The Almadén mercury mining district.

The Almadén mining district includes the World?s largest mercury mine, exploited in a practically continuous way since Romans times until the closure of all the mines and metallurgic dependencies at the 1990?s and the 2000?s. In this work we summarize the most relevant information about the mining geology of the district, as well as the history of mercury and the Almadén mine. Final concerns include a compilation of the actions carried out to preserve the rich local mining heritage, funded and realized by different instances, such as the Almadén School of Mines (Escuela Universitaria Politécnica de Almadén, UCLM), the mining company (Minas de Almadén y Arrayanes S.A., MAYASA), and the regional government (Consejería de Educación y Cultura, Junta de Comunidades de Castilla la Mancha). All these action have implied a valorization of the heritage resources for tourism, as well as a preservation of the knowledge of the mining area history

Atlas Biogeoquímico de Castilla-La Mancha. Primeros resultados comparativos en los sinclinales de Guadalmez y Almadén (Ciudad Real)

Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

Creación y visualización de mapas prospectivos de mercurio mediante técnicas de inteligencia artificial

Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

Mercury-resistant rhizobial bacteria isolated from nodules of leguminous plants growing in high hg-contaminated soils.

A survey of symbiotic bacteria from legumes grown in high mercury-contaminated soils (Almadén, Spain) was performed to produce a collection of rhizobia which could be well adapted to the environmental conditions of this region and be used for restoration practices. Nineteen Hg-tolerant rhizobia were isolated from nodules of 11 legume species (of the genera Medicago, Trifolium, Vicia, Lupinus, Phaseolus, and Retama) and characterized. Based on their growth on Hg-supplemented media, the isolates were classified into three susceptibility groups. The minimum inhibitory concentrations (MICs) and the effective concentrations that produce 50% mortality identified the patterns of mercury tolerance and showed that 15 isolates were tolerant. The dynamics of cell growth during incubation with mercury showed that five isolates were unaffected by exposure to Hg concentrations under the MICs. Genetic analyses of the 16S rRNA gene assigned ten strains to Rhizobium leguminosarum, six to Ensifer medicae, two to Bradyrhizobium canariense, and one to Rhizobium radiobacter. Inoculation of host plants and analysis of the nodC genes revealed that most of them were symbiotically effective. Finally, three isolates were selected for bioremediation processes with restoration purposes on the basis of their levels of Hg tolerance, their response to high concentrations of this heavy metal, and their genetic affiliation and nodulation capacity

Consideraciones ambientales sobre el mercurio en el distrito minero de Almadén (Ciudad Real, España).

Los yacimientos de mercurio del Distrito minero de Almadén representan una singularidad mundial, al ser el único caso de un metal, el mercurio (Hg), que ha sido obtenido en una tercera parte de su producción mundial a partir de un solo yacimiento. El Distrito está formado por una serie de yacimientos de cinabrio (HgS), entre los que la mina de Almadén constituye el mayor de ellos. Los yacimientos se habrían formado como consecuencia de procesos geológicos actuando a lo largo del Paleozoico superior, pudiendo ser agrupados en dos tipos: los yacimientos de ?Tipo Almadén? y los yacimientos de ?Tipo Las Cuevas?. Los yacimientos habrían estado expuestos a la erosión atmosférica desde tiempo antes de la llegada de la actividad minera, lo que implica que tanto antes de esta actividad como evidentemente durante ésta se produciría la diseminación en el medio ambiente de los productos de este proceso, en forma de lixiviados naturales y antropogénicos, de partículas de polvo conteniendo el mineral, así como de vapor de mercurio emitido a la atmósfera desde suelos conteniendo el elemento, escombreras, labores mineras, instalaciones metalúrgicas, etc. Este trabajo presenta los diversos estudios llevados a cabo hasta la fecha sobre las implicaciones medioambientales y sobre la salud humana que se derivan de la presencia del metal disperso en el Distrito minero de Almadén (Ciudad Real)

Riesgos ambientales asociados a la gestión inadecuada de residuos mineros en una explotación minera de oro, Remance, Panamá

Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu

Evaluation of antimony availability in a mining context: Impact for the environment, and for mineral exploration and exploitation.

