Quaternary geology, ice-flow history and till geochemistry of the Huckleberry Mine region, west-central British Columbia
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...
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Language: | English en |
Published: |
2008
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Online Access: | http://hdl.handle.net/1828/1260 |
Summary: | 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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