The TREK surficial geochemistry project is developing a comprehensive and comparable geochemical dataset for the project area (Sacco et. al, 2014; Sacco and Jackaman, 2015). This objective is being supported by the reanalysis of till samples archived from previous regional geochemical surveys. Many of these projects were completed in the 1990s when sampling protocols were less strict and a considerable amount of the original results were generated using analytical methods that are now outdated. Reanalysis of these archived samples by modern laboratory techniques and genetic interpretations of the sample medium have significantly upgraded the till geochemical data set and the information is now directly comparable with new till data collected during the TREK project (Jackaman and Sacco, 2014).
A total of 1456 archive till samples plus quality control samples were analyzed for minor and trace elements by inductively coupled plasma--mass spectrometry (ICP-MS; 53 elements) following an aqua-regia digestion. A total of 873 archive till samples plus quality control samples were also analysed for major and minor elements by inductively coupled plasma--emission spectrometry (ICP-ES) following a lithium borate fusion and dilute acid digestion (11 major oxides, 13 elements and loss on ignition).