As and S speciation in a submarine sulfide mine tailings deposit and its environmental significance: The study case of Portmán Bay (SE Spain)

The dumping of an estimated amount of 57 million tons of hazardous sulfide mine waste from 1957 to 1990 into Portmán's Bay (SE Spain) caused one of the most severe cases of persistent anthropogenic impact in Europe's costal and marine environments. The resulting mine tailings deposit completely infilled Portmán's Bay and extended seawards on the continental shelf, bearing high levels of metals and As. The present work, where Synchrotron XAS, XRF core scanner and other data are combined, reveals the simultaneous presence of arsenopyrite (FeAsS), scorodite (FeAsO₄·2H₂O), orpiment (As2S3) and realgar (AsS) in the submarine extension of the mine tailings deposit. In addition to arsenopyrite weathering and scorodite formation, the, the presence of realgar and orpiment is discussed, considering both potential sourcing from the exploited ores and in situ precipitation from a combination of inorganic and biologically mediated geochemical processes. Whereas the formation of scorodite relates to the oxidation of arsenopyrite, we hypothesize that the presence of orpiment and realgar is associated to scorodite dissolution and subsequent precipitation of these two minerals within the mine tailings deposit under moderately reducing conditions. The occurrence of organic debris and reduced organic sulfur compounds evidences the activity of sulfate-reducing bacteria (SRB) and provides a plausible explanation to the reactions leading to the formation of authigenic realgar and orpiment. The precipitation of these two minerals in the mine tailings, according to our hypothesis, has important consequences for As mobility since this process would reduce the release of As into the surrounding environment. Our work provides for the first time valuable hints on As speciation in a massive submarine sulfide mine tailings deposit, which is highly relevant for similar situations worldwide

TAO Conceptual Design Report: A Precision Measurement of the Reactor Antineutrino Spectrum with Sub-percent Energy Resolution

The Taishan Antineutrino Observatory (TAO, also known as JUNO-TAO) is a satellite experiment of the Jiangmen Underground Neutrino Observatory (JUNO). A ton-level liquid scintillator detector will be placed at about 30 m from a core of the Taishan Nuclear Power Plant. The reactor antineutrino spectrum will be measured with sub-percent energy resolution, to provide a reference spectrum for future reactor neutrino experiments, and to provide a benchmark measurement to test nuclear databases. A spherical acrylic vessel containing 2.8 ton gadolinium-doped liquid scintillator will be viewed by 10 m^2 Silicon Photomultipliers (SiPMs) of >50% photon detection efficiency with almost full coverage. The photoelectron yield is about 4500 per MeV, an order higher than any existing large-scale liquid scintillator detectors. The detector operates at -50 degree C to lower the dark noise of SiPMs to an acceptable level. The detector will measure about 2000 reactor antineutrinos per day, and is designed to be well shielded from cosmogenic backgrounds and ambient radioactivities to have about 10% background-to-signal ratio. The experiment is expected to start operation in 2022

Potential of Core-Collapse Supernova Neutrino Detection at JUNO

JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve

Detection of the Diffuse Supernova Neutrino Background with JUNO

As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO

Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30$M_{\odot}$ for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

Southwestern Africa on the burner: pleistocene carbonatite volcanism linked to deep mantle upwelling in Angola

The origin of intraplate carbonatitic to alkaline volcanism in Africa is controversial. A tectonic control, i.e., decompression melting associated with far-field stress, is suggested by correlation with lithospheric sutures, repeated magmatic cycles in the same areas over several million years, synchronicity across the plate, and lack of clear age progression patterns. Conversely, a dominant role for mantle convection is supported by the coincidence of Cenozoic volcanism with regions of lithospheric uplift, positive free-air gravity anomalies, and slow seismic velocities. To improve constraints on the genesis of African volcanism, here we report the first radiometric and isotopic results for the Catanda complex, which hosts the only extrusive carbonatites in Angola. Apatite (U-Th-Sm)/He and phlogopite 40Ar/39Ar ages of Catanda aillikite lavas indicate eruption at ca. 500–800 ka, more than 100 m.y. after emplacement of abundant kimberlites and carbonatites in this region. The lavas share similar high-μ (HIMU)–like Sr-Nd-Pb-Hf isotope compositions with other young mantle-derived volcanics from Africa (e.g., Northern Kenya Rift; Cameroon Line). The position of the Catanda complex in the Lucapa corridor, a long-lived extensional structure, suggests a possible tectonic control for the volcanism. The complex is also located on the Bié Dome, a broad region of fast Pleistocene uplift attributed to mantle upwelling. Seismic tomography models indicate convection of deep hot material beneath regions of active volcanism in Africa, including a large area encompassing Angola and northern Namibia. This is strong evidence that intraplate late Cenozoic volcanism, including the Catanda complex, resulted from the interplay between mantle convection and preexisting lithospheric heterogeneities

