The Lomagundi-Jatuli carbon isotopic event recorded in the marble of the Tandilia System basement, Río de la Plata Craton, Argentina

The “Lomagundi-Jatuli event” corresponds to the most important δ13C positive anomaly (≥5‰) globally reported in Palaeoproterozoic marine carbonates (between ∼2.30 and 2.06 Ga). In the Tandilia System (Argentina), Río de la Plata Craton, this event was recorded in the basement marble of the San Miguel area. The calcite-diopside marble, hosted by biotite gneiss and intruded by 2.12 Ga garnet-leucogranite, was metamorphosed in amphibolite facies during the Transamazonian Cycle. PAAS-normalised rare-earth elements (REE) and Y for the carbonate rocks are HREE-enriched and display positive Eu and Y anomalies, typical of primary precipitates from a mixed hydrothermal-marine environment carbonate. Additionally, a truly negative Ce anomaly for all the samples indicates that the depositional environment was oxidising. Positive δ13C values ranging from +5.90 to +4.30‰ (V-PDB), and δ18O from +17.45 to +13.84‰ (V-SMOW) were determined in this marble, both gradually decreasing towards the contact with the leucogranites. These values indicate that devolatilization reactions took place during the crystallisation of a wollastonite-vesuvianite-grossular-diopside skarn generated by the leucogranite intrusions into the marble. δ18O values obtained from diopside and calcite crystals, in the marble sectors furthest from the contacts with leucogranite, allowed a 663–623 °C formation temperature to be calculated, considering oxygen in a calcite-diopside geothermometric pair. These temperatures are consistent with the metamorphic degree (amphibolite facies) reached in this portion of the basement. Although the San Miguel marble shows petrographic and mineralogical evidence of regional and contact metamorphism, important geochemical and isotopic characteristics, together with its estimated Palaeoproterozoic age, indicate that the marble protolith was a marine carbonate deposited during the “Lomagundi-Jatuli event”.Fil: Lajoinie, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Recursos Minerales; ArgentinaFil: Lanfranchini, Mabel Elena. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Recursos Minerales; ArgentinaFil: Recio, C.. Universidad de Salamanca; EspañaFil: Sial, A.N.. Federal University of Pernambuco; BrasilFil: Cingolani, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Ballivian Justiniano, Carlos Alberto. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Recursos Minerales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Etcheverry, Ricardo Oscar. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Recursos Minerales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin

Anarchism and the press in Lima: The case of "Los Parias"

This thesis explores the relationship between the anarchist press and the nascent labor movement in the Republic of Peru in the beginning of the twentieth century. The first anarchist newspaper that appeared in Peru in 1904, titled Los Parias, provides a detailed look into the ways in which this communications medium, thanks to its timely message and firm social commitment, was able to forge an alliance with the workers of Peru in order to work towards a more socially egalitarian society in an era often recognized as the "Aristocratic Republic;" a historical period were old aristocracies and new bourgeoisies controlled the nation. By analyzing this material, this thesis hopes to delve deeper into how anarchists and all those who became supporters of this ideology (i.e. workers??? associations, guilds, students, intellectuals, etc.) conceptualized their social condition and the solutions they championed in order to achieve a libertarian utopia. The collaboration between anarchists and the nascent labor movement resulted in the formulation of an anti-establishment rhetoric that served as a precursor to new radical social trends that appeared in Peru as the twentieth century marched along; trends that had a profound effect in the social landscape of the nation. We find in these pages a call for social redemption; a radical and revolutionary alternative to elite control

Fine-Tuning Arguments and Biological Design Arguments: Can the Theist Have Both?

