The Touro volcanogenic massive sulfide (VMS) deposit is located in the NW of the Iberian Variscan massif in the Galicia-Trás-os-Montes Zone, an amalgamation of several allochthonous terrains. The Órdenes complex is the most extensive of the allochthone complexes, and amphibolites and paragneisses host the deposit, characterized as being massive or semimassive (stringers) sulfides, mostly made up of pyrrhotite and chalcopyrite. The total resources are 103 Mt, containing 0.41% copper. A 3D model of the different orebodies and host rocks was generated using data from 1090 drill core logs. The model revealed that the structure of the area is a N–S-trending antiform. The orebodies crop out in the limbs and in the hinge zone. The mineralized structures are mostly tabular, up to 100 m in thickness and subhorizontal. Based on the petrography, geochemistry and the 3D model, the Touro deposit is classified as a VMS of the mafic-siliciclastic type formed in an Ordovician back-arc setting, which was buried and metamorphosed in Middle Devonian.

Three-dimensional block models are the most frequently used tool for estimating mineral resources and reserves within a mineral deposit. In open pit mining, the basis of mine design and the long term mining schedule is calculation of the ultimate pit limit. The ultimate pit limit is the pit with the highest profit value. Over the years, different algorithms have been developed that enable us to calculate the final pit: floating or mobile cone, floating cone II and its corrected forms, floating cone III, the Korobov algorithm and its corrected form, the Lerchs–Grossmann 2D algorithm (dynamic programming), and the Lerchs–Grossmann 3D algorithm (graph theory). All these algorithms have advantages and disadvantages. The floating cone method stands out for its simplicity, speed, and easy implementation, even for calculating a pit with a variable slope angle. The main drawback of this method is that it is unable to examine all possible combinations. For this reason, the algorithm does not consistently give optimal results, which is why it has required improvements over time. However, the improved methods still have some problems. To overcome these problems, a new algorithm called the floating cone IV method will be demonstrated in this paper.

The presence of large palaeo-landslides can hinder the construction of railway lines if they cause an alteration of the natural balance of the slope, significantly increasing the cost of the project. During the construction works in a section of the Madrid–Asturias high-speed railway line (Spain), a large-scale hillside instability affected 460 m of the section. The ground movement began 10 months after the start of the excavations and remained active throughout the observation period (2008–2010). Data provided by fieldwork, boreholes and instrumental monitoring have allowed the investigation of the geological units involved, together with the geometry and the kinematics of the mass movement. This landslide involves a Paleozoic basement with an estimated volume of 4 400 000 m ³ . It shows low displacement rates (<45 mm a ⁻¹ ) and was accommodated on a single surface of rupture, which reaches more than 60 m depth. The kinematics is favoured by structural and lithological conditions, there being a strong rheological contrast in the lower part of the mobilized ground. This movement is linked to a large palaeo-landslide that was partially reactivated when excavations undermined the lower slopes of the hillside. Technical solutions for the stabilization have already caused an additional cost of 17% over the initial budget.