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- Contributo do acompanhamento das grandes obras de engenharia para a cartografia geológica : Caso de estudo do Corredor Internacional SulPublication . Morais, Igor; Albardeiro, Luís; Gonçalves, Pedro; Soares, S.; Solá, A. Rita; Dias, Ruben Pereira; Ressurreição, Ricardo; Castro-Pina, M.; Serra, B.; Pereira, Zélia; Mendes, MárciaSUMMARY: The follow up of new railway works, which will be part of the International South Corridor (Corredor Internacional Sul”, allowing the privileged access to new Ossa-Morena Zone outcrops, contributes to refine detailed geological mapping, as part of LNEG's mission. Along the different sections of the railway line, systematic geological sampling was carried out for petrographic, geochronological and paleontological studies. In addition, photographic record and three-dimensional modeling of the main slopes were performed using a drone. This methodology allows the construction of an information repository that can be consulted long after the works have been concluded and the outcrops become inaccessible. Besides the accuracy improvement of the geological contacts of the Ossa-Morena Zone rocks, the preliminary results confirmed the extent of Miocene debris flow sedimentation (conglomerates) and subsequent calcretization, and has identified new mineral occurrences.
- Geodiversidade no troço médio do rio Guadiana, argumentos para um futuro Geoparque no território de Mértola, Serpa, Moura e BarrancosPublication . Matos, João Xavier; Dias, Ruben Pereira; Pereira, Zélia; Ressurreição, Ricardo; Soares, S.; Mendes, Márcia; Albardeiro, Luís; Gonçalves, Pedro; Santos, Sara; Piçarra, José ManuelSUMMARY: The region of Mértola, Serpa, Moura and Barrancos, located in the middle section of the Guadiana River presents a distribution of geosites of great scientific value, constituting the argument to a future Geopark. The studied territory includes the Ossa-Morena (OMZ) and South Portuguese (SPZ) geological sequences, the tectonic boundary between these two variscan domains, the geomorphology conditioned by Alpine tectonics, the Guadiana, Ardila and Chança rivers incision and differential erosion of quartzites, dolomites and marbles. Significant geological heritage is also present in the SPZ Iberian Pyrite Belt VMS and OMZ copper deposits. The Guadiana territory presents a typical landscape and exceptional geosites in a natural habitat (e.g. Pulo do Lobo waterfalls). In total, 50 geosites were considered in 6 regions: Barrancos-Ardila, Ficalho, Serpa-Pias-Moura, Alcaria, Guadiana and São Domingos. The future project of Geopark will be planned by the four municipalities considering geoconservation plans and regional sustainable policy.
- Calcretos da região de Elvas : Estudo preliminarPublication . Soares, S.; Dias, Ruben Pereira; Ressurreição, Ricardo; Morais, Igor; Albardeiro, Luís; Gonçalves, Pedro; Solá, A. Rita; Castro-Pina, M.SUMMARY: The construction of a new railway in NE Alentejo crossing the Ossa Morena Zona allowed new detailed studies focused on the geological units and the structure of the area. In the Elvas region, the Miocene is represented by a coarse conglomerate covered by sandy mudstones. The conglomerate is coarser near the Messejana fault, where it is also tilted. Its deposition is probably related to the Alpine reactivation of the fault. The sediments and the basement rocks are strongly affected by Miocene calcretization. A chemical characterization of calcrete along vertical profiles was done with portable x-ray fluorescence equipment. The preliminary results show a decrease in CaO content upwards and an increase in SiO2.