Petrologic features of mesoproterozoic lamprophyric dykes from Montevideo (Piedra Alta terrane, South Uruguay)

Mafic dykes of lamprophyric affinity cropping out along the coastal area of Montevideo city are described. These dykes trend N75º-85º and crosscut 2.1 Ga Paleoproterozoic metamorphic units of the Rio de la Plata craton. They show mainly porphyritic textures with phlogopite and clinopyroxene macrocrysts in a groundmass composed of carbonates, phlogopite, augite, and feldspathoids. Ocellar structures filled with leucite, carbonates, and fibrous alkaline amphibole are present. The mineralogical assembly allows their classification as lamprophyres (minettes), but according to their chemical nature, they can be classified as alkaline lamprophyres. A crystallization age of 1.42 Ga by Ar-Ar method (on biotite/phlogopite) was obtained

Ancient Landscapes of Uruguay

In this chapter, based on the available geological information, a model for the genesis and evolution of the Uruguayan landscape is proposed. A structural framework of the landscape evolution is provided and the record of such evolution in the most representative geological units is considered. A brief summary of the Uruguayan geology and its location in the regional context is performed, from Precambrian to Cenozoic times.From the analysis of the geological record, it may be observed that the climate was very arid during part of the Jurassic and the Early Cretaceous. Together with the lava flows of the Arapey Formation, the climate became less arid as the Gondwana continents were becoming apart from each other. However, the geological record suggests that semiarid climates were still prevailing. In the Middle Cretaceous, semiarid and wetter climates progressively alternated, until the Early Tertiary, when very wet and warm conditions were established, in coincidence with the ?Paleocene Eocene Thermal Maximum (PETM)?, followed by semiarid climates in the Oligocene, wetter conditions in the Miocene and semiarid again in the Pliocene, with alternating semiarid and humid conditions during the entire Quaternary.On the basis of the paleoclimatic evolution, the development of relief is discussed, considering as bases for the analysis the different morphostructural units in which the country is divided. Due to their size, shape and location (passive margin) of Uruguay, climate uniformity is assumed for each period throughout the entire territory. It is also assumed that the surfaces around elevations of 500 meters correspond to relicts of probably pre-Cretaceous etchplains, strongly denudated, which are observed only in the surroundings of Aiguá.The landforms situated below the oldest surfaces, for instance those below 320 m a.s.l. in the Easthern Hills Regions (Sierra del Este), correspond to a new generation of geomorphological surfaces that may be considered of Cretaceous age, according to the information presently available. This surface may be correlated with the oldest surface developed on top of the lava flows of the Arapey Formation.The extremely warm and wet climate of the Eocene prepared the conditions for the planation processes that covered most of the Uruguayan territory during the Oligocene, generating pediplains which were later reworked during the Late Cenozoic, up to the Quaternary, generating a landscape of smooth hills.The morphogenetic potential of each morphostructural region determined the available energy of the resulting landscape, being this at a minimum in the Santa Lucía Basin, which continued to be under subsidence condition until the Tertiary, and almost non-existant in the Laguna Merín Basin, where subsidence remains active until the Holocene.Fil: Panario, Daniel. Universidad de la República; UruguayFil: Gutierrez, Ofelia. Universidad de la República; UruguayFil: Bettucci Sanchez, Leda. Universidad de la República; UruguayFil: Peel, Elena. Universidad de la República; UruguayFil: Oyhantcabal, Pedro. Universidad de la República; UruguayFil: Rabassa, Jorge Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

