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Antunes I.M.H.R.,Polytechnic Institute of Castelo Branco | Gomes M.E.P.,University of Tras os Montes e Alto Douro | Neiva A.M.R.,GEOBIOTEC | Neiva A.M.R.,University of Coimbra | And 3 more authors.
Ecotoxicology and Environmental Safety

The mining complex of Murçós belongs to the Terras de Cavaleiros Geopark, located in Trás-os-Montes region, northeast Portugal. A stockwork of NW-SE-trending W>Sn quartz veins intruded Silurian metamorphic rocks and a Variscan biotite granite. The mineralized veins contain mainly quartz, cassiterite, wolframite, scheelite, arsenopyrite, pyrite, sphalerite, chalcopyrite, galena, rare pyrrhotite, stannite, native bismuth and also later bismuthinite, matildite, joseite, roosveltite, anglesite, scorodite, zavaritskite and covellite. The exploitation produced 335t of a concentrate with 70% of W and 150t of another concentrate with 70% of Sn between 1948 and 1976. The exploitation took place mainly in four open pit mines as well as underground. Three lakes were left in the area. Remediation processes of confination and control of tailings and rejected materials and phytoremediation with macrophytes from three lakes were carried out between 2005 and 2007. Stream sediments, soils and water samples were collected in 2008 and 2009, after the remediation process. Most stream sediments showed deficiency or minimum enrichment for metals. The sequential enrichment factor in stream sediments W>Bi>As>U>Cd>Sn=Ag>Cu>Sb>Pb>Be>Zn is mainly associated with the W>Sn mineralizations. Stream sediments receiving drainage of a mine dump were found to be significantly to extremely enriched with W, while stream sediments and soils were found to be contaminated with As. Two soil samples collected around mine dumps and an open pit lake were also found to be contaminated with U. The waters from the Murçós W>Sn mine area were acidic to neutral. After the remediation, the surface waters were contaminated with F−, Al, As, Mn and Ni and must not be used for human consumption, while open pit lake waters must also not be used for agriculture because of contamination with F−, Al, Mn and Ni. In most waters, the As occurred as As (III), which is toxic and is easily mobilized in the drainage system. The remediation promoted a decrease in metals and As concentrations of soils and waters, however the applied processes were not enough to rehabilitate the area. © 2016 Elsevier Inc. Source

Neiva A.M.R.,GEOBIOTEC | Neiva A.M.R.,University of Coimbra | Antunes I.M.H.R.,Polytechnic Institute of Castelo Branco | Carvalho P.C.S.,GEOBIOTEC | And 2 more authors.
Journal of Geochemical Exploration

The abandoned Mondego Sul uranium mine exploited quartz veins containing sulfides, torbernite, meta-uranocircite, saleeite, meta-saleeite and Fe-oxides and hydroxides and intersected the schist-greywacke complex. The exploitation was carried out in five open pits and produced 74,968kg U3O8 from 1987 to 1991. From July 2008 until now we observed that a lake had formed in one left open pit. Three dumps slightly covered by vegetation were located in steep slopes and streams and drainage water ran to a dam reservoir. Water, stream sediments and soils were contaminated in U and As. Uranium sulfate minerals were the most important contaminants of water, because U was positively correlated with SO4 2- in water. However, Fe-oxyhydroxides were the main retention minerals in soils, as U was positively correlated with Fe in soils. The Fe-Mn hydr(oxides) precipitate in streambeds retained a higher U concentration and a lower As concentration than stream sediments. Uranium and As were mainly retained in montmorillonite of stream sediments. Uranium concentration was up to 181μg/L in water, 266mg/kg in stream sediments and 377mg/kg in soils. The highest U concentration in water was reached at the beginning of spring, because the highest flow caused leaching of mineralized quartz veins, tailings and dumps and U from secondary minerals was released into water. The pH of water from the open pit was acidic and UO2 2+ was up to 50%, but drainage water from the largest dump was acidic to alkaline and had up to 88% UO2CO3. Arsenic concentration was up to 158μg/L in water, 211mg/kg in stream sediments and 223mg/kg in soils. The highest concentrations of most metals and As with significant As(III) in water occurred in summer due to evaporation. A restoration of the mining area is necessary to avoid a public hazard. © 2015 Elsevier B.V. Source

Sandu I.C.A.,University of Evora | Murta E.,Jose Figueiredo Laboratory | Eusebio F.,Diocesis of Viseu | Jorge L.,New University of Lisbon | And 5 more authors.
International Journal of Conservation Science

The paper presents an innovative interdisciplinary study focusing on the gilded/polychrome decoration emulating stone-like surfaces of a Rococo Retable from Saint Francis Church in Viseu, Portugal. This study was undertaken within a 3-year research project, abbreviated Gilt- Teller (http://www.gilt-teller.pt). For the characterization of the altarpiece's polychromy a representative number of samples were analyzed using a multi-technique methodology: Optical Microscopy coupled with fluorescent staining tests, microFTIR/FTIR and microRaman spectroscopy, micro-computerized tomography, Scanning Electron Microscopy coupled with energy dispersive X-ray spectrometry. Preliminary results reveal the stratigraphical and compositional characteristics of the polychromy: ground layers made of gypsum, anhydrite, calcium carbonate and animal glue; bole layers of red ochre color (Hematite); Au/Cu/Ag metal leaf, coated with shellac; marble-like polychromy made with blue, white and red pigments (Prussian blue, Lead white, Hematite, Vermillion) and "golden particles" (Cu-Zn alloy ink-type) applied in the form of fine lines on their shaft or on the round-shaped base of the columns. Source

Marinheiro J.,GEOBIOTEC | Mateus O.,GEOBIOTEC | Alaoui A.,Direction du Patrimoine Culturel | Amani F.,Institute National Des Science Of Larcheologie Et Du Patrimoine | And 2 more authors.
Comunicacoes Geologicas

The paleontological richness of Morocco has been scientifically known since at least the early 20th century. The region of the Middle Atlas, more specifically the Boulemane area, has been however only sparsely studied since the 1960s when it provided vertebrate fossils from the Middle Jurassic. In September 2013, a Moroccan-Portuguese expedition to the village of Taghrout, Boulemane, made excavations in a Pleistocene fossil site that once was a small high-altitude sedimentary basin, uncharted in previous geological maps. The excavations yielded bone material from large mammals, the most common findings are elephants ascribed to Elephas, but artiodactyls, turtles, and in-situ Acheulean tools were also collected. This represents a new and important paleontological and archeological site. In addition to the discoveries of Taghrout, the expedition also retrieved Quaternary vertebrate material from a nearby cave and found new Jurassic localities, with arcosaur bones and dinosaur footprints, in El Mers. © 2014 LNEG – Laboratório Nacional de Geologia e Energia IP. Source

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