A multidisciplinary approach to base metal exploration in an area of extreme anthropogenic distrubance: Mt Lofty Ranges, South Australia

[摘要] Executive SummaryLead isotope and geochemical data were used to rank the prospectivity of sulfidic soil-regolith samples collected as part of a regional geochemical survey by Skwarnecki and Fitzpatrick (2003).The sulfidic soil-regolith sample with the most anomalous Pb isotope and geochemical signature was collected from a saline-sulfidic wetland in Rodwell Creek.This area was selected for more focused base metal exploration.Soil-regolith samples were collected upstream and downstream from the identified anomalous sample site.Samples were collected from: (i) permanent sulfidic seeps and wetlands, (ii) seasonal sulfidic seeps and wetlands, (iii) stream channel sediments and (iv) stream overbank sediments.Soil morphology and geochemical analyses (including Pb isotopes) were used to distinguish characteristic signatures, which were produced by: (i) anthropogenic contamination (historic mining and smelting), (ii) zones of sulfide enrichment and (iii) country rock (background).These data were used to construct a predictive conceptual model, which helped explain the relationships between historical events at the Rodwell Creek study site (land clearance, mining and smelting [Pb/Z/Ag/Au/pyrite]) and the (i) morphology, (ii) geochemistry and (iii) Pb isotope composition of various sample media.The predictive conceptual model was used to separate anthropogenic geochemical signatures from those that were likely to have originated from unidentified, hidden zones of sulfide enrichment.Thus, a sub-section of the Rodwell Creek study site was identified as worthy of focussed mineral exploration.Geophysical prospecting (IP and resistivity surveys) was carried out and a disseminated zone of potential sulfide enrichment was identified.

[发布日期] 2010-11-03 [发布机构] CSIRO

[学科分类] 地球科学(综合)