965 resultados para Muri-Mountains


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Knowledge about vegetation and fire history of the mountains of Northern Sicily is scanty. We analysed five sites to fill this gap and used terrestrial plant macrofossils to establish robust radiocarbon chronologies. Palynological records from Gorgo Tondo, Gorgo Lungo, Marcato Cixé, Urgo Pietra Giordano and Gorgo Pollicino show that under natural or near natural conditions, deciduous forests (Quercus pubescens, Q. cerris, Fraxinus ornus, Ulmus), that included a substantial portion of evergreen broadleaved species (Q. suber, Q. ilex, Hedera helix), prevailed in the upper meso-mediterranean belt. Mesophilous deciduous and evergreen broadleaved trees (Fagus sylvatica, Ilex aquifolium) dominated in the natural or quasi-natural forests of the oro-mediterranean belt. Forests were repeatedly opened for agricultural purposes. Fire activity was closely associated with farming, providing evidence that burning was a primary land use tool since Neolithic times. Land use and fire activity intensified during the Early Neolithic at 5000 bc, at the onset of the Bronze Age at 2500 bc and at the onset of the Iron Age at 800 bc. Our data and previous studies suggest that the large majority of open land communities in Sicily, from the coastal lowlands to the mountain areas below the thorny-cushion Astragalus belt (ca. 1,800 m a.s.l.), would rapidly develop into forests if land use ceased. Mesophilous Fagus-Ilex forests developed under warm mid Holocene conditions and were resilient to the combined impacts of humans and climate. The past ecology suggests a resilience of these summer-drought adapted communities to climate warming of about 2 °C. Hence, they may be particularly suited to provide heat and drought-adapted Fagus sylvatica ecotypes for maintaining drought-sensitive Central European beech forests under global warming conditions.

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A continuous record of atmospheric lead since 12,370 carbon-14 years before the present (14C yr BP) is preserved in a Swiss peat bog. Enhanced fluxes caused by climate changes reached their maxima 10,590 14C yr BP (Younger Dryas) and 823014C yr BP. Soil erosion caused by forest clearing and agricultural tillage increased lead deposition after 532014C yr BP. Increasing lead/scandium and decreasing lead-206/lead-207 beginning 3000 14C yr BP indicate the beginning of lead pollution from mining and smelting, and anthropogenic sources have dominated lead emissions ever since. The greatest lead flux (15.7 milligrams per square meter per year in A.D. 1979) was 1570 times the natural, background value (0.01 milligram per square meter per year from 8030 to 5320 14C yr BP).

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from the journals of the late J. Frederick Elton, F.R.G.S., H.B.M. Consul at Mozambique ; edited and compiled by H.B. Cotterill

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The Byrd Glacier discontinuity us a major boundary crossing the Ross Orogen, with crystalline rocks to the north and primarily sedimentary rocks to the south. Most models for the tectonic development of the Ross Orogen in the central Transantarctic Mountains consits of two-dimensional transects across the belt, but do not adress the major longitudinal contrast at Byrd Glacier. This paper presents a tectonic model centering on the Byrd Glacier discontinuity. Rifting in the Neoproterozoic producede a crustal promontory in the craton margin to the north of Byrd Glacier. Oblique convergence of the terrane (Beardmore microcontinent) during the latest Neroproterozoic and Early Cambrian was accompanied by subduction along the craton margin of East Antarctica. New data presented herein in the support of this hypothesis are U-Pb dates of 545.7 ± 6.8 Ma and 531.0 ± 7.5 Ma on plutonic rocks from the Britannia Range, subduction stepped out, and Byrd Glacier. After docking of the terrane, subduction stepped out, and Byrd Group was deposited during the Atdabanian-Botomian across the inner margin of the terrane. Beginning in the upper Botomian, reactivation of the sutured boundaries of the terrane resulted in an outpouring of clastic sediment and folding and faulting of the Byrd Group.

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Los arquitectos trascendemos a partir de nuestras obras y continuamos viviendo a través de ellas… Es así si no media una topadora y gente con poco conocimiento a cargo. Lo que comento tiene relación con el triste anuncio de ARQ (24/7/13) sobre la demolición de la comisaría en Santo Pipó, Misiones. Integrante del grupo formado por Boris Davinovic, Augusto Gaido, Francisco Rossi y Clorindo Testa, ordenados alfabéticamente, así figuran en los planos enviados al desarrollar el proyecto luego de ganar el concurso nacional de anteproyectos para puestos de salud y comisarías, es decir que aún no era el famoso arquitecto, antes incluso del Banco de Londres, la obra que lo proyectó nacional e internacionalmente. Los concursos organizados por la provincia fueron para consolidarse, ya que al ser Territorio Nacional no tenía contenedores arquitectónicos de suficiente jerarquía para alojar las funciones del poder provincial, salvo dos y ambos en Posadas: la Casa del Gobernador de Corrientes, de fin del siglo anterior y el edificio construido en 1944 para la Feria Nacional de Turismo y Yerba Mate que luego se reformulará para la Legislatura. Es así como estos concursos cubrirán el territorio provincial de obras destinadas a los más variados fines, pero con un lenguaje predominante y común. En ese cruce entre arquitectura y política, ¿por qué el lenguaje identitario de ese tiempo histórico fue el del Movimiento Moderno? En cierto sentido heroico apelaba a la construcción de un significado nuevo que dejando atrás las propuestas arquitectónicas del pasado se proyectara hacia el futuro interpelando las categorías fundacionales y alejándose de la tentación de extraer analogías de la impronta preliminar que habilitaba un eclecticismo romántico.

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The Prince Charles Mountains have been subject to extensive geological and geophysical investigations by former Soviet, Russian and Australian scientists from the early 1970s. In this paper we summarise, and review available geological and isotopic data, and report results of new isotopic studies (Sm-Nd, Pb-Pb, and U-Pb SHRIMP analyses); field geological data obtained during the PCMEGA 2002/2003 are utilised. The structure of the region is described in terms of four tectonic terranes. Those include Archaean Ruker, Palaeoproterozoic Lambert, Mesoproterozoic Fisher, and Meso- to Neoproterozoic Beaver Terranes. Pan-African activities (granite emplacement and probably tectonics) in the Lambert Terrane are reported. We present a summary of the composition of these terranes, discuss their origin and relationships. We also outline the most striking geological features, and problems, and try to draw attention to those rocks and regional geological features which are important in understanding the composition and evolution of the PCM and might suggest targets for further investigations.