser Glaciation. Cross-cutting and superimposition relationships observed in the field, constrain the relative timing of ice-flow events and indicate that a westerly-directed ice-flow event was followed by a smaller magnitude east to northeast event. This ice-flow reversal can be explained by the existence of an ice divide in the central interior of British Columbia during the Fraser Glaciation maximum. Although ice thickness exceeded relief in the region during the glacial maximum, and glaciers flowed west, up-valley towards the Coast Mountains, locally, ice-flow direction appears to still have been influenced by topography. Basal tills dominate the local Quaternary stratigraphy. These grey, overconsolidated, clayey-silt diamictons typically overlie Early Jurassic Telkwa Formation andesites, but they can also locally overlie advance-phase glaciofluvial sands and gravels. In the vicinity of the Main and East Zone areas, it is common to find visible pyrite and chalcopyrite grains (up to 3 mm in size), and mineralized clasts (pyrite +/- chalcopyrite) in the till matrix. At a 19 m vertical exposure, multiple till units were identified. These basal tills are distinguished primarily by changes in colour, matrix texture, and gravel content. Stratigraphic, sedimentological, lithological, and geochemical data from this exposure provide evidence of an ice-flow reversal in the Huckleberry Mine region during the Fraser Glaciation maximum. Till geochemical data define the locations of known sources of copper mineralization in the Huckleberry Mine region. Maximum, minimum, and median copper values in near-surface basal till samples are 8924 ppm, 29 ppm, and 216 ppm, respectively (n=106), while those for sub-surface basal till samples are 4167 ppm, 18 ppm, and 187, respectively (n=230). Locally developed dispersal trains indicate that mineralization from these sources has been transported towards the east and west. These dispersal trains are detectable in both near-surface and sub-surface basal till samples and also provide further evidence of an ice-flow reversal in the Huckleberry Mine region. Two westward-directed dispersal trains, that are isolated or disconnected from dispersal of the Main Zone area, suggest and that there could be undiscovered bedrock mineralization on Huckleberry Mine property.

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