Metamorphism on Chromite Ores from the Dobromirtsi Ultramafic Massif, Rhodope Mountains (SE Bulgaria)

Podiform chromitite bodies occur in highly serpentinized peridotites at Dobromirtsi Ultramafic Massif (Rhodope Mountains, southeastern Bulgaria). The ultramafic body is believed to represent a fragment of Palaeozoic ophiolite mantle. The ophiolite sequence is associated with greenschist - lower-temperature amphibolite facies metamorphosed rocks (biotitic gneisses hosting amphibolite). This association suggests that peridotites, chromitites and metamorphic rocks underwent a common metamorphic evolution. Chromitites at Dobromirtsi have been strongly altered. Their degree of alteration depends on the chromite/silicate ratio and to a lesser extent, on the size of chromitite bodies. Alteration is recorded in individual chromite grains in the form of optical and chemical zoning. Core to rim chemical trends are expressed by MgO- and Al2O3- impoverishment, mainly compensated by FeO and/or Fe2O3 increases. Such chemical variations correspond with three main alteration events. The first one was associated with ocean-floor metamorphism and was characterized by a lizardite replacement of olivine and the absence of chromite alteration. The second event took place during greenchist facies metamorphism. During this event, MgO- and SiO2-rich fluids (derived from low temperatura serpentinization of olivine and pyroxenes) reacted with chromite to form chlorite; as a consequence, chromite became altered to a FeO- and Cr2O3-rich, Al2O3-poor chromite. The third event, mainly developed during lower temperature amphibolite facies metamorphism, caused the replacement of the primary and previously altered chromite by Fe2O3-rich chromite (ferritchromite)

Un estudio de las fuentes de la «Lingüística cartesiana»: Ralph Cudworth (1617-1688)

This article studies three of the most relevant works by Ralph Cudworth (1617-1688), mentioned by Chomsky in his Cartesian Linguistics. Regarding methodology, we assume the pillars of the historiography of linguistics as exposed by Swiggers, and also Brekle’s division into internal and external dimensions, using the theory of textual series as the key instrument (Hassler; Zamorano Aguilar 2013). The hypothesis defended and demonstrated in this work is that Chomsky, in dealing with the Cudworthian theory –even though he includes some epistemologically fundamental elements– obviates key aspects of Cudworth’s contribution not only to 17th century English rationalist philosophy, but also to historiography in general. Thus, we observe, apart from the mention to just one of the works of Cudworth, the partiality in the description of his theory developed by Chomsky.En este artículo se realiza un estudio de tres de las obras más relevantes de Ralph Cudworth (1617-1688), mencionado por Chomsky en Lingüística cartesiana. Metodológicamente nos basamos en los pilares de la historiografía de la lingüística según Swiggers y la división en dimensión interna y externa de Brekle, utilizando como instrumento fundamental la teoría de las series textuales (Hassler; Zamorano Aguilar 2013). La hipótesis defendida y cuya demostración se desempeña en este trabajo es que el uso de la teoría cudworthiana por parte de Chomsky, si bien recoge algunos elementos epistemológicamente fundamentales, obvia aspectos claves para comprender la aportación de aquel no solo a la teoría racionalista inglesa del siglo XVII, sino también a la historiografía en general. En este sentido, percibimos, además de la alusión a una única obra de Cudworth, la parcialidad en la descripción de su teoría por parte de Chomsky

Diamond forms during low pressure serpentinisation of oceanic lithosphere

Diamond is commonly regarded as an indicator of ultra-high pressure conditions in Earth System Science. This canonical view is challenged by recent data and interpretations that suggest metastable growth of diamond in low pressure environments. One such environment is serpentinisation of oceanic lithosphere, which produces highly reduced CH4-bearing fluids after olivine alteration by reaction with infiltrating fluids. Here we report the first ever observed in situ diamond within olivine-hosted, CH4-rich fluid inclusions from low pressure oceanic gabbro and chromitite samples from the Moa-Baracoa ophiolitic massif, eastern Cuba. Diamond is encapsulated in voids below the polished mineral surface forming a typical serpentinisation array, with methane, serpentine and magnetite, providing definitive evidence for its metastable growth upon low temperature and low pressure alteration of oceanic lithosphere and super-reduction of infiltrated fluids. Thermodynamic modelling of the observed solid and fluid assemblage at a reference P-T point appropriate for serpentinisation (350 °C and 100 MPa) is consistent with extreme reduction of the fluid to logfO2 (MPa) = −45.3 (ΔlogfO2[Iron-Magnetite] = −6.5). These findings imply that the formation of metastable diamond at low pressure in serpentinised olivine is a widespread process in modern and ancient oceanic lithosphere, questioning a generalised ultra-high pressure origin for ophiolitic diamond.European Union (EU)Spanish Projects CGL2015-65824 RTI2018-099157-A-I00 PID2019-105625RB-C21 A.RNM.186.UGR18Spanish Government RYC-2015-17596Mexican research program CONACYT-Ciencia Basica A1-S-14574Mexican research program UNAM-PAPIIT IA-10141

