Sharaf Abad-Hize Jan exploration area is one of the five anomalous zones in Arasbaran, east Azerbaijan province, 30Km NW Varzaghan, covering a total area of 15 Km2.
Mazra'eh Shadi mineralization occurred in southwestern part of the Sharaf Abad- Hize Jan study area on the scale of 1:5000, the estimation made based on the ore-body geometry. Modeling of the ore body made based on exploration operation data including 11 trenches, 13 boreholes and 394 chemical analyses.
Grade data pertain to definite locations of the boreholes. One of the problems with the data is the probability inequality of each sample space, i.e. sampling in a definite length or volume exploration excavations. Such data lead to errors in the estimation. Data were equivalenced in order to avoid such errors. The average of equivalenced gold concentration data is 2.75g/t, variance g2/t, standard deviation 6.05 g/t and population variation coefficient of 2.2. Analysis of raw and logarithmic frequency distribution diagrams and normalization index calculation indicates that data on raw and logarithmic concentration are not normal.
Variograms drawn are similar to each other in all directions; the average of the ore body directions does not suggest a definite direction, so the reserve is isotropic.
Mode variations and modeling optimized variogram, confirms that concentration data do not have a specific trend, so data lack spatial correlation.
Based on the studies, inverse squared distance distinguished suitable for evaluation of the reserve grade and tonnage, before which block model was accomplished.
In order to do this, first we should delineate the evaluation space. Then, involved parameters were determined i.e. radius of influence (of 999 m), minimum and maximum evaluation control point of 2 and 12 and distance weight of 2 for the estimation of the point.
Evaluation indicated that the reserve volume 296644 m3, blocks mean concentration of 3.92 gr/t of 3267 kg metal content.
At last, average grade and ore content of the block estimated based on the gold hypothetical cut-off grades of 0.1, 1 and 2 g/t. Cut-off grades increment from 0.1 to 1 g/t, increases the average grade 7% and decreases the tonnage 30%.
Radius of influence, block dimensions and the power of inverse squared distance in the evaluation were considered to determine critical parameter sensitivity, radius of influence proved one of the most critical factors affecting the evaluation.
The reserve tonnage was estimated up to 30, 40, 50 and 60 m. Average gold concentration of the blocks up to 30 m estimated 3.48 g/t with 252 kg metal content.