El terreno Nico-Pérez (Uruguay) y su herencia arcaica y paleoproterozoica

A U-Pb SHRIMP zircon geochronological study was carried out in the Nico Pérez Terrane in the central-eastern portion of Uruguay with the aim of constraining its geological evolution and its cratonic affinity. Nico Pérez Terrane is made up by a mosaic of tectonic blocks with diferente lithologies and sizes. This terrane is limited to the west by the Piedra Alta Terrane through the Sarandí del Yí shear zone, and to the east, is in tectonic contact through the Retamosa thrust with the Dom Feliciano Belt (Brasiliano orogenic cycle). Lithologically, the Nico Pérez Terrane is composed by medium to high grade metamorphic rock contained in three tectonic blocks (Pavas, Valentines and Rivera blocks) represented mainly by granitoids, as well as ortho and parametamorphic rocks, such as amphibolites, metapyroxenites, BIFs, schists, quartzites with fuchsite, among others. Archean inheritance, Rhyacian, Statherian, and Neoproterozoic magmatic ages are reported here. Similar ages, which show Archaean inheritance and Neoproterozoic imprint, reported in units of the Piedra Alta Terrane modify the idea that the Río de La Plata Craton only corresponds to a juvenile Paleoproterozoic tectonic unit. This, together with recently published geophysical information, supports the cratonic affinity of the Nico Pérez Terrane with the Río de La Plata Craton.Un estudio geocronológico U-Pb SHRIMP en circón fue realizado en rocas del Terreno Nico Pérez, con el objetivo de circunscribir la evolución geológica y su afinidad cratónica. Este terreno, localizado en la porción central del Uruguay, está constituído por un mosaico de tres bloques tectónicos y se encuentra limitado al oeste por el Terreno Piedra Alta a través de la zona de cizallamiento Sarandí del Yí. Al este, se encuentra en contacto tectónico a través del corrimiento Retamosa con el Cinturón Dom Feliciano (Ciclo Orogénico Brasiliano). Litológicamente, el Terreno Nico Pérez está compuesto por rocas metamórficas de grado medio a alto (bloques Pavas, Valentines y Rivera) representados principalmente por granitoides, así como por rocas orto- y parametamórficas, tales como anfibolitas, metapiroxenitas, BIFs, esquistos, cuarcitas con fucsita, entre otras. Se presenta en este trabajo un conjunto de edades magmáticas que poseen herencia arqueana, y edades riacianas, estaterianas y neoproterozoicas. Edades similares a estas, que muestran herencia arqueana e impronta neoproterozoica, reportadas en unidades del Terreno Piedra Alta, modifican la idea de que el Cratón del Río de La Plata corresponde a una unidad tectónica paleoproterozoica juvenil. Esto, junto con la información geofísica publicada recientemente, respalda la afinidad cratónica del Terreno Nico Pérez con el Cratón del Río de La Plata

Electrical structure of the lithosphere from Rio de la Plata craton to Paraná basin: amalgamation of cratonic and refertilized lithospheres in SW Gondwanaland

We conducted a magnetotelluric (MT) study from Paleoproterozoic Rio de la Plata Craton, in Uruguay, toward Paleozoic-Mesozoic Paraná Basin, in Brazil. The 850-km-long MT transect comprises 35 evenly spaced broadband electromagnetic soundings sites. In the Paraná Basin, 11 additional long-period measurements were acquired to extend the maximum depth of investigation. All data were inverted using two- and three-dimensional approaches obtaining the electrical resistivity structure from the surface down to 200 km. The Rio de la Plata Craton is>200-km thick and resistive (~2,000Ωm). Its northern limit is electrically defined by a lithosphere scale lateral transition and lower crust conductive anomalies (1–10Ωm) interpreted as a Paleoproterozoic suture at the southern edge of Rivera-Taquarembó Block. The latter is characterized by an approximately 100-km thick and moderate resistive (>500Ωm) upper mantle. The Ibaré shear zone is another suture where an ocean-ocean subduction generated the 120-km thick and resistive (>1,000Ωm) São Gabriel juvenile arc. Proceeding northward, a 70- to 80-km thick, 150-km wide, and inclined resistive zone is imaged. This zone could be remnant of an oceanic lithosphere or island arcs accreted at the southern border of Paraná Basin. The MT transect terminates within the southern Paraná Basin where a 150- to 200-km-thick less resistive lithosphere (<1,000Ωm) may indicate refertilization processes during plate subduction and ocean closure in Neoproterozoic-Cambrian time. Our MT data support a tectonic model of NNE– SSW convergence for this segment of SW Gondwanaland

