Surficial geology along the Spokane River, Washington and its relationship to the metal content of sediments (Idaho-Washington stateline to Latah Creek confluence): Sediment geochemistry

The Spokane River flows westward into eastern Washington out of the
northern end of Lake Coeur d'Alene in northern Idaho. The river
and lake lie downstream of the Coeur d'Alene mining district, where
over 56 million metric tonnes of metal-enriched tailings were
disposed into the Coeur d'Alene River between 1886 and 1968 (Long, 1998).
Geochemical analyses of riverine sediments in the Spokane River
by the Washington Dept of Ecology (Johnson, 1999), the US Geological
Survey (Grosbois and others, 2001; Box and others, in prep.) and an EPA
contractor (URS Greiner, 2000, 2001) have indicated that Spokane River
sediments are variably enriched in metals derived from those tailings.
In this report we present a surficial geologic map (plates 1 through 8)
of the unconsolidated deposits within and along the Spokane River in
eastern Washington between the Idaho stateline and the confluence with
Latah Creek about 20 miles downstream. Existing sample datasets for
sediments and soils in and along the Spokane River are also located on
the map and the surficial geologic unit that was sampled is noted.
This work was undertaken in cooperation with the Washington Department
of Ecology and the Environmental Protection Agency.

斯波坎河（Spokane River）发源自爱达荷州北部的科达伦湖（Lake Coeur d'Alene）北端，向西流经华盛顿州东部。该河流与湖泊地处科达伦矿区（Coeur d'Alene mining district）下游，1886年至1968年间，共有超过5600万吨富含金属的尾矿被排入科达伦河（Coeur d'Alene River）（Long, 1998）。华盛顿州生态部（Washington Department of Ecology, Johnson, 1999）、美国地质调查局（US Geological Survey, Grosbois等, 2001；Box等, 待刊）以及美国环境保护署（Environmental Protection Agency, EPA）合同商URS Greiner（2000, 2001）对斯波坎河河相沉积物开展的地球化学分析显示，该河沉积物中不同程度富集了源自上述尾矿的金属元素。本报告编制了华盛顿州东部区域内，从爱达荷州界至下游约20英里处与拉塔溪（Latah Creek）汇流的河段内及沿岸斯波坎河流域松散沉积物的表层地质图（含1至8号图版）。本图同时收录了斯波坎河域内及沿岸现存的沉积物与土壤样品数据集，并标注了各采样点所属的表层地质单元。本研究由华盛顿州生态部与美国环境保护署合作开展。