Conservació i condicionament de la vitrina de les sals del Museu Martorell (Museu de Ciències Naturals de Barcelona): 1921-2018

La vitrina de les sals de Cardona és un mobiliari dissenyat i construït el 1921 per Francesc Pardillo. Localitzada a l’edifici del Museu Martorell (Museu de Ciències Naturals de Barcelona), exposa i preserva una col·lecció d’exemplars de roques salines procedents de la Muntanya de Sal de Cardona i que van ser donades a finals del segle XIX per la Sra. Casilda de Salabert i Arteaga (Duquessa de Medinaceli) i el Sr. Miguel De Elías Marchal. El conjunt expositiu presenta un valor patrimonial molt significatiu. Degut al pas del temps i a la falta d’actuacions, la vitrina va deixar de conservar en òptimes condicions els exemplars i aquests van començar a alterar-se a l’interactuar amb la humitat ambiental, produint també una degradació generalitzada del mobiliari. Per tal de pal·liar aquesta degradació, s’ha dut a terme una restauració integral tant del mobiliari com dels exemplars, respectant al màxim el disseny original, realitzant les mínimes intervencions sobre les roques i dissenyant un sistema de control ambiental passiu i sostenible per tal de mantenir les condicions òptimes d’humitat relativa. Aquesta actuació ha frenat la degradació del conjunt expositiu i garanteix la seva conservació futura. Paraules clau: mineralogia, conservació, restauració, sal, Cardona, Catalunya.The Cardona salts showcase was built and designed in 1921 by Francesc Pardillo. Located at the Museu Martorell building (Museu de Ciències Naturals de Barcelona) it exposes and preserves a collection of salt rocks from the Cardona Salt Mountain. These specimens were donated at the end of 19th century by Ms. Casilda de Salabert i Arteaga (Medinaceli Duchess) and Mr. Miguel De Elías Marchal and represent a collection with a significant heritage and historic value. Due to the trace of time and the lack of conditioning interventions, this showcase did not preserve the samples in optimal conditions. The specimens began an alteration process interacting with high relative humidity, also generating the general degradation of the showcase furniture. In order to stop this degradation, it has been carried out an integral conditioning of this showcase but also of the salt specimens. This process has been executed respecting the original design of the showcase and carrying out the minimum intervention into the rock samples. In addition, a new passive and sustainable system to control environmental conditions has been set up to maintain optimal humidity conditions. This action stopped the degradation of the showcase as well as the specimens and guarantees their preservation over time. Keywords: mineralogy, conservation, conditioning, salt, Cardona, Catalonia.La vitrina de las sales de Cardona es un mobiliario diseñado y construido en 1921 por Francesc Pardillo. Localizada en el edificio del Museo Martorell (Museo de Ciencias Naturales de Barcelona), expone y conserva una colección de ejemplares de rocas salinas procedentes de la montaña de sal de Cardona que fueron donadas a finales del siglo XIX por la Sra. Casilda de Salabert i Arteaga (Duquesa de Medinaceli) i el Sr. Miguel de Elías Marchal. El conjunto expositivo presenta un valor patrimonial muy significativo. Debido al paso del tiempo y a la falta de actuaciones, la vitrina dejó de conservar en óptimas condiciones los ejemplares y estos empezaron a alterarse al interactuar con la humedad ambiental, produciendo también una degradación generalizada del mobiliario. Para paliar dicha degradación, se ha llevado a cabo una restauración integral tanto del mobiliario como de los ejemplares, repetando al máximo el diseño original, realizando las mínimas intervenciones sobre las rocas y diseñando un sistema de control ambiental pasivo y sostenible para matener las condiciones óptimas de humedad relativa. Esta actuación ha frenado la degradación del conjunto expositivo y garantiza su conservación futura. Palabras clave: mineralogía, conservación, restauración, sales, Cardona, Cataluñ