Mesozoic magmatism in east uruguay: petrological constraints related to the sierra san miguel region

This work presents new results of a detailed geological and structural investigation focusing the easternmost Uruguayan Mesozoic magmatic occurrences related to the south Atlantic opening. Lithological descriptions, their stratigraphic relationships and complimentary lithochemical characterizations carried out in the San Miguel region (East Uruguay) are presented. Three volcanic/sub-volcanic units have been recognized. The felsic volcanic association is composed by rhyolitic - dacitic flows, mainly with porphyritic textures and sub-alkalinenature and related pyroclastic rocks. The felsic sub-volcanic association is characterized by granophyres of about 25 km2 of exposed area, cross- cut by mafic and felsic dykes. Finally, a mafic association has been identified characterized by dykes and a small intrusion of gabbroic composition.All these units are Mesozoic in age (130 - 127 Ma) and according to their chemical nature they correspond tosub-alkaline to weak peralkaline magmas

Preventing or inventing? Understanding the effects of non-prescriptive design briefs

© 2016, The Author(s). This paper discusses observations of an architecture and environmental engineering undergraduate design studio project assigned to 4th year students at a UK university. In the UK, most architecture courses are characterised by a high proportion of design studio teaching supported by varying amount of technical modules that include environmental and construction learning. Recent scholarship on sustainability education in architecture, discusses the necessity for new approaches that enhance transdisciplinarity, autonomy and independent decision-making. However, despite increasing importance to both practice and policy, few empirical or theoretical examples account for the implications or experiences of such an approach. This study presents the experiences of an architecture and environmental engineering design studio whereby studio activities are closely interlinked with technical engineering enquiry and experiment. Specifically, the research examines the challenges and opportunities students face when assigned a design project that attempts to translate independently derived briefs into novel architectural environmentally engineered interpretations. The analysis draws on a series of ethnographic narrative and visual observations carried over a period of 6months. The implications of the findings are threefold. First, the analysis shows the opportunities an integrated cross-disciplinary approach can offer, where the gap between creative and technical domains is narrowed. Second, the study presents some of the challenges faced by increased autonomy and lack of prescription that students encounter. Third, the paper contributes to an emerging agenda of sustainability education in the built environment by offering valuable insights into the benefits and difficulties cross-disciplinary approaches pose to architectural education