This work aims to establish Sb mobility, its transfer to biota and its effect on soil health in a semi-arid climate. The results show the presence of stibnite (Sb2S3) as the main primary Sb compound, bindhemite (Pb2Sb2O6(O,OH)), and minor proportions of stibiconite (Sb3+(Sb5+)2O6(OH)) as oxidised Sb species. This research also observes very high total Sb contents in mining materials (max: 20,000 mg kg−1) and soils (400–3000 mg kg−1), with physical dispersion around mining materials restricted to 450 m. The soil-to-plant transfer is very low, (bioaccumulation factor: 0.0002–0.1520). Most Sb remains in a residual fraction (99.9%), a very low fraction is bound to Fe and Mn oxy-hydroxides or organic matter, and a negligible proportion of Sb is leachable. The higher Sb mobility rates has been found under oxidising conditions with a long contact time between solids and water. The main factors that explain the poor Sb mobility and dispersion in the mining area are the low annual rainfall rates that slow down the Sb mobilisation process and the scarce formation of oxidised Sb compounds. All these data suggest poor Sb (III) formation and a low toxicological risk in the area associated with past mining activities. The low mobility of Sb suggests advantages for future sustainable mining of such ore deposits in a semi-arid climate and is also indicative of the limitations of geochemical exploration in the search for new Sb deposits

Heritage and the Sea: Maritime History and Archaeology of the Global Iberian World (15th -18th centuries)

This two-volume set highlights the importance of Iberian shipbuilding in the centuries of the so-called first globalization (15th to 18th), in confluence with an unprecedented extension of ocean navigation and seafaring and a greater demand for natural resources (especially timber), mostly oak (Quercus spp.) and Pine (Pinus spp.). The chapters are framed in a multidisciplinary and interdisciplinary line of research that integrates history, Geographic Information Sciences, underwater archaeology, dendrochronology and wood provenance techniques. This line of research was developed during the ForSEAdiscovery project, which had a great impact in the academic and scientific world and brought together experts from Europe and America. The volumes deliver a state-of-the-art review of the latest lines of research related to Iberian maritime history and archaeology and their developing interdisciplinary interaction with dendroarchaeology. This synthesis combines an analysis of historical sources, the systematic study of wreck-remains and material culture related to Iberian seafaring from the 15th to the 18th centuries, and the application of earth sciences, including dendrochronology. The set can be used as a manual or work guide for experts and students, and will also be an interesting read for non-experts interested in the subject.Volume 1 focuses on the history and archaeology of seafaring and shipbuilding in the Iberian early modern world, complemented by case studies on timber trade and supply for shipbuilding, analysis of shipbuilding treatises, and the application of Geographic Information Systems and Databases (GIS) to the study of shipwrecks.Volume 2 focuses on approaches to the study of shipwrecks including a synthesis of dendro-archaeological results, current interdisciplinary case studies and the specialist study of artillery and anchors.Peer reviewe

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

Geology and geochemistry of high-grade, volcanic rock-hosted, mercury mineralization in the nuevo entredicho deposit, Almadén district, Spain.

The Nuevo Entredicho deposit contains the richest concentration of mercury in the Almadén district, locally grading as much as 45% Hg. This ore deposit is hosted within an alkaline, conically shaped diatreme, about 150 m in diameter, which was subsequently filled with phreatomagmatic breccias. The diatreme cuts an Ordovician to Silurian clastic sedimentary rock sequence that is intercalated with basaltic sills. Structural analysis reveals a complex tectonic history with three main phases of Hercynian deformation. Mineralisation occurs as cinnabar replacements in volcanic tuffs and breccias and as recrystallised veins in tensions cracks associated with pyrophyllite and hydrothermal pyrite, which is strongly enriched in Cu, Pb and Hg. Lead isotopes in pyrite are characterised by high 207Pb/204Pb ratios (15.70-15.75), suggesting a contribution of ancient upper continental crust remobilised by Silurian-Devonian volcanism, with no mantle involvement. Sulphur isotopes of epigenetic cinnabar and pyrite range from +10.3 to +10.8‰ and from +10.6 to +11.9‰ respectively, suggesting a uniform sulphur source or a constant mixing ratio in the ore fluids. These isotopic compositions differ from those measured in the syngenetic deposits of the Almadén district; they suggest a higher temperature of ore formation of about 300 °C, and a genesis related to a distinct hydrothermal flow path at the Nuevo Entredicho deposit. Deposition of anomalously high-grade mercury ore at Nuevo Entredicho is related to a combination of (1) an abundance of black shale that provided sulphur and increasingly reducing conditions with high sulphide/sulphate ratios, (2) explosive Silurian-Devonian mafic magmatism that provided an initial source of mercury, (3) tectonic activity that lead to structurally favourable sites for ore deposition, and (4) replacement of secondary, carbonate-rich volcanic rocks