Search results for "feature"

Review of Nd isotopic data and xenocrystic and detrital zircon ages from the pre-Variscan basement in the eastern Bohemian Massif: speculations on pa…

2000

Timing and Evolution of Cretaceous Island Arc Magmatism in Central Cuba: Implications for the History of Arc Systems in the Northwestern Caribbean

2011

AbstractSHRIMP and conventional zircon dating place temporal constraints on the evolution of the Cretaceous Volcanic Arc system in central Cuba. The arc has a consistent stratigraphy across strike, with the oldest and deepest rocks in the south (in tectonic contact with the ∼5–10-km-wide Mabujina Amphibolite Complex [MAC]) and younger rocks in the north. The MAC is thought to represent the deepest exposed section of the Cretaceous Volcanic Arc and its oceanic basement in Cuba. We undertook a single zircon geochronological study of five gneisses and two amphibolites from the MAC and seven rocks from the Manicaragua Batholith, which intrudes both the MAC and the Cretaceous Volcanic Arc. A SHR…

2020

Although volcanic eruptions represent short periods in the whole history of a volcano, the large amount of loose pyroclastic material produced, combined with aeolian processes, can lead to continuous, long-lasting reworking of volcanic products. Driven by wind, these processes significantly influence the geomorphology and prolong the impacts of eruptions on exposed communities and ecosystems. Since such phenomena are of interest to scientists from a range of disciplines (e.g. volcanology, atmospheric and soil sciences), a well-defined, common nomenclature is necessary to optimize the multidisciplinary characterisation of both processes and deposits. We, therefore, first describe ash wind-re…

Shifts in plankton assemblages promoted by free water surface constructed wetlands and their implications in eutrophication remediation

2015

Abstract Two units of free water surface constructed wetlands (FWSCWs) were created in 2009 in a Mediterranean protected site, the Albufera de Valencia Natural Park, to treat eutrophic inflows to the Albufera de Valencia lagoon, the largest coastal lagoon in the Iberian Peninsula, affected by cultural eutrophication. Data of phytoplankton and zooplankton biomass and richness of the inflows and outflows corresponding to the first 3.5 years of operation of the system have been analyzed to evaluate the role of plankton in the eutrophication reversion. The FWSCWs significantly reduced the exported microalgal biomass, stimulated the potential mixotrophic groups of phytoplankton such as Euglenoph…

Soil and Plant Nitrogen Pools as Related to Plant Diversity in an Experimental Grassland

2007

Increasing plant species richness decreases soil NO 3 - concentrations in experimental plant mixtures, but the role of particular plant functional groups has remained unclear. Most analyses have focused on particular times of the year or were restricted to NO 3 - . We tested whether plant species richness or particular plant functional groups affect the size of plant-available N pools in soil (KCl-extractable NO 3 - , dissolved inorganic N and organic N [DON] and total dissolved N [TDN] in soil solution) and N concentrations and pools in aboveground biomass. Furthermore, we assessed seasonal variations in the effects of plant species richness and plant functional groups. The experimental gr…

The effects of post-pasture woody plant colonization on soil and aboveground litter carbon and nitrogen along a bioclimatic transect.

2013

Abstract: We investigated the effects of woody plant colonization of abandoned pastures on soil and litter organic carbon (C) stocks and nitrogen (N) content along a bioclimatic transect in a semi-arid environment (Sicily, Italy). Soil samples were taken in three successional stages (grazed pasture, shrubland, forest) within each of three bioclimates (supramediterranean - “supra”, mesomediterranean - “meso”, thermomediterranean - “thermo”). Organic C and N in litter and soil (0-10 cm and 10-30 cm depth) were determined, as well as soil bulk density. Especially at 0-10 cm depth, changes in C and N contents along successional stages differed among bioclimates. Soil organic carbon (SOC) stock …

New lithostratigraphy for the Cantabrian Mountains: A common tectono-stratigraphic evolution for the onset of the Alpine cycle in the W Pyrenean real…

2019

The Pyrenean-Cantabrian Orogen arose through the collision of the Iberian and Eurasian plates, mostly in Cenozoic times. This orogen comprises two main mountain ranges, the Pyrenees to the east, and the Cantabrian Mountains to the west. To date, the early Alpine tectono-sedimentary phases preserved in the Cantabrian Mountains, of Permian and Triassic age, have been considered independently from the same phases in neighbouring basins of SW Europe, and even from the eastern part of the same orogeny (the Pyrenean orogeny). In consequence, the beginning of the Alpine cycle in the Cantabrian Mountains has been interpreted within a specific geodynamic context, far from the general evolutionary ph…

Incorporation of zeolitic imidazolate framework (ZIF-8)-derived nanoporous carbons in methacrylate polymeric monoliths for capillary electrochromatog…

2017

A series of metal organic frameworks-derived nanoporous carbons originating from zeolitic imidazolate framework-8 (ZIF-8) crystals as precursors have been prepared via varying the preparation conditions. The ZIF-8-derived carbons were subsequently admixed in the methacrylate monomers containing polymerization mixtures and polymerized to obtain monolithic columns for capillary electrochromatography (CEC). The effect of particle size and content of the ZIF-8-derived carbon materials in the polymerization mixture on the performance of the hybrid monolithic columns was investigated in detail. The resulting composites were characterized using scanning electron microscopy. Using short time UV-ini…

STOP 15: Morphology and internal structure of a ribbed moraine and drumlin remnant in the environs of Baldone, Central Latvian Lowland

2014

Rhyolitic dykes of Paros Island, Cyclades

2005

Abstract The discovery of rhyolitic dykes from the NE part of the island of Paros is described here for the first time. The dykes that can be mapped for a length of ca. 1.1 km are striking about 6° and 38° NE. The width reaches up to 11m maximum. The rhyolitic rocks are porphyric with a fine-grained matrix of mainly feldspar, quartz, some biotites and opaques. K-feldspar, biotite and plagioclase occur as phenocrysts, and mafic-intermediate enclaves are common. At the chilled margin in contact to the gneissic country rocks the dykes are vitric. There, the enclaves have been preserved from contact reaction with the melt and alteration effects and show primary igneous minerals such as clinopyr…