18 research outputs found

    The granite and glacial landscapes of the Peneda-Gerês National Park

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    Granite and glacial landforms are presented as the main geomorphological landscape features of the Peneda-Gerês National Park. The park was established in 1971 and it is the only national park and most important protected area in Portugal. The aesthetic attractiveness is supported mainly by the distinct granite landscape of the Gerês and Peneda Mountains, where the post-orogenic Variscan Gerês gran- ite facies occurs. The rugged relief is poorly covered by vegetation, differentiating it from the surrounding moun- tainous areas and the most distinctive landforms are bornhardts, locally named as “medas”. Typical glacial landforms, such as U-shaped valleys, cirques and moraines, express the sheltered character of a low-altitude glaciation, which is of great significance in the context of the Pleistocene glaciation in Southern Europe.This work is co-funded by the European Union through the European Regional Development Fund, based on COMPETE 2020 (Programa Operacional da Competitividade e Inter nacionalização), project ICT (UID/GEO/04683/2013) with reference POCI-01-0145- FEDER-007690 and Portuguese national funds pro vided by Fundação para a Ciência e Tecnologi

    Paleogenomic Evidence for Multi-generational Mixing between Neolithic Farmers and Mesolithic Hunter-Gatherers in the Lower Danube Basin

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    The transition from hunting and gathering to farming involved profound cultural and technological changes. In Western and Central Europe, these changes occurred rapidly and synchronously after the arrival of early farmers of Anatolian origin [1-3], who largely replaced the local Mesolithic hunter-gatherers [1, 4-6]. Further east, in the Baltic region, the transition was gradual, with little or no genetic input from incoming farmers [7]. Here we use ancient DNA to investigate the relationship between hunter-gatherers and farmers in the Lower Danube basin, a geographically intermediate area that is characterized by a rapid Neolithic transition but also by the presence of archaeological evidence that points to cultural exchange, and thus possible admixture, between hunter-gatherers and farmers. We recovered four human paleogenomes (1.1× to 4.1× coverage) from Romania spanning a time transect between 8.8 thousand years ago (kya) and 5.4 kya and supplemented them with two Mesolithic genomes (1.7× and 5.3×) from Spain to provide further context on the genetic background of Mesolithic Europe. Our results show major Western hunter-gatherer (WHG) ancestry in a Romanian Eneolithic sample with a minor, but sizeable, contribution from Anatolian farmers, suggesting multiple admixture events between hunter-gatherers and farmers. Dietary stable-isotope analysis of this sample suggests a mixed terrestrial/aquatic diet. Our results provide support for complex interactions among hunter-gatherers and farmers in the Danube basin, demonstrating that in some regions, demic and cultural diffusion were not mutually exclusive, but merely the ends of a continuum for the process of Neolithization.This research was supported by a European Research Council (ERC) Starting Grant (ERC-2010-StG 263441) to R.P. G.G.-F. was also supported by MSC Individual Fellowship (NeoGenHeritage, grant no. 655478). E.R.J. was supported by a Herchel Smith Research Fellowship. M.H. and A.M. were supported by ERC consolidator grants 310763 GeneFlow and 647797 LocalAdaptation, respectively. V.S. was supported by the Gates Cambridge Trust. The work of C.L. was undertaken through the Partnerships in Priority Areas Program PN II, developed with the support of MEN-UEFISCDI (project no. PN-II-PTPCCA-2013-4-2302). A.G.-D. is supported by the research project BIOGEOS (CGL2014-57209-P) of the Spanish MINECO. The research of P.A., M.D.G., and L.D. on Los Canes is currently supported by the project CoChange (HAR2014-51830-P) of the Spanish State Plan for R+D+i (MINECO)

    Erosion Surface and Granitic Morphology in the Sierra de Lihuel Calel, Province of La Pampa, Argentina

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    Fil: Aguilera, Emilia Yolanda. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Sato, Ana María. Centro de Investigaciones Geológicas (CIG). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Llambías, Eduardo Jorge. Centro de Investigaciones Geológicas (CIG). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Tickyj, Hugo. Departamento de Ciencias Naturales. Facultad de Ciencias Exactas y Naturales. Universidad Nacional de La Pampa; Argentin

