The paleolimnological record of diatoms and climate, spanning the last 2800 years, was investigated in a small subarctic lake (Pocket Lake) that from AD 1948 to 2004 was contaminated by gold smelting waste. An age-depth model was constructed using a combination of ²¹⁰Pb, ¹⁴C, and tephra to determine a 2800 year history of lake ontogeny (natural aging), biological diversity, and regional climate variability. Diatoms form six strong paleoecological assemblages over time in response to changes in local hydrological and sedimentological conditions (including metals). Selected environmental variables explained 28.8% of the variance in the diatom assemblages, with Fe, Ca, and sediment end member distribution being important indicators. The diatom assemblages correlated to the Iron Age Cold Epoch (2800–2300 cal BP), Roman Warm Period (2250–1610 cal BP), Dark Age Cold Period (1500–1050 cal BP), Medieval Climate Anomaly (ca. 1100–800 cal BP), and the Little Ice Age (800–200 cal BP). The disappearance of Staurosira venter highlights the change from the Iron Age Cold Epoch to the Roman Warm Period. After deposition of the White River Ash (833–850 CE; 1117–1100 cal BP), transition to circumneutral conditions was followed in tandem by a transition to planktic influenced communities. Ten discrete peaks of Cu, Pb, and Zn were observed and attributed to soluble mobility from catchment soils through enhanced seepage and spring snowmelt. The prominent metal spikes were aligned with increases in Brachysira neoexilis. Downward mobilization of arsenic and antimony from contaminated surficial sediments highlight the problem of post depositional industrial contamination of paleosediments. Results demonstrate that paleoclimatic changes in the region, modulated by solar radiation, impacted temperature and precipitation in the lake catchment, influencing temporal shifts in diatom ecology. Changes in diatom taxa richness provided valuable information on the relative influence of water quality (planktic taxa) and sediment input (benthic taxa). The diatom assemblage succession also provides evidence that natural aging over time has played a role in the ecological evolution of the lake.

在一个小型的亚北极湖（Pocket湖）中调查了过去2800年中硅藻和气候的古泌尿科记录，该湖在1948年至2004年间受到金冶炼废物的污染。使用²¹⁰ Pb，¹⁴的组合构建了年龄深度模型C和Tephra确定2800年的湖泊个体发育（自然衰老），生物多样性和区域气候多变性的历史。随着时间的流逝，硅藻会形成六个强古生态组合，以响应当地水文和沉积条件（包括金属）的变化。选定的环境变量解释了硅藻组合中28.8％的方差，其中Fe，Ca和沉积物末端成员的分布是重要的指标。硅藻组合与铁器时代冷纪（2800–2300 cal BP），罗马暖期（2250–1610 cal BP），黑暗时代冷期（1500–1050 cal BP），中世纪气候异常（约1100–800）有关。 cal BP）和小冰河时代（800-200 cal BP）。Staurosira venter的消失着重介绍了从铁器时代的寒冷时代到罗马温暖时期的变化。在白河灰沉积（公元833–850； 1117–1100 cal BP）之后，过渡到周围环境，随后又过渡到受板状影响的社区。观察到了十个离散的Cu，Pb和Zn峰，这归因于流域土壤通过增强的渗流和春季融雪而产生的可溶性迁移。突出的金属尖峰与Brachysira neoexilis的增加对齐。从受污染的表层沉积物中向下迁移砷和锑突出了沉积后工业沉积对古沉积物的污染问题。结果表明，该地区的古气候变化受到太阳辐射的调节，影响了流域的温度和降水，影响了硅藻生态的时间变化。硅藻类群丰富度的变化为水质（浮游类群）和沉积物输入（底栖生物群）的相对影响提供了有价值的信息。硅藻的组合演替也提供了证据，表明随着时间的推移自然老化在湖泊的生态演变中发挥了作用。