The 4 August 2014 failure of Mount Polley mine tailings dam in central British Columbia, Canada, is the worst environmental disaster in British Columbia history. Around 25 million m³ of water, tailings solids and dam construction materials travelled as a slurry flow down nearby Hazeltine Creek. About 18.6 million m³ of tailings and displaced coarse sediment entered into the narrow, deep, fjord-like Quesnel Lake. Multibeam echosounding, sub-bottom profiling, sediment cores and theoretical models are used to examine erosion and deposition on the Hazeltine Creek fan-delta and the bed of Quesnel Lake by subaqueous sediment density flows generated from the slurry. Strong to very strong subaqueous debris flows eroded two deep subaqueous channels on the fan-delta in a period of less than 12 h. A model for subaerial debris-flow erosion overestimates submerged delta-front erosion rates in the channels because of evolution of the subaqueous debris flows and incomplete liquefaction of the eroding bed. The debris flows deposited a localized debrite with a hummocky surface composed of fine tailings and coarse displaced fan-delta and fluvial sediment. A flat, featureless, surface composed of fine-grained sediment adjacent to the debrite is interpreted as debrite/turbidite resulting from debris flows proximally and turbidity currents distally. Copper concentrations in cores are highly elevated compared to background concentrations in pre-event native lacustrine sediment. Deposits from subaqueous sediment flows generated by earthquakes and glacial lake outburst floods are generally thinner than those in Quesnel Lake caused by the tailings dam failure.

中文翻译：

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高强度水下泥石流和浊流的侵蚀、沉积和污染：从不列颠哥伦比亚省 Quesnel 湖附近尾矿坝的故障中获得的见解

2014 年 8 月 4 日，加拿大不列颠哥伦比亚省中部的 Mount Polley 尾矿坝发生故障，这是不列颠哥伦比亚省历史上最严重的环境灾难。围绕25000000米³行进作为浆料的水，尾矿固体和坝建筑材料流下附近哈泽泰小河。约1860万米³尾矿和移位的粗沉积物进入狭窄、深邃、峡湾般的克内尔湖。多波束回波、海底剖面、沉积物核心和理论模型用于检查由泥浆产生的水下沉积物密度流对 Hazeltine Creek 扇三角洲和 Quesnel 湖床的侵蚀和沉积。强到极强的水下碎屑流在不到 12 小时的时间内侵蚀了扇三角洲的两条深水下通道。由于水下泥石流的演化和侵蚀床的不完全液化，水下泥石流侵蚀模型高估了河道中淹没的三角洲前缘侵蚀率。泥石流沉积了局部碎屑，其表面呈丘状，由细尾矿和粗排错的扇三角洲和河流沉积物组成。一个扁平的，毫无特色的，由与碎屑岩相邻的细粒沉积物组成的表面被解释为由近端泥石流和远端浊流产生的碎屑岩/浊积岩。与事件发生前天然湖泊沉积物中的背景浓度相比，岩心中的铜浓度高度升高。地震和冰川湖溃决洪水产生的水下沉积物流的沉积物通常比尾矿坝溃决造成的克内尔湖中的沉积物薄。