Geochemical analysis of soils and sediments, Coeur d'Alene drainage basin, Idaho: sampling, analytical methods, and results

Abstract

This report presents the results of over 1100 geochemical analyses of samples of soil and sediment from the Coeur d'Alene (CdA) drainage basin in northern Idaho. The location (in 3 dimensions) and a lithological description of each sample is included with the laboratory analytical data. Methods of sample location, collection, preparation, digestion and geochemical analysis are described. Five different laboratories contributed geochemical data for this report and the quality control procedures used by each laboratory are described. Comparison of the analytical accuracy and precision of each laboratory is given by comparing analyses of standard reference materials and of splits of CdA samples. These geochemical data are presented in seven MS Excel tables and seven dBase4 tables. The seven dBase4 files allow users to more easily import these geochemical data into a GIS. Only one of these seven tables includes geospatial data AppendixB. However, in AppendixB there is a Site ID column that will allow users to link or join the matching Site Id columns in the six associated lithologic and geochemical tables. Due to format constraints of dBase4, the column names (headers) had to be modified to a maximum of only ten ASCII characters. As a result, some of the dBase4 column header names can be rather cryptic. To assist dBase files users, this ten digit dBase4 column name is also found directly under the more descriptive column names found in the MS Excel tables packaged with this report. Additional formatting requirements such as changing the “below detection limit” symbol (<) to a negative symbol (-) were used to accurately display the data the dBase4 format.