Drag reduction on a blunt body by self-adaption of rear flexibly hinged flaps

We study the aerodynamics of a blunt-based body with rear flexibly-hinged rigid flaps, subject to a turbulent flow of Reynolds number Re = 12000, under aligned and cross flow conditions with yaw angle β = 0◦ and β = 4◦. To that aim, different values of the equivalent torsional stiffness are considered, to cover the range of reduced velocity U∗ = (0, 3.48] in water tank experiments. The effect of the angular deflection of plates on the drag and near wake flow is analyzed, experimentally and numerically. The results show that, in the range of U∗ herein considered, the plates undergo an inwards quasi-static, self-adaptive deflection, which is symmetric for yaw angles β = 0◦ and asymmetric for β = 4◦. In particular, the plates feature small mean deformation angles for values of U∗ < 1, whereas a sharp and monotonic increase of such deflection occurs for U∗ > 1, i.e. for lower values of the hinge’s stiffness, with an asymptotic trend towards the larger values of U∗. A critical value of reduced velocity of U∗ ≃ 0.96 is obtained as the instability threshold above which plates depart from their initial equilibrium position. The progressive streamlining of the trailing edge translates into significant reductions of the associated mean drag coefficients. Thus, reductions close to 19% with respect to reference static plates configurations are obtained for the most flexible case of U∗ = 3.48 for both β = 0◦ and β = 4◦. A close inspection of the near wake reveals that the inwards progressive mean displacement of the plates yields a reduction in the recirculation bubble size. A symmetric evolution of the recirculating bubble is observed for β = 0◦, whereas the bubble becomes asymmetric for β = 4◦, with a larger leeward clockwise vortex. In both cases, the drag coefficient is shown to vary linearly with the global aspect ratio of the recirculating bubble. The analysis of the numerical results shows that the reduced extension of the recirculating bubble significantly alters the formation length and intensity of the eddies size and associated pressure. It is observed that despite the local pressure decrease in the vortices shed from the trailing edges, the plates self adaption reduces their size and prevents the eddies from entering the cavity, thus, creating a dead flow region with a consequent pressure increase at the body base.Junta de Andalucia FEDER-UJA 1262764Universidad de JaenEuropean CommissionSpanish MCIN/AEI PDC2021-121288-I00European Union Next Generation EU/PRT

Banco de La Concepción: A new Natura 2000 Marine Site off Canary Islands

The main objective of the LIFE+ INDEMARES project is to contribute to the protection and sustainable use of the biodiversity in the Spanish seas through the identification of valuable areas for the Natura 2000 Network. The Spanish Institute of Oceanography (IEO) has been in charge of implementing scientific surveys to map sensitive habitats of seven of the ten INDEMARES areas, and to determine the fisheries footprint over these areas. Banco de La Concepci´on is one of the areas chosen to be depicted in the frame of INDEMARES project. Located at 71 km to the NE of Lanzarote, at the coordinates 29º 55’ Latitude N and 12º 45’ Longitude W, Banco de la Concepci´on raises from 2,541 m up to its summit at 170 m deep. The biological richness of Banco de la Concepci´on is very influenced by the deep water up-welling phenomena, which create a high productivity, attracting a multitude of pelagic species, such as cetaceans, turtles, sharks, and tunas looking for food. In its vicinity, fishery resources such as goraz, anglerfish, and hakes, are abundant, and a rich invertebrate fauna cohabits in their bottoms. Banco de la Concepci´on is a traditional fishing area of oceanic pelagic species, and very good to catch demersal fish; it is highly visited by Galician and Portuguese drifters and long liners that fish in Mauritania, and mainly by the Andalusian longliners. In general, its main impacts are related to uncontrolled fishing pressure. The available information on the anthropogenic impact of the area was scarce, and its level of research was very poor as well, before INDEMARES project. Methodology approach complies with a multidisciplinary perspective, having described the area from geological, oceanographic, biological and fisheries points of view. Several surveys have taken place since 2009 to 2013 at Banco de La Concepci´on waters. Traps, longlines, beam trawls, benthic dredges and box corers have been used to sample benthic fauna. These last two, plus EM 3002 multibeam echosounder, PS 18 parametric sub bottom profiler, EA600 monobeam sounder, Seapath 200 positioning sensor and SV Plus sound velocity calibration sensor were used to make a geophysical study which provides a range of environmental factors. CTD was used to depict physical conditions of the water column. Finally, Remote Operated Vehicle Liropus 2000 and different photogrammetric tugged sleds were used to make a great effort of visual sampling. Data from VMS (Vessel Monitoring System) were used, combined with interviews to users (fishers), to describe the fishery uses in the area. Results from all this field work provide enough information for the administrations to establish a new Natura 2000 area, trying to reconcile protection of biodiversity and artisanal local economic activities. This establishment should take place at the end of a process of public consultation to stakeholders which is taking place in the present and which will help to shape the future Management Plan which will give details about permitted and prohibited uses