QUIJOTE scientific results - VI. The Haze as seen by QUIJOTE

The Haze is an excess of microwave intensity emission surrounding the Galactic Centre. It is spatially correlated with the γ -ray Fermi bubbles, and with the S-PASS radio polarization plumes, suggesting a possible common provenance. The models proposed to explain the origin of the Haze, including energetic events at the Galactic Centre and dark matter decay in the Galactic halo, do not yet provide a clear physical interpretation. In this paper, we present a reanalysis of the Haze including new observations from the Multi-Frequency Instrument (MFI) of the Q-U-I Joint TEnerife (QUIJOTE) experiment, at 11 and 13 GHz. We analyse the Haze in intensity and polarization, characterizing its spectrum. We detect an excess of diffuse intensity signal ascribed to the Haze. The spectrum at frequencies 11 GHz ≤ ν ≤ 70 GHz is a power law with spectral index βH = −2.79 ± 0.08, which is flatter than the Galactic synchrotron in the same region (βS = −2.98 ± 0.04), but steeper than that obtained from previous works (βH ∼ −2.5 at 23 GHz ≤ ν ≤ 70 GHz). We also observe an excess of polarized signal in the QUIJOTE-MFI maps in the Haze area. This is a first hint detection of polarized Haze, or a consequence of curvature of the synchrotron spectrum in that area. Finally, we show that the spectrum of polarized structures associated with Galactic Centre activity is steep at low frequencies (β ∼ −3.2 at 2.3 GHz ≤ ν ≤ 23 GHz), and becomes flatter above 11 GHz.The QUIJOTE experiment is being developed by the Instituto de Astrofisica de Canarias (IAC), the Instituto de Fisica de Cantabria (IFCA), and the Universities of Cantabria, Manchester and Cambridge. We thank the staff of the Teide Observatory for invaluable assistance in the commissioning and operation of QUIJOTE. Partial financial support was provided by the Spanish Ministry of Science and Innovation under the projects AYA2007-68058-C03-01, AYA2007- 68058-C03-02, AYA2010-21766-C03-01, AYA2010-21766-C03-02, AYA2014-60438-P, ESP2015-70646-C2-1-R, AYA2017-84185-P, ESP2017-83921-C2-1-R, AYA2017-90675-REDC (co-funded with EU FEDER funds), PGC2018-101814-B-I00, PID2019-110610RBC21, PID2020-120514GB-I00, IACA13-3E-2336, IACA15-BE3707, EQC2018-004918-P, the Severo Ochoa Programs SEV-2015- 0548 and CEX2019-000920-S, the Maria de Maeztu Program MDM2017-0765, and by the Consolider-Ingenio project CSD2010-00064 (EPI: Exploring the Physics of Inflation). We acknowledge support from the ACIISI, Consejeria de Economia, Conocimiento y Empleo del Gobierno de Canarias and the European Regional Development Fund (ERDF) under grant with reference ProID2020010108. This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement number 687312 (RADIOFOREGROUNDS). This research made use of computing time available on the high-performance computing systems at the IAC. We thankfully acknowledge the technical expertise and assistance provided by the Spanish Supercomputing Network (Red Española de Supercomputacion), as well as the computer resources used: the Deimos/Diva Supercomputer, located at the IAC. FG acknowledges funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 101001897). EdlH acknowledges partial financial support from the Concepción Arenal Programme of the Universidad de Cantabria. FP acknowledges support from the Spanish State Research Agency (AEI) under grant number PID2019-105552RB-C43. BR-G acknowledges ASI-INFN Agreement 2014-037-R.0. DT acknowledges the support from the Chinese Academy of Sciences President’s International Fellowship Initiative, Grant N. 2020PM0042. This work has made use of S-band Polarisation All Sky Survey (S-PASS) data. Some ofthe resultsin this paper have been derived using the HEALPIX (Gorski et al. 2005) and HEALPY (Zonca et al. 2019) packages. We also use NUMPY (Harris et al. 2020), and MATPLOTLIB (Hunter 2007)

QUIJOTE scientific results - VII. Galactic AME sources in the QUIJOTE-MFI northern hemisphere wide survey

