Question: Which geologic formation is found in the northern edge of Patagonia?

full_context: Document 1: Cuyo (Argentina): Cuyo is the name given to the wine-producing, mountainous area of central-west Argentina. Historically it comprised the provinces of San Juan, San Luis and Mendoza and was influenced by Chile. The modern term New Cuyo indicates both Cuyo proper and the province of La Rioja. New Cuyo is a political and economic macroregion, but culturally La Rioja is part of the North-West rather than of Cuyo.
Document 2: Chubut River: The Chubut River (Spanish: "Río Chubut" , Welsh: "Afon Camwy" ) is located in the Patagonia region of southern Argentina. Its name comes from the Tehuelche word "chupat", which means "transparent". The Argentine Chubut Province, through which the river flows, is named after it. Welsh settlers called the river "Afon Camwy," meaning "twisting river" in English.
Document 3: Patagonia: Patagonia (] ) is a sparsely populated region located at the southern end of South America, shared by Argentina and Chile. The region comprises the southern section of the Andes mountains as well as the deserts, pampas and grasslands east of this southern portion of the Andes. Patagonia has two coasts: western facing the Pacific Ocean and eastern facing the Atlantic Ocean.
Document 4: Muyelensaurus: Muyelensaurus is a genus of titanosaurian sauropod dinosaur from the Late Cretaceous of Argentina. It was more slender than other titanosaurs. Fossils have been recovered from the Portezuelo Formation in the Neuquén province of Patagonia. The type species is "M. pecheni". The name "Muyelensaurus" first appeared in a 2007 paper by Argentine paleontologists Jorge Calvo of the Universidad Nacional del Comahue and Bernardo González Riga of the Laboratorio de Paleovertebrados, and Brazilian paleontologist Juan Porfiri of the Universidade Federal do Rio de Janeiro.
Document 5: Argentina: Argentina ( ; ] ), officially the Argentine Republic (Spanish: "República Argentina" ), is a federal republic in the southern portion of South America. Sharing the bulk of the Southern Cone with its neighbor Chile to the west, the country is also bordered by Bolivia and Paraguay to the north, Brazil to the northeast, Uruguay and the South Atlantic Ocean to the east, and the Drake Passage to the south. With a mainland area of 2780400 km2 , Argentina is the eighth-largest country in the world, the second largest in Latin America, and the largest Spanish-speaking one. The country is subdivided into twenty-three provinces (Spanish: "provincias" , singular "provincia") and one autonomous city ("ciudad autónoma"), Buenos Aires, which is the federal capital of the nation (Spanish: "Capital Federal" ) as decided by Congress.
Document 6: Sierra Bayas Group: Sierra Bayas Group is a group of Neoproterozoic-aged sedimentary rock formations in Buenos Aires Province, Argentina. The group crops out in the central and northwestern parts of the Tandilia System, a chain of hills made up by of ancient rocks. The nearby Cerro Negro Formation aside, Sierra Bayas Group contains the oldest sedimentary formations in Argentina that have not been subject to significant metamorphism or deformation. It was formerly grouped together with Cerro Negro Formation and the Ordivician Balcarce Formation into La Tinta Group. Sierra Bayas Group and the former La Tinta Group have equivalents in Southern Africa, in La Tinta Group in particular is considered equivalent to the Nama Group found in Namibia and South Africa. From top to bottom Sierra Bayas Group is subdivided Loma Negra, Olavarría, Cerro Largo, Colombo and Villa Mónica formations. Sierra Bayas Group has a thickness of 175 meters and the age its rocks range from Tonian to Ediacaran.
Document 7: Pari Aike Formation: The Pari Aike Formation is a Late Cretaceous geologic formation of Cenomanian (formerly believed to be Maastrichtian) age in southern Patagonia, Argentina. The giant titanosaur "Puertasaurus", the megaraptoran "Orkoraptor", and the ornithopod "Talenkauen" have been recovered from the formation alongside turtles and crocodiles.
