Implementation of kriging and geostatisticalsimulation methods to si̇vas gold deposits

In this study, Evliya Tepe (Sivas) gold (Au) and silver (Ag) reserves of gold deposits are estimated by kriging and grade model is constructed by geostatistical simulation method. To create a a database, previous geological and chemical analysis are compiled.As a result of Au and Ag data analyses, drilling data is brought to be ready for geostatistic analyze by converting into 4 m spaced composites. Wireframe is produced by drawing sections containing drilling logs and block model is defined within this system and no anisotropy is seen in both groups. Appropriateness and adequacy of the variogram models were tested by cross-validation. Au and Ag are estimated in the block model by Ordinary Kriging. Reserve and grade are calculated in certain range of cut-off grade. By comparing statistics and graphics of real and estimated data, predictions are confirmed. Grade model is created with Sequential Gauss Simulation (SGS) and local grade changes are examined. Accuracy of simulation models have been tested with reproduction of histogram, variogram and summary statistics. At the end of Ordinary Kriging and SGS application, geometric positions of ore distribution are represented by three and two dimensional graphics, sections and maps. By preparing standard deviation maps for SGS results, the uncertainties in the model are revealed.