Análisis de la actividad científica de la Comunidad Autónoma de la Región de Murcia. Biomedicina 1999-2005.

An analysis of scientific activity in Biomedicine in Murcia between 1999-2005 is presented

Sensitive Habitats and fishing footprint off Canary Islands seamounts Amanay and El Banquete

The main objective of the LIFE+ INDEMARES project is to contribute to the protection and sustainable use of the biodiversity in the Spanish seas through the identification of valuable areas for the Natura 2000 Network. The Spanish Institute of Oceanography (IEO) has been in charge of implementing scientific surveys to map sensitive habitats of seven of the ten INDEMARES areas, and to determine the fisheries footprint over these areas. Sur y Oriente de Fuerteventura y Lanzarote is one of the areas chosen to be depicted in the frame of INDEMARES project, although the study about benthic habitats and fishery footprint carried by IEO has restricted to Amanay and El Banquete Seamounts. El Banquete really is the extension of southern continental shelf while Amanay seamount is located at 25 km from Jand´ıa Lighthouse (S of Fuerteventura) and 55 km from Las Palmas de Gran Canaria, at the coordinates 28º 07’ Latitude N and 14º 44’ LongitudeW, both volcanic buildings raise from more than 2,000 m up to their summits at 25-30 m deep, separated by a 1.500 m deep channel. The biological richness of Amanay and El Banquete seamounts is very influenced by the deep water up-welling phenomena, which create a high productivity, attracting a multitude of pelagic species, such as cetaceans, turtles, sharks, and tunas looking for food. There is also a high influence from Saharian up-welling. Both the seamounts tops and their vicinities are often visited by a large artisanal local fishing fleet which profits of their fishery resources; also a rich invertebrate fauna cohabits in their bottoms. In general, its main impacts are related to uncontrolled fishing pressure, and maritime navigation. The available information on the anthropogenic impact of the area was scarce, and its level of research was very poor as well, before INDEMARES project. Methodology approach complies with a multidisciplinary perspective, having described the area from geological, oceanographic, biological and fisheries points of view. Several surveys have taken place since 2009 to 2013 at Amanay and El Banquete waters. Traps, longlines, beam trawls, benthic dredges and box corers have been used to sample benthic fauna. These last two, plus EM 3002 multibeam echosounder, PS 18 parametric sub bottom profiler, EA600 monobeam sounder, Seapath 200 positioning sensor and SV Plus sound velocity calibration sensor were used to make a geophysical study which provides a range of environmental factors. CTD was used to depict physical conditions of the water column. Finally, different photogrammetric tugged sleds were used to make a great effort of visual sampling. Data from VMS (Vessel Monitoring System) were used, combined with interviews to users (fishers), landing samplings and scientific observation onboard, to describe the fishery uses in the area

New and rare records of teleost fishes from the Cape Verde Islands (eastern-central Atlantic Ocean)

