A practical application of the geological and mining characterization method to the “Rosa Porriño” deposit (Galicia, Spain). Quality cartography and estimation of the distribution of reserves for mining exploitation planning

Abstract

This paper presents a study of the "Rosa Porriño" granite, which is known worldwide and has been marketed for more than 50 years, through the application of geologic-mining techniques. These techniques are widely used for analyzing rock masses with the aim of commercially exploiting them. The basis is the general criteria for the characterization of geological and mining parameters: the lithologies present and their distribution, types and location of fractures, the industrial quality of the rock and the location of the exploitable rock volumes, previous activity, planning possibilities and rationalization of the exploitation, to name a few. This geological and mining information was used to make a map of the industrial qualities, forming the basis for the estimation of reserves and their distribution within the deposit. The application of geostatistical techniques allowed the definition of the three dimensions and thus the existing volumes corresponding to each industrial quality (defined in the geological-mining cartography). Four different qualities were defined and their volumes estimated, namely first and second qualities for granite suitable for its use as ornamental stone or other applications of high added value; third quality for the granite suitable for its use as a construction material (generally of smaller volume than the previous qualities) and the fourth quality for the granite for aggregates. The overburden zones were determined as well. Once the reserves of the qualities and their spatial distribution within the deposit are known, different alternatives for a rational exploitation can be considered for the existing operating units. This modeling enables a more effective and efficient mining operation, with controlled, lower environmental impact and thus with a more sustainable exploitation of the mining resources.