Conservació i condicionament de la vitrina de les sals del Museu Martorell (Museu de Ciències Naturals de Barcelona): 1921-2018

La vitrina de les sals de Cardona és un mobiliari dissenyat i construït el 1921 per Francesc Pardillo. Localitzada a l’edifici del Museu Martorell (Museu de Ciències Naturals de Barcelona), exposa i preserva una col·lecció d’exemplars de roques salines procedents de la Muntanya de Sal de Cardona i que van ser donades a finals del segle XIX per la Sra. Casilda de Salabert i Arteaga (Duquessa de Medinaceli) i el Sr. Miguel De Elías Marchal. El conjunt expositiu presenta un valor patrimonial molt significatiu. Degut al pas del temps i a la falta d’actuacions, la vitrina va deixar de conservar en òptimes condicions els exemplars i aquests van començar a alterar-se a l’interactuar amb la humitat ambiental, produint també una degradació generalitzada del mobiliari. Per tal de pal·liar aquesta degradació, s’ha dut a terme una restauració integral tant del mobiliari com dels exemplars, respectant al màxim el disseny original, realitzant les mínimes intervencions sobre les roques i dissenyant un sistema de control ambiental passiu i sostenible per tal de mantenir les condicions òptimes d’humitat relativa. Aquesta actuació ha frenat la degradació del conjunt expositiu i garanteix la seva conservació futura. Paraules clau: mineralogia, conservació, restauració, sal, Cardona, Catalunya.The Cardona salts showcase was built and designed in 1921 by Francesc Pardillo. Located at the Museu Martorell building (Museu de Ciències Naturals de Barcelona) it exposes and preserves a collection of salt rocks from the Cardona Salt Mountain. These specimens were donated at the end of 19th century by Ms. Casilda de Salabert i Arteaga (Medinaceli Duchess) and Mr. Miguel De Elías Marchal and represent a collection with a significant heritage and historic value. Due to the trace of time and the lack of conditioning interventions, this showcase did not preserve the samples in optimal conditions. The specimens began an alteration process interacting with high relative humidity, also generating the general degradation of the showcase furniture. In order to stop this degradation, it has been carried out an integral conditioning of this showcase but also of the salt specimens. This process has been executed respecting the original design of the showcase and carrying out the minimum intervention into the rock samples. In addition, a new passive and sustainable system to control environmental conditions has been set up to maintain optimal humidity conditions. This action stopped the degradation of the showcase as well as the specimens and guarantees their preservation over time. Keywords: mineralogy, conservation, conditioning, salt, Cardona, Catalonia.La vitrina de las sales de Cardona es un mobiliario diseñado y construido en 1921 por Francesc Pardillo. Localizada en el edificio del Museo Martorell (Museo de Ciencias Naturales de Barcelona), expone y conserva una colección de ejemplares de rocas salinas procedentes de la montaña de sal de Cardona que fueron donadas a finales del siglo XIX por la Sra. Casilda de Salabert i Arteaga (Duquesa de Medinaceli) i el Sr. Miguel de Elías Marchal. El conjunto expositivo presenta un valor patrimonial muy significativo. Debido al paso del tiempo y a la falta de actuaciones, la vitrina dejó de conservar en óptimas condiciones los ejemplares y estos empezaron a alterarse al interactuar con la humedad ambiental, produciendo también una degradación generalizada del mobiliario. Para paliar dicha degradación, se ha llevado a cabo una restauración integral tanto del mobiliario como de los ejemplares, repetando al máximo el diseño original, realizando las mínimas intervenciones sobre las rocas y diseñando un sistema de control ambiental pasivo y sostenible para matener las condiciones óptimas de humedad relativa. Esta actuación ha frenado la degradación del conjunto expositivo y garantiza su conservación futura. Palabras clave: mineralogía, conservación, restauración, sales, Cardona, Cataluñ