The QUIJOTE-MFI Northern Hemisphere Wide Survey has provided maps of the sky above declinations −30◦ at 11, 13, 17, and 19 GHz. These data are combined with ancillary data to produce Spectral Energy Distributions in intensity in the frequency range 0.4–3 000 GHz on a sample of 52 candidate compact sources harbouring anomalous microwave emission (AME). We apply a component separation analysis at 1◦ scale on the full sample from which we identify 44 sources with high AME significance. We explore correlations between different fitted parameters on this last sample. QUIJOTE-MFI data contribute to notably improve the characterization of the AME spectrum, and its separation from the other components. In particular, ignoring the 10–20 GHz data produces on average an underestimation of the AME amplitude, and an overestimation of the free–free component. We find an average AME peak frequency of 23.6 ± 3.6 GHz, about 4 GHz lower than the value reported in previous studies. The strongest correlation is found between the peak flux density of the thermal dust and of the AME component. A mild correlation is found between the AME emissivity (AAME/τ250) and the interstellar radiation field. On the other hand no correlation is found between the AME emissivity and the free–free radiation Emission Measure. Our statistical results suggest that the interstellar radiation field could still be the main driver of the intensity of the AME as regards spinning dust excitation mechanisms. On the other hand, it is not clear whether spinning dust would be most likely associated with cold phases of the interstellar medium rather than with hot phases dominated by free–free radiation.We thank the referee of this article, Simon Casassus, for his comments that help to improve the communication of some of the concepts presented in this work. We thank the staff of the Teide Observatory for invaluable assistance in the commissioning and operation of QUIJOTE. The QUIJOTE experiment is being developed by the Instituto de Astrofisica de Canarias (IAC), the Instituto de Fisica de Cantabria (IFCA), and the Universities of Cantabria, Manchester and Cambridge. Partial financial support was provided by the Spanish Ministry of Science and Innovation under the projects AYA2007-68058-C03-01, AYA2007-68058-C03-02, AYA2010-21766-C03-01, AYA2010-21766-C03-02, AYA2014-60438-P, ESP2015-70646-C2-1-R, AYA2017-84185-P, ESP2017-83921-C2-1-R, AYA2017-90675-REDC (co-funded with EU FEDER - Fondo Europeo de Desarrollo Regional funds), PGC2018-101814-B-I00, PID2019-110610RB-C21, PID2020-120514GB-I00, IACA13-3E-2336, IACA15-BE-3707, EQC2018-004918-P, the Severo Ochoa Programs SEV-2015-0548 and CEX2019-000920-S, the Maria de Maeztu Program MDM-2017-0765, and by the Consolider-Ingenio project CSD2010-00064 (EPI: Exploring the Physics of Inflation). We acknowledge support from the ACIISI, Consejeria de Economia, Conocimiento y Empleo del Gobierno de Canarias and the European Regional Development Fund (ERDF) under grant with reference ProID 2020010108. This project has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement number 687312 (RADIOFOREGROUNDS).FP acknowledges the European Commission under the Marie Sklodowska-Curie Actions within the European Union's Horizon 2020 research and innovation programme under Grant Agreement number 658499 (PolAME). FP acknowledges support from the Spanish State Research Agency (AEI) under grant numbers PID2019-105552RB-C43. FG acknowledges funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No 101001897). EdlH acknowledge partial financial support from the Concepcion Arenal Programme of the Universidad de Cantabria. BR -G acknowledges the Agenzia Spaziale Italiana - Istituto Nazionale di Fisica Nucleare (ASI-INFN) Agreement 2014-037-R.0. DT acknowledges the support from the Chinese Academy of Sciences President's International Fellowship Initiative, Grant No. 2020PM0042. We acknowledge the use of data from the Planck/ESA mission, downloaded from the Planck Legacy Archive, and of the Legacy Archive for Microwave Background Data Analysis (LAMBDA). Support for LAMBDA is provided by the NASA Office of Space Science. Some of the results in this paper have been derived using the HEALPIX (Gorski et al. 2005 ) package

Principles of International Law Relevant for Consideration in the Design and Implementation of Trade-Related Climate Measures and Policies. Report of an International Legal Expert Group.

The report offers independent guidance for governments and stakeholders by eminent legal experts on principles of international law relevant for consideration in the design and implementation of trade-related climate measures and policies. The report reviews a set of recognized principles of international law that the expert group deems especially relevant for consideration including: Sovereignty; Prevention; Cooperation; Prohibition of Arbitrary & Unjustifiable Discrimination; Sustainable Development, Equity, & CBDR-RC; and Transparency & Consultation. The vision driving this report is that shared understandings on such principles could help foster dialogue and international cooperation on the design and implementation of trade-related climate measures and policies in the context of sustainable development priorities. According to the expert group, trade-related climate measures and policies should be approached as legal hybrids. Their rationale, design, and the debates about them draw from different areas of international law relating to the environment, climate, international trade and general international law. The principles are analysed in a way that presents them as cumulative and simultaneously applicable, in a mutually supportive and coherent manner, giving full effect to all relevant parts of international law, insofar as possible