As a result of six exploratory surveys and several opportunistic catches in the Cape Verde Islands from a few metres to about 1000 m of depth, a list of 66 species of teleost fishes is given, six of which are first records from the archipelago: Gnathophis mystax (Congridae), Nezumia africana, Nezumia duodecim (Macrouridae), Ectreposebastes imus (Scorpaenidae), Paraliparis sp. (Liparidae) and Lappanella fasciata (Labridae). Additionally, data on six poorly-known species is also given: Myroconger compressus (Myrocongridae), Myrichthys pardalis, Phaenomonas longissima (Ophichthidae), Sphagemacrurus hirundo (Macrouridae), Gadella imberbis and Physiculus cyanostrophus (Moridae). Data includes distribution, habitat, morphometry and reproduction.Six campagnes exploratoires ainsi que quelques captures opportunistes réalisées de quelques mètres jusqu’à environ 1000 m de profondeur aux îles du Cap-Vert ont permis d’établir une liste comprenant 66 espèces de poissons téléostéens. Six espèces sont signalées pour la première fois aux îles du Cap-Vert : Gnathophis mystax (Congridae), Nezumia africana, Nezumia duodecim (Macrouridae), Ectreposebastes imus (Scorpaenidae), Paraliparis sp. (Liparidae) et Lappanella fasciata (Labridae). La présence de six autres espèces mal connues est confirmée pour cet archipel : Myroconger compressus (Myrocongridae), Myrichthys pardalis, Phaenomonas longissima (Ophichthidae), Sphagemacrurus hirundo (Macrouridae), Gadella imberbis et Physiculus cyanostrophus (Moridae). Les données présentées concernent la distribution, l’habitat, la morphométrie et la reproduction.Postprin

Acumulación de Ag, Cu y Ni en sedimentos en una cuenca semiárida como sub-producto de la mina de oro El Triunfo, Baja California Sur, México

The dispersal of Ag, Cu, and Ni in mine wastes (tailings and ash) was studied from the source of an abandoned gold mine at El Triunfo (Baja California Sur, Mexico) to the adjacent coast of the Pacific Ocean. The highest contamination levels of the studied elements were measured in one sample of the tailings (Ag: 247 mg kg-1; Cu: 1660 mg kg-1; Ni: 111 mg kg-1). Horizontal and vertical distributions of these elements were obtained from the analysis of surface sediments, tailings, a test pit, a sediment core, and dunes. The background levels of these elements were estimated from independent methods. Then, these regional background level calculations were used to determine the normalised enrichment factors (NEFs). Relatively high NEF values (averages of Ag, Cu, and Ni were 24.0, 3.0, and 1.4, respectively) indicated that the area close to the mine waste zone (up to about 18 km from the source area) was moderately to severely polluted. Moderate to null pollution (average NEFs of Ag, Cu, and Ni were 7, 2 and 1, respectively) was interpreted for the area at about 18-49 km from the mine waste zone. Vertical distributions of the elements in sediments of the overbank, the test pit in the mine zone, and the sediment core (at the discharge of the main arroyo Hondo–Las Gallinas–El Carrizal), also revealed enrichment of Ag, Cu, and Ni relative to the surface sediments. This study indicated that historic and contemporary contamination continues to impact the fluvial environment.Se estudió la dispersión de Ag, Cu, y Ni, en desechos mineros (jales y cenizas) desde su origen en la mina de oro abandonada de El Triunfo (Baja California Sur, México) hasta su desembocadura en la costa adyacente al Océano Pacífico. Los mayores niveles de la contaminación de los elementos estudiados se presentan en los jales (Ag: 247 mg kg-1; Cu: 1660 mg kg-1; Ni: 111 mg kg-1). Se obtuvieron distribuciones horizontales y verticales de estos elementos a partir de los análisis de sedimentos superficiales, de deterun jale, de un pozo de ensayo, de un testigo y en las dunas adyacentes a la desembocadura del arroyo. Los niveles de fondo fueron calculados considerando varios métodos independientes. Luego, con estos cálculos de niveles de fondo se determinaron los Factores de Enriquecimiento Normalizados (NEFs). Los valores relativamente altos de NEF (promedios de Ag, Cu and Ni de 24.0, 3.0 y 1.4, respectivamente) indicaron que el área situada cerca de la zona minera (aproximadamente 18 km de los desechos mineros abandonados) se encuentra de moderada a severamente contaminada. Una contaminación moderada a nula (NEFs promedio de Ag, Cu y Ni: 7, 2 y 1, respectivamente) fue determinada en el área comprendida entre los 18 y los 49 km medidos desde el distrito minero. Las distribuciones verticales de los elementos en los sedimentos de los jales y el pozo de ensayo en la zona minera, así como en el testigo analizado en la desembocadura del arroyo principal (Arroyo Hondo – Las Gallinas – El Carrizal), muestran mayor enriquecimiento de Ag, Cu y Ni, que los sedimentos superficiales adyacentes. Este estudio indica que la contaminación histórica y contemporánea está impactando el ambiente fluvial