a prolonged history of emplacement. 41,000 ± 1,000 years ago, underlying the Los Morados lava flow. 37,000 ± 3,000 years ago, surface exposure dating, close to the Rio Grande River. 37,000 ± 1,000 years ago, La Planchada fallout deposit. 37,000 ± 2,000 years ago, northwestern side of the caldera. 28,000 ± 5,000 years ago, potassium-argon dating, lava flow on the westerly side. 26,000 ± 5,000 years ago, potassium-argon dating, close to the Rio Grande. 26,000 ± 2,000 years ago, potassium-argon dating, not the same as the 26,000 ± 5,000 flow. 26,000 ± 1,000 years ago, potassium-argon dating, rhyolitic lava flow in the La Calle group. 20,000 ± 7,000 years ago, north of the Payún Matrú caldera. 16,000 ± 1,000 years ago, underlying the Los Morados lava flow. 15,200 ± 900 years ago, potassium-argon dating, lava flow on the northwesterly-westerly side. 9,000 years ago, potassium-argon dating. 7,000 ± 1,000 years ago, potassium-argon dating, Escorial del Matru within the caldera. <7,000 years ago, potassium-argon dating, trachyandesitic lava flow in the western part of the field. 4,760 ± 450 years before present, thermoluminescence dating. 6,900 ± 650 years before present, thermoluminescence dating on the Guadalosos cones. 2,000 ± 2,000 years ago, surface exposure dating, young looking lava flow in the west. 1,470 years before present, thermoluminescence dating on Volcán Santa María although a much older age of 496,000 ± 110,000 years ago has also been given. 515 ± 50 years before present, thermoluminescence dating on Morado Sur cone. See also List of volcanoes in Argentina Explanatory notes References Citations General sources External links Payún Matru Volcanic Field, Argentina: Image of the Day at NASA's Earth Observatory Andean Volcanic Belt Mountains of Argentina Polygenetic shield volcanoes Quaternary South America Quaternary volcanoes Subduction volcanoes Volcanoes of Mendoza Province