Examining paleoclimate-driven changes of elemental contaminants, such as Arsenic (As), increases the understanding of the mobility and fate of elements under a warming climate scenario. To characterize the variability in As sequestration in the sediments of a freshwater system in response to decadal- to centennial-scale climate oscillations, a freeze-core (CON01) was recovered from Control Lake, Northwest Territories. Radiocarbon dating of 13 bulk-organic samples provided temporal reference to core depth. Sediment geochemistry was determined using Itrax X-ray fluorescence core-scanning (Itrax-XRF). Elemental concentrations were measured on a sub-set of samples using ICP-MS after multi-acid (MA) digestion to assess the accuracy of Itrax-XRF results through a multivariate log-ratio (MLC) calibration. Comparison of Itrax-XRF to ICP-MS using the MLC in ItraXelerate software show Pearson's R² values >0.75, with the exception of As (R² = 0.44). MLC-calibrated Itrax-XRF elemental data were centered log-ratio (CLR) transformed to eliminate issues related to data closure. During the ca. 3300-yr sedimentary record, moderate-strength negative correlations between As_CLR and K_CLR (Spearman's ρ = −0.38, p-value < 0.001, n = 785), and As_CLR and Ti_CLR, (Spearman's ρ = −0.52, p-value < 0.001, n = 785) suggest that As is primarily sequestered in sediments during intervals of warmer temperatures and higher productivity. Proxies for sediment particle size (Ti_CLR, K_CLR) and As concentration (As_CLR) were examined for response to quasi-periodic climate oscillations using spectral analysis. Significant periodicities were observed with approximately 4–13, 30–60, 90–120, and 160–280 yr periods in Ti_CLR, K_CLR, and As_CLR records. These frequencies are interpreted as corresponding to the North Atlantic Oscillation and/or 8–14-yr Schwabe sunspot cycles, 30–60-yr Pacific Decadal Oscillation, and centennial-scale solar cycles (e.g., 90-yr Gleissberg cycle; 205-yr Suess cycle). Coeval occurrence of these periodicities revealed through wavelet analysis of Control Lake geochemistry data suggests that these climate cycles only impact Control Lake when they occur concurrently.

研究古气候驱动的元素污染物（例如砷）的变化，可以增加对气候变暖情况下元素的迁移率和命运的了解。为了表征淡水系统沉积物中As的固存变化，以响应年代际到百年尺度的气候振荡，从西北地区的Control Lake中回收了一个冰冻核心（CON01）。13个大有机样品的放射性碳测年为岩心深度提供了时间参考。使用Itrax X射线荧光岩心扫描（Itrax-XRF）确定了沉积物地球化学。多酸（MA）消化后，使用ICP-MS对子集中的样品进行元素浓度测量，以通过多元对数比（MLC）校准评估Itrax-XRF结果的准确性。^2个值> 0.75，但As（R ²  = 0.44）除外。对MLC校准的Itrax-XRF元素数据进行中心对数比（CLR）转换，以消除与数据关闭相关的问题。在ca。3300年沉积记录，As _CLR和K _CLR（Spearmanρ= −0.38，p值<  0.001，n =  785）和As _CLR和Ti _CLR之间（Spearmanρ= −0.52，p）中强度负相关-值<  0.001，n =  785）表明，在温度升高和生产率较高的时间间隔内，砷主要被隔离在沉积物中。沉积物粒度的代理（Ti _CLR，K使用光谱分析检查了_CLR和As浓度（As _CLR）对准周期性气候振荡的响应。在Ti _CLR，K _CLR和As _CLR记录中，观察到明显的周期，周期约为4-13、30-60、90-120和160-280年。这些频率被解释为对应于北大西洋涛动和/或8-14年的Schwabe太阳黑子周期，30-60年的太平洋年代际涛动和百年尺度的太阳周期（例如90年的Gleissberg周期； 205年的Suess周期）。通过对Control Lake地球化学数据进行小波分析揭示的这些周期的同时发生表明，这些气候周期仅在同时发生时才影响Control Lake。