عنوان مقاله [English]
Anomaly and lead-zinc index recognition of an area between Tappeh-Sorkh and Gushfil, in Irankouh Pb- Zn mine, near Isfahan, was investigated. Interpretation for 12 elements, using 804 soil samples, was conducted. After early activities for censored data correction and transforming data for preparing normal distribution, anomalies recognition and separation were done using classical statistics, fractal and EDA (Exploratory Data Analysis) methods. Plotted anomalies maps prepared by three methods, show good conformity. Therefore, further studies in the regions showed overlapping resulted anomalies by three methods. Also detailed exploration by using geophysical IP methods was proposed.
Irankouh mine is located in Irankouh Mountains, 25 km southwest of the Isfahan city. Four mining area, including Tappeh-Sorkh, Gushfil, Khane – Gorgi are distinguished and their ore reserve has been determined separately. The aim of this research was anomaly and lead-zinc index recognition in the area between Tappeh-Sorkh and Gushfil. In this research 804 soil samples were taken and analyzed for 35 elements, but for interpretation only 12 elements were used. Anomalies recognition and separation were conducted using classical statistics, fractal and EDA (Exploratory Data Analysis) methods.
Methodology and Approaches
In the first step censored values were corrected, then the normality test on corrected datasets accomplished and showed that Ca, Mg and S have normal distribution. Other elements, which did not show normal distribution, were normalized by Log – normal and 3-parameters log distribution methods. Based on the parameters obtained from classical statistics and standard formula the anomaly and the background values were separated, using area- concentration model of fractal method. Also separation of anomaly from background in EDA method, was done with boxplot. Then the anomaly maps of elements for 3 methods were plotted.
Results and Conclusions
Comparison of the maps prepared by three methods, showed a good conformity. Since fractal is a structural method, it is more reliable. Further studies in the regions showed overlapping resulted anomalies by three methods. Pb, Zn and Cd were expanded in North-west, center and South-east. For more confirmation, detailed exploration by using geophysical IP methods is suggested in this area.