24 documents found, page 1 of 3
Contact metamorphism and dolomitization overprint on Cambrian carbonates from t...
Roseiro, José; Moreira, Noel; Andrade, Laura; Nogueira, Pedro; de Oliveira, Daniel Pipa Soares; Eguiluz, Luis; Mirao, Jose; Moita, PatríciaABSTRACT: he Cambrian Series 2 Carbonate Formation from the Alter do Chão Elvas-Cumbres Mayores unit (Ossa-Morena Zone, SW Iberian Massif) is composed of regionally metamorphosed marbles and marlstones that underwent chlorite zone metamorphism and preserve the primaeval limestone 87Sr/86Sr ratios (0.7083–0.7088). These are consistent with the established Lower Cambrian seawater curve, and therefore used for age...
Marble facades structural decay due to bowing – A comprehensive review
Pires, Vera; Lisci, Carla; Sitzia, Fabio; Lopes, Luis; Mirao, Jose; Dias, luis; neves, samuelNatural stone has been used in façades for centuries. Initially, stone elements were rather thick when used as construction elements, and the durability was appropriate. Scientific research on the properties of marble began in the late 19th century. In the following years, the thicknessof naturalfacadestonesdecreasedfromover1000mm(asinconstructionelements) to20-50mm (incladdingapplications)becauseofnewcuttingte...
Contact metamorphism and dolomitization overprint on Cambrian carbonates from t...
Roseiro, José; Moreira, Noel; Andrade, Laura; Nogueira, Pedro; de Oliveira, Daniel Pipa Soares; Eguiluz, Luis; Mirao, Jose; Moita, PatríciaABSTRACT: he Cambrian Series 2 Carbonate Formation from the Alter do Chão Elvas-Cumbres Mayores unit (Ossa-Morena Zone, SW Iberian Massif) is composed of regionally metamorphosed marbles and marlstones that underwent chlorite zone metamorphism and preserve the primaeval limestone 87Sr/86Sr ratios (0.7083–0.7088). These are consistent with the established Lower Cambrian seawater curve, and therefore used for age...
Um novo método de prospeção geoquímica para a identificação de depósitos profun...
Morais, Igor; Rosado, L.; Albardeiro, Luís; Mirao, Jose; Batista, Maria Joao; Matos, João XavierSUMMARY: The fast energetic transition in the world needs large amounts of mineral resources that are currently scarce. For the suppression of these needs, new mineral deposits must be found, demanding the development of new exploration techniques. Currently, in several metalogenetic provinces, surface deposits are rare. In the Iberian Pyrite Belt, geophysical techniques, namely gravimetry and electromagnetics,...
Limestones durability study on salt crystallisation: An integrated approach
Lisci, Carla; Pires, Vera; Sitzia, Fabio; Mirao, JoseLimestones are often used as building stones in contemporary architecture. Salt weathering is one of the main threats affecting this lithology. In this study, two Portuguese limestones (Branco Real and Lioz Coral) were subjected to laboratory salt crystallisation cycles by reconsidering the normative EN 12370 (Determination of the resistance to crystallisation of salts). The proposed test method consisted of 2 ...
ADVANCED TECHNOLOGIES FOR NATURAL STONE|INOVSTONE 4.0-IMPORTANT RESULTS FROM A ...
Pires, Vera; Mirao, Jose; Sitzia, Fabio; Lisci, Carla; Duarte, José; Dias, Luis; Alves, Tiago; Lopes, Luis; Martins, RubenThe natural stone as a building material has been revealed to have much lower life cycle costs than other materials as concrete, glass and steel. For this reason, it has a positive impact on the environment. However, several incidents with different pathologies on distinct lithologies has led to an increase in maintenance costs. The lack of knowledge on a stone performance over time and the frequent absence of ...
Um novo método de prospeção geoquímica para a identificação de depósitos profun...
Morais, Igor; Rosado, L.; Albardeiro, Luís; Mirao, Jose; Batista, Maria Joao; Matos, João XavierSUMMARY: The fast energetic transition in the world needs large amounts of mineral resources that are currently scarce. For the suppression of these needs, new mineral deposits must be found, demanding the development of new exploration techniques. Currently, in several metalogenetic provinces, surface deposits are rare. In the Iberian Pyrite Belt, geophysical techniques, namely gravimetry and electromagnetics,...
Building stones durability by UVA radiation, moisture and spray accelerated wea...
Lisci, Carla; Sitzia, Fabio; Pires, Vera; Mirao, JosePhotodegradation is the alteration of the materials due to exposure to sunlight. This phenomenon is evident in paint, ink, pharmaceuticals and polymers. In polymers, photodegradation is caused by ultraviolet radiation (300–400 nm), which activates the breaking of C-C bonds and the formation of hydroperoxides, thermolabile substances. Although to a lesser extent, photodegradation also affects more resistant mate...
Testing LA-ICP-MS analysis of archaeological bones with different diagenetic hi...
Maurer, Anne-France; Barrulas, Pedro; Person, Alain; Mirao, Jose; Barrocas Dias, Cristina; Boudouma, Omar; Segalen, LoicLA-ICP-MS is a powerful technique requiring minimal sample preparation and providing high spatial resolution which may offer the possibility of analysing trace elements in targeted pristine areas of archaeological bone sections. This would provide invaluable information about an individual's life if combined with the geochemical composition of the teeth from the same individual. However, there is no consensus r...
An experimental approach for smelting tin ores from Northwestern Iberia
Figueiredo, Elin; Lackinger, Aaron; Comendador Rey, Beatriz; Silva, Rui J.C.; Veiga, João P.; Mirao, JoseIn the present work microstructural and chemical analysis of tin and slag that resulted from three smelting experiments reconstructing prehistoric conditions are presented. Cassiterite ores were collected from northwestern (NW) Iberian deposits and were smelted in a small open pit. Results show that the loss in tin can be very high, up to 80%, mainly as a result of volatilization of Sn species. The experiments ...