Conservació i condicionament de la vitrina de les sals del Museu Martorell (Museu de Ciències Naturals de Barcelona): 1921-2018

La vitrina de les sals de Cardona és un mobiliari dissenyat i construït el 1921 per Francesc Pardillo. Localitzada a l’edifici del Museu Martorell (Museu de Ciències Naturals de Barcelona), exposa i preserva una col·lecció d’exemplars de roques salines procedents de la Muntanya de Sal de Cardona i que van ser donades a finals del segle XIX per la Sra. Casilda de Salabert i Arteaga (Duquessa de Medinaceli) i el Sr. Miguel De Elías Marchal. El conjunt expositiu presenta un valor patrimonial molt significatiu. Degut al pas del temps i a la falta d’actuacions, la vitrina va deixar de conservar en òptimes condicions els exemplars i aquests van començar a alterar-se a l’interactuar amb la humitat ambiental, produint també una degradació generalitzada del mobiliari. Per tal de pal·liar aquesta degradació, s’ha dut a terme una restauració integral tant del mobiliari com dels exemplars, respectant al màxim el disseny original, realitzant les mínimes intervencions sobre les roques i dissenyant un sistema de control ambiental passiu i sostenible per tal de mantenir les condicions òptimes d’humitat relativa. Aquesta actuació ha frenat la degradació del conjunt expositiu i garanteix la seva conservació futura. Paraules clau: mineralogia, conservació, restauració, sal, Cardona, Catalunya.The Cardona salts showcase was built and designed in 1921 by Francesc Pardillo. Located at the Museu Martorell building (Museu de Ciències Naturals de Barcelona) it exposes and preserves a collection of salt rocks from the Cardona Salt Mountain. These specimens were donated at the end of 19th century by Ms. Casilda de Salabert i Arteaga (Medinaceli Duchess) and Mr. Miguel De Elías Marchal and represent a collection with a significant heritage and historic value. Due to the trace of time and the lack of conditioning interventions, this showcase did not preserve the samples in optimal conditions. The specimens began an alteration process interacting with high relative humidity, also generating the general degradation of the showcase furniture. In order to stop this degradation, it has been carried out an integral conditioning of this showcase but also of the salt specimens. This process has been executed respecting the original design of the showcase and carrying out the minimum intervention into the rock samples. In addition, a new passive and sustainable system to control environmental conditions has been set up to maintain optimal humidity conditions. This action stopped the degradation of the showcase as well as the specimens and guarantees their preservation over time. Keywords: mineralogy, conservation, conditioning, salt, Cardona, Catalonia.La vitrina de las sales de Cardona es un mobiliario diseñado y construido en 1921 por Francesc Pardillo. Localizada en el edificio del Museo Martorell (Museo de Ciencias Naturales de Barcelona), expone y conserva una colección de ejemplares de rocas salinas procedentes de la montaña de sal de Cardona que fueron donadas a finales del siglo XIX por la Sra. Casilda de Salabert i Arteaga (Duquesa de Medinaceli) i el Sr. Miguel de Elías Marchal. El conjunto expositivo presenta un valor patrimonial muy significativo. Debido al paso del tiempo y a la falta de actuaciones, la vitrina dejó de conservar en óptimas condiciones los ejemplares y estos empezaron a alterarse al interactuar con la humedad ambiental, produciendo también una degradación generalizada del mobiliario. Para paliar dicha degradación, se ha llevado a cabo una restauración integral tanto del mobiliario como de los ejemplares, repetando al máximo el diseño original, realizando las mínimas intervenciones sobre las rocas y diseñando un sistema de control ambiental pasivo y sostenible para matener las condiciones óptimas de humedad relativa. Esta actuación ha frenado la degradación del conjunto expositivo y garantiza su conservación futura. Palabras clave: mineralogía, conservación, restauración, sales, Cardona, Cataluñ