301. Anomaly identification in soil geochemistry using multifractal interpolation: a case study using the distribution of Cu and Au in soils from the Tongling mining district, Yangtze metallogenic belt, Anhui province, China.
- Author
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Yuan Feng, Bai Xiaoyu, Jia Cai, Jowitt S.M., Li Xiaohui, Zhang Mingming, Zhou Taofa., Yuan Feng, Bai Xiaoyu, Jia Cai, Jowitt S.M., Li Xiaohui, Zhang Mingming, and Zhou Taofa.
- Abstract
Interpolation between existing data points is necessary to construct contours and surfaces to determine spatial variations and anomalies within soil geochemical datasets. Cu and Au concentrations in both topsoil and deep soil of the Tongling mining district were used to compare kriging and multifractal kriging interpolation methods. To separate anomalous samples from background concentrations, anomaly thresholds for Cu and Au concentrations were calculated using a scattergram of contoured elemental concentrations versus number of mineral deposits contained in each contour. The anomaly threshold for Cu was 56.23 mg/kg; a contour constructed for this value contains known Cu deposits while also indicating other potentially prospective areas. For Au the value was 2.22 micrograms/kg, which is considered less robust than the Cu value due to the smaller number of known Au deposits. The better results obtained using deep soil sampling and multifractal kriging interpolation indicate that they may be more effective tools for mineral exploration in areas where the topsoil may be contaminated by anthropogenic activities such as mature mining districts., Interpolation between existing data points is necessary to construct contours and surfaces to determine spatial variations and anomalies within soil geochemical datasets. Cu and Au concentrations in both topsoil and deep soil of the Tongling mining district were used to compare kriging and multifractal kriging interpolation methods. To separate anomalous samples from background concentrations, anomaly thresholds for Cu and Au concentrations were calculated using a scattergram of contoured elemental concentrations versus number of mineral deposits contained in each contour. The anomaly threshold for Cu was 56.23 mg/kg; a contour constructed for this value contains known Cu deposits while also indicating other potentially prospective areas. For Au the value was 2.22 micrograms/kg, which is considered less robust than the Cu value due to the smaller number of known Au deposits. The better results obtained using deep soil sampling and multifractal kriging interpolation indicate that they may be more effective tools for mineral exploration in areas where the topsoil may be contaminated by anthropogenic activities such as mature mining districts.