The Neuquén River () is the second most important river of the

province A province is almost always an administrative division within a country or sovereign state, state. The term derives from the ancient Roman ''Roman province, provincia'', which was the major territorial and administrative unit of the Roman Empire ...

Neuquén Neuquén (; arn, Nehuenken) is the capital city of the Argentine province of Neuquén and of the Confluencia Department, located in the east of the province. It occupies a strip of land west of the confluence of the Limay and Neuquén rivers w ...

in the

Argentine Argentines (mistakenly translated Argentineans in the past; in Spanish (masculine) or (feminine)) are people identified with the country of Argentina. This connection may be residential, legal, historical or cultural. For most Argentines, s ...

Patagonia Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and gl ...

, after the

Limay River The Limay River is an important river in the northwestern Argentine Patagonia (the region of Comahue). It originates at the eastern end of the Nahuel Huapi Lake and flows in a meandering path for about , collecting the waters of several tributari ...

. Rocks of the Neuquén Basin are fossiliferous, and the basin hosts what may become important fields of

tight oil Tight oil (also known as shale oil, shale-hosted oil or light tight oil, abbreviated LTO) is light crude oil contained in unconventional petroleum-bearing formations of low permeability, often shale or tight sandstone. Economic production from ...

and gas.

Overview

The river begins in the northwest of the province at an elevation of , to be fed by a number of streams through valleys of the lower

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

while advancing diagonally in southeast direction. Among these streams, some of them from draining of small lakes, are the Trocomán, Reñi Leuvü, Agrio and Nahueve. Further down, its main

tributaries A tributary, or affluent, is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drainage b ...

are the rivers Varvarco, and Agrio, who provides almost a third of the Neuquén flow. Along its way the river receives some sediments from volcanoes

Copahue Copahue () is a stratovolcano in the Andes on the border of Bío Bío Region, Chile and Neuquén Province, Argentina. There are nine volcanic craters along a line, the easternmost of which is historically the most active, and contains a 300&nbs ...

and

Domuyo The Domuyo Volcano is a stratovolcano located in the Argentine province of Neuquén. With a height of , it is the highest mountain in Patagonia and is sometimes called the "Roof of Patagonia" (''"El Techo de la Patagonia"'' in Spanish). The volc ...

that might sometimes affect the clarity of the otherwise clean waters. After meeting the Agrio, the Neuquén river has no natural lakes that could regulate its flow, which results in sharp raises of level during

thawing Melting, or fusion, is a physical process that results in the phase transition of a substance from a solid to a liquid. This occurs when the internal energy of the solid increases, typically by the application of heat or pressure, which ...

and rainy periods. A derivative channel towards the Pellegrini Lake in

Río Negro Province Río Negro (, ''Black River'') is a province of Argentina, located in northern Patagonia. Neighboring provinces are from the south clockwise Chubut, Neuquén, Mendoza, La Pampa and Buenos Aires. To the east lies the Atlantic Ocean. Its capit ...

has been built to compensate for abrupt changes in the flow, as well as the Cerros Colorados Complex, also used to generate

hydroelectricity Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other Renewabl ...

. The average flow of the river is of (measured at Paso de Indios), and its drainage basin covers about . At its mouth at , the Neuquén meets the

near the city of

, to form the Río Negro, which continues its way east towards the

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

. Although not as famous as other fishing rivers in Patagonia, the river is also visited by

fly fishing Fly fishing is an angling method that uses a light-weight lure—called an artificial fly—to catch fish. The fly is cast using a fly rod, reel, and specialized weighted line. The light weight requires casting techniques significantly diffe ...

and

spinning Spin or spinning most often refers to: * Spinning (textiles), the creation of yarn or thread by twisting fibers together, traditionally by hand spinning * Spin, the rotation of an object around a central axis * Spin (propaganda), an intentionally b ...

enthusiasts, as well as the two artificial lakes named Los Barreales and Mari Menuco, located by the river near the border with Río Negro Province. The main catch are

trout Trout are species of freshwater fish belonging to the genera '' Oncorhynchus'', ''Salmo'' and ''Salvelinus'', all of the subfamily Salmoninae of the family Salmonidae. The word ''trout'' is also used as part of the name of some non-salmoni ...

s and Patagonian '' pejerrey''.

Geology of the Neuquén Basin

In the satellite image, the deep reds of the Candeleros Formation, a sequence of sandstones formed roughly 90 to 100 million years ago in a braided river system, dominate the landscape. These rocks are flanked in some areas, especially near the river, by a green-yellow sequence of rocks that are part of the younger Hunical Formation, formed during drier times.

Paleontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

s have uncovered numerous fossils in the Candeleros rocks, including ancient species of fish, frogs, snakes, turtles, small mammals, and several types of dinosaurs. The best known dinosaur found here is

Giganotosaurus carolinii ''Giganotosaurus'' ( ) is a genus of theropod dinosaur that lived in what is now Argentina, during the early Cenomanian age of the Late Cretaceous period, approximately 99.6 to 95 million years ago. The holotype specimen was discovered in th ...

, a carnivorous theropod thought to be larger and faster than

Tyrannosaurus rex ''Tyrannosaurus'' is a genus of large theropod dinosaur. The species ''Tyrannosaurus rex'' (''rex'' meaning "king" in Latin), often called ''T. rex'' or colloquially ''T-Rex'', is one of the best represented theropods. ''Tyrannosaurus'' live ...

.The Geologic Wonder of the Neuquén Basin
by NASA Earth Observatory, 2018 The recent discovery of a large deposit of

shale gas Shale gas is an unconventional natural gas that is found trapped within shale formations. Since the 1990s a combination of horizontal drilling and hydraulic fracturing has made large volumes of shale gas more economical to produce, and some a ...

and oil in the deeper Vaca Muerta formation has made the Neuquén Basin one of the few regions outside of the United States where companies are pursuing horizontal drilling and

hydraulic fracturing Fracking (also known as hydraulic fracturing, hydrofracturing, or hydrofracking) is a well stimulation technique involving the fracturing of bedrock formations by a pressurized liquid. The process involves the high-pressure injection of "frack ...

References and external links

Subsecretaría de Recursos Hídricos
— "Cartografía Hídrica de Neuquén" - pdf
Monografias.com
— "Región patagónica"
Ministry of Environment
— Hydrological basins of Argentina. {{DEFAULTSORT:Neuquen River Rivers of Neuquén Province Rivers of Río Negro Province Rivers of Argentina