Decision criteria for the exploration of ornamental-stone deposits: Application to the marbles of the Portuguese Estremoz Anticline

Ornamental stones are almost ready-made raw materials with a high economic value for the building-construction industry. The discovery of new near-surface deposits, the very low exploitation efficiency, the huge amounts of wastes produced, and the land-use accessibility conditions are the main challenges that the extractive industry for this mineral resource is facing nowadays. Research on advanced geological exploration tools and methodologies is needed to reply to those challenges.During the process of geological ornamental-stone deposits exploration, the unique and decisive criteria that should be considered are its dimensions, homogeneity, and fracturing state. Lithostructural geological mapping and in situ fracturing surveys are the basic indispensable tools for their field assessment. By applying these criteria and tools to a marble-rich area in the Portuguese Estremoz Anticline and a step-by-step numerical evaluation of the qualitative geological parameters, the delimitation of the best target areas for exploitation or environmental rehabilitation has been effectively mapped.