120 Regolith 2005 – Ten Years of CRC LEME STATISTICAL METHODS FOR DETERMINING GEOCHEMICAL RESIDENCE IN MINERAL PHASES: EVALUATION OF PEDOGENIC CALCRETE TRACE ELEMENT DATA

SCIENTIFIC OBJECTIVE The development of selective or sequential extraction procedures for geochemical exploration programs requires intensive chemical experimentation with special attention to factors such as leaching time, temperature, grainsize and the type and concentration of leachate used in the extraction experiment. Considerable experimental error is also introduced during the chemical reaction through differences in the leachability of trace elements from different minerals as well as resorption onto suspended clay particles during the extraction procedure. The current study examines the use of statistics for determining the residence phases of trace elements utilising alternative methodologies using whole-rock geochemical data analysed from pedogenic calcrete and parent material sampled in profiles from South and Western Australia. The aims being to determine the geochemical changes that occur in the zone of calcium accumulation, i.e. does the minor and trace element composition of pedogenic calcrete reflect the detrital component (parent material residue or windblown aeolian input) such as quartz, clays and lithic fragments diluted only by carbonate; or are certain trace elements associated with calcium in the pedogenic calcrete profile? CHEMICAL AND STATISTICAL METHODS AND RESULTS Whole-rock elemental compositions of pedogenic calcrete sampled from profiles were determined b