There are at least two kinds of design arguments for theism: fine-tuning arguments and biological design arguments. Dougherty and Poston (2008) have argued that the success of one requires the failure of the other, and vice versa. The reason is that the success of these arguments hinges on the following crucial probability: the probability that biological life exists somewhere in the universe given that (a) our universe is finely tuned and that (b) biological development is unguided by intelligence. According to Dougherty and Poston, fine-tuning arguments require that the crucial probability is high while biological design arguments require that the crucial probability is low. As a result, at most one of these design arguments can factor into a cumulative case argument for theism. I argue that this is mistaken. Specifically, I show that fine-tuning arguments can succeed even if the crucial probability is low

Кераміка для техніки

The benthic invertebrates fauna of most of the saline lakes of the Sud Lipez region (Bolivia, Altiplano) has been until now quite unstudied. Samples collected during an extensive survey of 12 lakes and two small inflow rivers allow a first list of the main macroinvertebrates living in the biotopes. The heterogeneous nature of these saline lakes with their freshwater springs and phreatic inflows offers a variety of habitats to macroinvertebrates. The benthic fauna in lakes with salinity > 10 g l-1 is not so low in density but includes few species and is dominated by Orthocladinae and Podonominae larvae. In contrast, the freshwater springs and inflows are colonized by a diverse fauna with a mixture of both freshwater and saline taxa, but dominated by Elmidae and Amphipoda. The lakes are quite isolated and, apart from some cosmopolitan organisms, their fauna can be quite distinctive. (Résumé d'auteur

Schools of the Street: Hip-hop as Youth Pedagogy in Bolivia

The experience of hip-hop in El Alto, Bolivia is at once familiar as it shares much of the sound, symbols and oppositional aspects with youth counterparts around the world, and also unique insofar as it takes on an explicit educational dimension. In El Alto, an environment where schools are scarce, poverty and unemployment rife, and mistrust of government and elite institutions widespread, the practice and culture of hip-hop seem to be fulfilling a role of popular, non-institutionalized public sphere education. Hip-hop has served as a means for youth to narrate their stories, write alternative histories, and act pedagogically and politically, especially during the political mobilizations in the past decade. Through life histories of two of the young men involved in popularizing hip-hop locally, this paper analyzes youth as public pedagogues and the streets, songs, and local cultural centers as public sphere schools

30+ YEARS OF LAND COVER AND LAND USE CHANGE IN SOUTH AMERICA

The modification of the Earth’s surface constitutes the most impactful way in which humans affect their surrounding environment, with broad and lasting consequences. Changes in land cover accelerate biodiversity loss, contribute to climate change, and affect the provisioning of ecosystem services. Such negative environmental impacts can have important effects on human health and livelihoods. The South American continent, in particular, has undergone significant transformations over the past decade, due in large part to the conversion of natural land to more economically productive land uses, such as crops, pastures, and tree plantations. The agricultural commodities produced in South America are traded and consumed globally, and land will likely continue to be converted if demand for these commodities continues to rise. Despite the environmental and commercial importance of land cover and land use change dynamics in South America, the extent and rates of land change have not yet been thoroughly characterized and quantified. This dissertation aims to advance scientific knowledge on the extent and rates of change of important land covers and land uses, especially as they relate to the production of agricultural commodities, by leveraging the 34-year Landsat archive of Earth observation data. The general approach employed throughout follows a two-step process of mapping and sampling, in order to provide spatially explicit information on the patterns of land cover/land use change, as well as associated unbiased area estimates. This approach is first employed for the use-case of Brazilian cropland expansion from 2000 to 2014, and results show a near doubling of cropland area, the majority of which (80%) came about through the conversion of existing pastures. The methodology is then repeated at broader thematic, temporal, and geographic scales, resulting in area estimates of changes in cropland, pasture, plantation, natural tree regrowth, semi-natural land, tree cover and degraded tree cover from 1985 to 2018. Altogether, these changes amount to a 60% increase in human impact on natural land over the study period. Finally, an analysis and evaluation of the methodology employed for mapping and sampling when there is a multitude of target classes instead of a single one is provided as an assessment of methodological approaches

Centro educativo acuícola Kallfüko

ArquitectoEl proyecto a desarrollar centra el interés en abordar el potencial productivo del salmón, especialmente en la comuna de Calbuco (X Región de los Lagos), ya que es ahí donde no sólo se concentra gran parte de esta capacidad productiva, sino que también posee uno de los principales déficit educacionales en los estudios de educación media y una de las principales demandas por mano de obra técnica que respalde la labor de las empresas ahí emplazadas. Es así como estas características hacen de este lugar una zona con un gran potencial de transformación, no sólo en un centro de estudios y vivienda estudiantil, sino que también en un centro de investigación que esté íntimamente ligado a las empresas del sector en un proceso de retroalimentación educativa y financiera