Compilation and synthesis of previously published geochemical data are an integral part of the surficial geology component of this Project. The preliminary maps below display abundances of four elements (significant in mineral exploration) in till from about 1500 locations. These samples were collected from 9.5 NTS map areas which have undergone surficial geology mapping by the GSC. For copper (Cu) and chromium (Cr), the clay-size (<0.002 mm) fraction of till was analyzed by ICP-AES methods for all samples except for the Hephburn Island map sheet where Atomic Absorption spectrometric analysis was used for element determination. The data used to create the maps illustrated below are available for download [XLS, 426.0 kb]. The complete data set will soon be released as a GSC open file.

The following maps display arsenic (As) and gold (Au) values for the silt+clay (<0.063 mm) fraction of till analyzed by INAA methods.

Background values for each element can be estimated based on regional distribution and underlying bedrock type, so that anomalous abundances can be readily detected. Readily apparent examples are: 1) Anomalous Au, As and Cr associated with mineralization in the Yellowknife area, 2) high Au contents in volcanic rocks of the central and north Slave; and 3) high Cu values related to gabbro sills south of Kugluktuk.