The biogeochemistry and pedogeochemistry of the West Hercules area, Rosebery, western Tasmania

摘要

Sixteen plant species were sampled over audknown pedogeochemical anomaly at West Hercules, Rosebery.udThis orientation survey was conducted to assess theudpotential of biogeochemical surveys in the West Coast-typeudrainforests. Three species were subsequentlyudre-sampled in order to determine the most sensitiveudplant organ for biogeochemical prospecting.udBoth a detailed pilot survey and an independentudtrial survey proved that young Nothofagus cunninghamiiudleaves accurately and precisely reflected the soil-leadudconcentrations. The primary plant-ash data canudbe enhanced with the use of selected elemental ratios.udA litter survey down five cut grid linesudshowed that plant-litter has great potential forudreflecting elemental concentrations in the soil.udThirty soil pits were dug and sampled everyudten centimetres, both on and off the pedogeochemicaludanomaly.udThe samples came from areas with potentialudcopper, lead and zinc mineralization and analyses haveudbeen restricted to these elements and potential scavengers.udChemical analyses for carbon, Cu, Pb, Zn, Ni, Fe andudMn revealed a distinct vertical and horizontaluddistribution that could be explained by changes in Eh/pHudenvironment and presence of "metal scavengers".udA sequential analysis of the soils indicatedudwhich elements were distributed over which soil phases.udCopper was sorbed in the clay while lead and zinc wereudoccluded in the iron and manganese oxides.