Basaltic andesite is a volcanic rock containing about 55% silica. It is distinct from basalt and andesite in having a different percentage of silica content. Minerals in basaltic andesite include olivine, augite and plagioclase.Basaltic andesite can be found in volcanoes around the world, including in Central America and the Andes of South America.
Antofagasta de la Sierra is a volcanic field in Argentina. The main type of volcanic edifice in the area are scoria cones, it is formed by the La Laguna, Jote and Alumbrera volcanoes. The first and last of these form a sub-group which is better researched. Various dating methods have yielded ages from several million to several hundred thousand years ago, but some vents appear to be of Holocene age.
The andesite line is the most significant regional geologic distinction in the Pacific Ocean basin. It separates the mafic basaltic volcanic rocks of the Central Pacific Basin from the partially submerged continental areas of more felsic andesitic volcanic rock on its margins. The andesite line parallels the subduction zones and deep oceanic trenches around the Pacific basin. It is the surface expression of melting within and above the plunging subducting slab. It follows the western edge of the islands off California and passes south of the Aleutian Arc, along the eastern edge of the Kamchatka Peninsula, the Kuril Islands, Japan, the Mariana Islands, Yap, Palau, the Solomon Islands, Fiji, Tonga, and New Zealand's North Island. The dissimilarity continues northeastward along the western edge of the Andes mountains of South America to Mexico, returning then to the islands off California. Indonesia, the Philippines, Japan, New Guinea, and New Zealand lie outside the andesite line.
Monte Pissis is an extinct volcano on the border of La Rioja and Catamarca provinces, Argentina, 25 km (16 mi) from the Chilean border. The mountain is the third-highest in the Western Hemisphere, and is located about 550 km (340 mi) north of Aconcagua. Monte Pissis is named after Pedro José Amadeo Pissis, a French geologist who worked for the Chilean government. Due to its location in the Atacama Desert, the mountain has very dry conditions but there is an extensive glacier
Incahuasi is a volcanic mountain in the Andes of South America. It lies on the border of the Argentine province of Catamarca, and the Atacama Region of Chile. Incahuasi has a summit elevation of 6,621 metres (21,722 ft) above sea level.
Nevado San Francisco, or Cerro San Francisco, is a stratovolcano on the border between Argentina and Chile, located just southeast of San Francisco Pass. It is considered extinct and is one of the several 6,000 m (19,700 ft) peaks in the area, of which the chief is the Ojos del Salado.
Los Patos is a mountain in the Andes mountain range of South America. The peak is located on the international border of the Catamarca Province of Argentina and the Atacama Region of Chile. It has a summit elevation of 6,239 metres (20,469 ft).
Neuquén Basin is a sedimentary basin covering most of Neuquén Province in Argentina. The basin originated in the Jurassic and developed through alternating continental and marine conditions well into the Tertiary. The basin bounds to the west with the Andean Volcanic Belt, to the southeast with the North Patagonian Massif and to the northeast with the San Rafael Block and to the east with the Sierra Pintada System. The basin covers an area of approximately 120,000 square kilometres (46,000 sq mi). One age of the SALMA classification, the Colloncuran, is defined in the basin, based on the Collón Curá Formation, named after the Collón Curá River, a tributary of the Limay River.
The Andean orogeny is an ongoing process of orogeny that began in the Early Jurassic and is responsible for the rise of the Andes mountains. The orogeny is driven by a reactivation of a long-lived subduction system along the western margin of South America. On a continental scale the Cretaceous and Oligocene were periods of re-arrangements in the orogeny. Locally the details of the nature of the orogeny varies depending on the segment and the geological period considered.
Lanín is an ice-clad, cone-shaped stratovolcano on the border of Argentina and Chile. It forms part of two national parks: Lanín in Argentina and Villarrica in Chile. It is a symbol of the Argentine province of Neuquén, being part of its flag and its anthem. Although the date of its last eruption is not known, it is estimated to have occurred within the last 10,000 years. Following the 1906 Valparaíso earthquake a local newspaper reported the volcano to have erupted, but a work published in 1917 by Karl Sapper disputed this.
El Barco Lake is a lake in the Bío Bío Region of Chile, near the Callaqui stratovolcano.
Pablo Groeber was a German geologist known for his contributions to the understanding of the geology of Tien Shan in Central Asia and the Andes of Nequén and Mendoza Province in Argentina.
Jotabeche is a Miocene-Pliocene caldera in the Atacama Region of Chile. It is part of the volcanic Andes, more specifically of the extreme southern end of the Central Volcanic Zone (CVZ). This sector of the Andean Volcanic Belt contains about 44 volcanic centres and numerous more minor volcanic systems, as well as some caldera and ignimbrite systems. Jotabeche is located in a now inactive segment of the CVZ, the Maricunga Belt.
Leon Muerto is a 4,799 metres (15,745 ft) high volcano in Chile.
Ojos de Maricunga is a volcano in the Maricunga Belt of Chile, in the Cordillera Domeyko.(Muñoz 1894, p. 51)
Pairique volcanic complex is a volcanic complex in the Jujuy Province, Argentina.
Antofalla is a Miocene-Pliocene volcano in Argentina's Catamarca Province. It is part of the volcanic segment of the Andes in Argentina, and it is considered to be part of the Central Volcanic Zone, one of the volcanic zones of the Andes. Antofalla forms a group of volcanoes that are aligned on and behind the main volcanic arc. Antofalla itself is a remote volcano.
The geology of Peru includes ancient Proterozoic rocks, deformed by the Grenville orogeny, Paleozoic and Mesozoic volcanic and sedimentary rocks and numerous basins and the Andes Mountains formed in the Cenozoic.
The geology of Panama includes the complex tectonic interplay between the Pacific, Cocos and Nazca plates, the Caribbean Plate and the Panama Microplate.
The geology of Costa Rica is part of the Panama Microplate, which is slowly moving north relative to the stable Caribbean Plate.
Suzanne Mahlburg Kay is the William & Katherine Snee Professor of Geological Sciences at Cornell University. She studies the origin and evolution of the continental crust. She is a Fellow of the Geological Society of America, the American Geophysical Union and the Mineralogical Society of America.
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