Lateral Deposition and Geochemical Evolution of Mining- Related Metals in Floodplain Sediments

帕夫洛夫斯基这项研究项目将调查决定泛滥平原金属污染物沉积空间变异性的地球化学和地貌过程。研究区域是上密西西比河流域锌铅矿区(威斯康星州)的蓝河分水岭。该研究区域具有相对简单的自然景观和金属污染集中时期(1900-1920)的研究优势。研究设计要求从5个横断面、4个点沙洲和根据地貌标准战略性选择的几个活跃河道位置采集1310个样本。将绘制泛滥平原沉积的地层学和地球化学图，并确定沉积物-金属组合。结果将用于校准污染物扩散的分水岭尺度模型，并确定具有最大毒性影响或再动员潜力的特定泛滥平原位置。这项研究承诺在两个方面取得进展：更清楚地了解沉积物停留时间和滩涂污染物的现场化学变化；以及更好地预测金属污染物从点源向近岸和远岸滩涂汇的扩散。这项纵向和横向相结合的研究解决了我们在了解流域有毒金属储存和再动员方面的根本差距，它应该为未来的环境管理提供重要的信息。

Pavlowsky This research project will investigate the geochemical and geomorphic processes that determine the spatial variability of the sedimentation of metal contaminants in a floodplain. The study area is the Blue River watershed of the Upper Mississippi valley zinc and led mining district (Wisconsin). The study area affords the research benefits of a relatively simple physical landscape and a concentrated period of metal contamination (1900-1920). The research design calls for 1,310 samples to be taken from 5 cross-sections, 4 point bars, and several active-channel locations selected strategically according to geomorphological criteria. The stratigraphy and geochemistry of the floodplain deposits will be mapped, and the sediment-metal associations will be identified. The results will be used to calibrate watershed-scale models of contaminant dispersal and to identify specific floodplain locations that have the highest potential for toxic effects or remobilization. The research promises advances in two dimensions: a clearer understanding of sediment residence time and in situ chemical alterations to floodplain contaminants; and better predictions of the dispersal of metal contaminants from point sources to both proximal and distal floodplain sinks. The combined longitudinal-lateral study addresses fundamental gaps in our understanding of toxic metal storage and remobilization in watersheds, and it should provide information important for future environmental management.