The North Patagonian Massif or Somún Cura Massif ( Spanish: ''Macizo Norpatagónico'', ''Macizo Nordpatagónico'' or ''Macizo de Somún Cura'') is a massif in northern Patagonia located in the Argentine provinces of Río Negro and

Chubut Chubut may refer to: * Chubut Province, Argentina * Chubut River in the Chubut Province * Chubut steamer duck The Chubut steamer duck or white-headed flightless steamer duck (''Tachyeres leucocephalus'') is a flightless duck endemic to Argenti ...

. The massif is a

plateau In geology and physical geography, a plateau (; ; ), also called a high plain or a tableland, is an area of a highland consisting of flat terrain that is raised sharply above the surrounding area on at least one side. Often one or more sides ha ...

surrounded by

sedimentary basin Sedimentary basins are region-scale depressions of the Earth's crust where subsidence has occurred and a thick sequence of sediments have accumulated to form a large three-dimensional body of sedimentary rock. They form when long-term subsidence ...

s. The North Patagonian Massif covers an area of approximately . The massif rises above the surrounding topography reaching a maximum of above sea level. Compared to neighboring areas, the North Patagonian Massif has thicker continental crust.

Stratigraphy

The massif consists of a

basement A basement or cellar is one or more floors of a building that are completely or partly below the ground floor. It generally is used as a utility space for a building, where such items as the furnace, water heater, breaker panel or fuse box, ...

formed by Cambro- Ordovician rocks, overlain by the Middle Silurian Sierra Grande Formation. The early

Paleozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ' ...

section is covered by metamorphic and igneous complexes; the

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ...

Pailemán and Navarrete Plutonic Complexes,González et al., 2014, p.175 and the unconformably overlying

Early Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Early ...

Middle Jurassic The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations co ...

Marifil Volcanic Complex. The Marifil Complex is separated from the Paleozoic sequence by the Enjambre Dikes, dated to the

Late Triassic The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch ...

with ages varying between 221 ± 12 and 207 ± 11 Ma.González et al., 2014, p.176 The Cenozoic cover of the western belt of the massif comprises the

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

Ventana and

Ñirihuau Formation Ñirihuau is a village and municipality in Río Negro Province in Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an are ...

s in the north and the Middle to Late Miocene

Ñorquincó Formation Ñorquincó is a city in Ñorquincó Department, in southwest Río Negro Province, Argentina. With a population of 444, it had a decline of 12.7% after the 509 in the previous census. The name comes from the Mapudungun language, meaning ''Water P ...

in the south. The eastern belt of the North Patagonian Massif contains the Miocene (

Colloncuran The Colloncuran ( es, Colloncurense) age is a period of geologic time (15.5–13.8 Ma) within the Middle Miocene epoch of the Neogene, used more specifically within the SALMA classification in South America. It follows the Friasian and precedes ...

) Collón Cura Formation, the Miocene

La Pava Formation LA most frequently refers to Los Angeles, the second largest city in the United States. La, LA, or L.A. may also refer to: Arts and entertainment Music * La (musical note), or A, the sixth note * "L.A.", a song by Elliott Smith on ''Figure ...

,Dalla Salda & Franzese, 1987, p.7 and the Miocene Chimehuín Formation in the northern part of the eastern belt.Dalla Salda & Franzese, 1987, p.8

References

Bibliography

* * {{Authority control Landforms of Chubut Province Landforms of Río Negro Province Geology of Chubut Province Geology of Río Negro Province Plateaus of Argentina

Stratigraphy

See also

References

Bibliography