Document 8: Eramosa: The term was first used for a stratigraphic unit by Williams (1915) who named the Eramosa Member (of the Lockport Formation) for the bituminous dolomites exposed below the Guelph Formation along the Eramosa River, northeast of Guelph, Ontario. No detailed description of the type section has ever been published, and the status of the unit has been subject to many different interpretations. Until recently, the Eramosa in Ontario was regarded as the highest Member of the Lockport Formation, with gradational contacts with the Goat Island Member (below) and the Guelph Formation (above). In 1995, the US Geological Survey proposed a revised stratigraphy based on studies in the Niagara region. It extended the Lockport to Group status and included, from base to top, the Gasport, Goat Island, Eramosa, and Guelph as Formations within the Lockport Group. In a “reference section” in the Niagara River Gorge, the Eramosa was divided into six “units” recognized throughout the Niagara region, but a shaley lower unit previously named for the Hamilton area (the Vinemount Member) was transferred to the Goat Island Formation. Brunton (2009) has proposed a revision for Ontario which restores the Vinemount Member to the Eramosa and recognizes two other members.
Document 9: Bajo de la Carpa Formation: The Bajo de la Carpa Formation is a geologic formation that outcrops in Patagonia, in the provinces of Río Negro and Neuquén, Argentina. It is the first of two formations belonging to the Río Colorado Subgroup within the Neuquén Group. Formerly that subgroup was treated as a formation, and the Bajo de la Carpa Formation was known as the Bajo de la Carpa Member.
Document 10: La Rioja Province, Argentina: La Rioja (] ) is one of the provinces of Argentina and is located in the west of the country. Neighboring provinces are from the north clockwise Catamarca, Córdoba, San Luis and San Juan. The dinosaur "Riojasaurus" is named after the province.
Document 11: Neuquensuchus: Neuquensuchus (meaning "Neuquén crocodile", referring to the city) is an extinct genus of notosuchian crocodyliform from the Santonian-age Upper Cretaceous Bajo de la Carpa Formation of Neuquén Province, Argentina. The known remains were discovered on the campus of Universidad Nacional del Comahue in the city of Neuquén. "Neuquensuchus" was named by Lucas E. Fiorelli and Jorge O. Calvo in a publication dated to 2007, but which became available in 2008. The type species is "N. universitas", in recognition of its discovery locality. Unlike the great majority of crocodyliforms, its shin was longer than its thigh, suggesting it had some running ability.
Document 12: Matanza River: The Matanza River is known by several names, including, in Spanish, Río de la Matanza ("the slaughter river" in English), Río Matanza ("slaughter river"), Río Mataderos ("slaughterhouses river"), Río de la Manzana ("the apple river") or simply Riachuelo ("little river" or "brook"). It is a 64 km stream in Argentina that originates in the Buenos Aires Province and defines the southern boundary of the Buenos Aires federal district. It empties into the Río de la Plata between Tandanor and Dock Sud. The La Boca neighbourhood and the Boca Juniors football club are located near the Riachuelo's mouth. The Spanish word "boca" means "mouth".
Document 13: Chubut Province: Chubut (Welsh: "Talaith Chubut" ; Spanish: "Provincia del Chubut" ] ) is a province in southern Argentina, situated between the 42nd parallel south (the border with Río Negro Province), the 46th parallel south (bordering Santa Cruz Province), the Andes range to the west, and the Atlantic ocean to the east. The province's name derives from the Tehuelche word "chupat", meaning "transparent," their description of the Chubut River.
Document 14: Portezuelo Formation: The Portezuelo Formation is a geologic formation outcropping in the Mendoza, Río Negro and Neuquén provinces of Argentina. It is the fourth-oldest formation in the Neuquén Group and the older of the two formations in the Río Neuquén Subgroup. Formerly, that subgroup was treated as a formation, and the Portezuelo Formation was known as the Portezuelo Member.
Document 15: Río Negro Province: Río Negro (] , "Black River") is a province of Argentina, located at the northern edge of Patagonia. Neighboring provinces are from the south clockwise Chubut, Neuquén, Mendoza, La Pampa and Buenos Aires. To the east lies the Atlantic Ocean.
ground_truth: Portezuelo Formation