    Mediterranean-climate streams and rivers: geographically separated but ecologically comparable freshwater systems

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    Streams and rivers in mediterranean-climate regions (med-rivers in med-regions) are ecologically unique, with flow regimes reflecting precipitation patterns. Although timing of drying and flooding is predictable, seasonal and annual intensity of these events is not. Sequential flooding and drying, coupled with anthropogenic influences make these med-rivers among the most stressed riverine habitat worldwide. Med-rivers are hotspots for biodiversity in all med-regions. Species in med-rivers require different, often opposing adaptive mechanisms to survive drought and flood conditions or recover from them. Thus, metacommunities undergo seasonal differences, reflecting cycles of river fragmentation and connectivity, which also affect ecosystem functioning. River conservation and management is challenging, and trade-offs between environmental and human uses are complex, especially under future climate change scenarios. This overview of a Special Issue on med-rivers synthesizes information presented in 21 articles covering the five med-regions worldwide: Mediterranean Basin, coastal California, central Chile, Cape region of South Africa, and southwest and southern Australia. Research programs to increase basic knowledge in less-developed med-regions should be prioritized to achieve increased abilities to better manage med-rivers

    Mediterranean-climate streams and rivers: geographically separated but ecologically comparable freshwater systems

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    Pseudokarst and Speleothems in the Chihuido Granite, Province of Mendoza, Argentina

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    The core of the Chihuido Anticline is located precisely at Cerro Chihuido, Malargüe, southern Mendoza province, Argentina. This anticline represents the outcropping pre-Jurassic platform of the margin of the Neuquén Basin, which is composed of three volcano-sedimentary units separated by angular unconformities. The older unit corresponds to the volcano-sedimentary complex named as El Fortín, which concludes with the intrusion of a thick rhyolite-monzogranite dyke. The dyke, together with plutons corresponding to the Gondwana magmatism, is exposed on a paleosurface whose relief has been partly fossilized by much modern pyroclastic rocks. The thickness of the dyke varies from 0.2 km to almost 1 km. In this landscape, the dyke is the most remarkable topographic and geological characteristic, not only for its huge dimensions but als o for its numerous weathering cavities that provide it with a quite peculiar aspect. Typical pseudokarst landforms are represented by tafoni cavities. The nature of pseudokarst is portrayed by selective erosion along joint planes and andesite composition blocks included in the dyke. In the wall of some cavities within the almost vertical dyke, opal speleothems have been formed from silica released by rock weathering. The speleothems were studied by means of optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction. The study of these minor features of the granitic landscape, such as tafoni, and the associated speleothems, the description of their morphology, and the analysis of their composition are the main objectives of this chapter.Fil: Aguilera, Emilia Yolanda. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Carretero, Silvina Claudia. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rabassa, Jorge Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin

    Granitic caves from the Achala Batholith in the Province of Córdoba, Argentina: A study on three particular stories with a common past

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    The igneous or magmatic rocks, especially those with granitic composition, constitute a special type of geomorphological substrate. As fromits exposure on the Earth´s surface and the modelling that eventually takes placeon them, different landscapes with specific characteristics emerge where inherited and present shapes coexist making possible to reconstruct the landscape evolution of the massif. Traditionally, in the studies of granitic landscapes,only the forms observed on the surface are described, where as those that develop underground are not often taken into consideration. In this paper three caves are analysed in order to specify their particular origins and classify it according to its morphological characteristics and the genetic processes involved. These caves are located on the same scarp of the rock massif and, therefore, share a geological and geomorphological common history, which is shown in their hypothesis of evolution. In addition, based on the type of cavityand certain observations of their environments it is possible to establish a relative chronological order in their ages of formation. In this context, it is proven that these underground environments (as the other geographical accidents andgranitic landforms) are not chaotic but - on the contrary- they are structured ingeological and geomorphological processes over time and they respond to acommon evolutionary framework to the entire rock massif. More detailed studies on these environments can develop in new methodological tools to understand the geological history of the granitic landscape they are located in.Fil: García Aráoz, Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Geología Aplicada; ArgentinaFil: Madelon, Nicolás. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Pleitavino, Micaela Natalí. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Boretto, Gabriella Margherita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; ArgentinaFil: Cioccale, Marcela Alejandra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Geología Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
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