COMBINING THE 3D GEOLOGICAL AND GEOSTATISTICAL MODELLING OF GYPSUM CONCENTRATION, USING HISTORICAL BOREHOLE AND BLASTHOLE INFORMATION

Geostatistics is used for estimating grade content in an ore deposit, thus enhancing the 3 Dimensional (3D) geological model precision, lowering the geological risk and boosting the performances of the mining industry. Despite the advantages, for decades the commercial application of the geostatistical tools has been mainly restricted to large metal mines. Except for a few notable cases, the majority of small-scale operations (quarries and industrial minerals) had hardly adopted geostatistical methods, due to the perceived complications compared to the advantages. Nowadays, things are changing, thanks to: the reduction of artisanal mining, the spread of informatization in all sectors, the necessity to improve the quarrying efficiency, the path towards sustainable mining and the challenges to obtain the social license to operate. This paper presents the recent digitalization and modelling work conducted at the “Monte Tondo” gypsum quarry (Italy), located in Northern Italy, besides the UNESCO natural heritage site named “karst and evaporite caves of the northern Apennines“. The geostatistical techniques were used to estimate the concentration block model using blastholes while a 3D geological model was realised using historical boreholes. Combining two models could help for a better understanding and interpreting of the extracted gypsum and could make an important improvement to detect the future areas of interventions, subjected to strict authorization rules by the local environmental authority.