Results 171 to 180 of about 1,651,917 (208)
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The biogeochemistry of lipids in rivers of the Orinoco Basin
Geochimica et Cosmochimica Acta, 1995Abstract Water samples from rivers in the Orinoco Basin were examined in order to assess the biogeochemistry of particle-associated and dissolved lipids. Lipid fractions were characterised so as to determine their origin, speciation, variability in individual rivers, and their flux to the lower Orinoco River. Aliphatic hydrocarbons, ketones, alcohols,
Rudolf Jaffé +3 more
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Mercury in Populations of River Dolphins of the Amazon and Orinoco Basins
EcoHealth, 2019In the Amazon and Orinoco basins, mercury has been released from artisanal and industrial gold mining since the Colonial time, as well as a result of deforestation and burning of primary forest, that release natural deposits of methyl mercury, affecting the local aquatic vertebrate fauna.
F, Mosquera-Guerra +10 more
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Germanium and silicon in rivers of the Orinoco drainage basin
Nature, 1990CONTINENTAL weathering and mid-ocean-ridge hydrothermal circulation are the two main processes that release dissolved silicon to the ocean. It has been hypothesized1 that temporal variations in the relative strengths of these two processes might be estimated from the Ge/Si ratio of opal in marine sediments, because the chemistry of germanium is similar
Richard J. Murnane, Robert F. Stallard
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Fishes and aquatic habitats of the Orinoco River Basin: diversity and conservation
Journal of Fish Biology, 2016About 1000 freshwater fishes have been found so far in the Orinoco River Basin of Venezuela and Colombia. This high ichthyological diversity reflects the wide range of landscapes and aquatic ecosystems included in the basin. Mountain streams descend from the high Andes to become rapid‐flowing foothill rivers that burst out upon vast savannah flatlands ...
C A, Lasso +2 more
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The freshwater habitats, fishes, and fisheries of the Orinoco River basin
Aquatic Ecosystem Health & Management, 2007The Orinoco River of Venezuela and Colombia is one of the great rivers of the world, ranking third by discharge after the Amazon and the Congo. In the Orinoco basin, riverine and floodplain habitats, including riparian forests, play key roles in the conservation of biodiversity and support commercial, sport, and subsistence fisheries. The basin's three
Marco A. Rodríguez +3 more
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Atmospheric Environment, 2019
Abstract The “Llanos” is a complex savanna ecosystem that occupies most of the Orinoco River Basin, from the Colombian Andes foothills almost to the Orinoco River Delta at the Atlantic Ocean in Venezuela. It undergoes periodic, human-induced and natural biomass burning during the dry season, which is shorter in Colombia.
Dien Wu +2 more
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Abstract The “Llanos” is a complex savanna ecosystem that occupies most of the Orinoco River Basin, from the Colombian Andes foothills almost to the Orinoco River Delta at the Atlantic Ocean in Venezuela. It undergoes periodic, human-induced and natural biomass burning during the dry season, which is shorter in Colombia.
Dien Wu +2 more
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Orinoquia: The Archaeology of the Orinoco River Basin
Journal of World Prehistory, 2002Orinoquia is one of the most important riverine ecosystems complexes of the world. However, it has been seldom recognized as an ecological or historical entity in general accounts of South American archaeology. This essay reviews systematically and comparatively the archaeology of Orinoquia, by discussing research done from the 1940s onwards in all the
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Orinoco and Amazon River sediment input to the eastern Caribbean Basin
Marine Geology, 1985Abstract Carbonate and mineralogic analyses of piston cores from Aves Ridge, eastern Caribbean Basin, reveal climatically modulated relationship among Quaternary carbonate deposition and terrigenous sediment influxes from the Orinoco and Amazon Rivers. Low carbonate content and dark sediment color, extending into the Pleistocene, suggest considerable
Frederick A. Bowles, Peter Fleischer
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Orinoco revisited: Comprehensive analysis of the Orinoco River basin present and future hydroclimate
AtmósferaThe Orinoco River basin, ranked as South America’s third-largest catchment, is pivotal in contributing to the Atlantic Ocean’s water volume. This study provides a comprehensive update on the basin’s surface water balance, examining trends using gridded precipitation and total evaporation datasets.
Alejandro Builes-Jaramillo +3 more
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First-Cycle Quartz Arenites in the Orinoco River Basin, Venezuela and Colombia
The Journal of Geology, 1988Modern first-cycle quartz arenites are forming in the Orinoco drainage basin by at least two distinct mechanisms. Common to both mechanisms is an environment of intense chemical weathering and extended time over which weathering can occur. In the Llanos (Andean foreland basin), extended time is provided by temporary storage of orogenically derived ...
Mark J. Johnsson +2 more
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