The Serra dos Órgãos is the name of the region of the Serra do Mar in the central part of the state of Rio de Janeiro. It covers an area of 20,024 hectares (49,480 acres).[1] The range is an escarpment on the northern edge of the Guanabara Graben between the cities of Petrópolis and Teresópolis.[2] The name comes from perceived resemblance of the vertical rock formations created by erosion to the tubes of organs used in Portuguese churches at the time.[3]
Topologyedit
Along the escarpment the altitude ranges from near sea level in the coastal plain to 2,260 metres (7,410 ft) above sea level 4 kilometres (2.5 mi) further inland.[2] The average elevation is 1,100 metres (3,600 ft) above sea level.[3] The Dedo de Deus (God's Finger) and Escalavrado, at 1,692 metres (5,551 ft) and 1,490 metres (4,890 ft) and the nearby peaks with steep rock walls are dramatic features that can be seen on a clear day from Rio de Janeiro, which is 50 kilometres (31 mi) distant.[2] The highest point is Pedra do Sino (Bell Rock) at 2,263 metres (7,425 ft).[1]
A north west fracture is exposed at the plateau's rock surfaces, which defines the direction of the ridges and valleys along the escarpment. One of these ridges contains several granite peaks including God's Finger. North east vertical fractures, spaced regularly about every 500 metres (1,600 ft), cut the north west structures at right angles. Erosion along these fractures has isolated the massive rock blocks.[4] The valleys have well-preserved deposits of debris that has fallen from the rock walls.[5] In November 1981 a period of intense rain triggered hundreds of shallow landslides and flows of debris that blocked the BR-116 highway and killed about 20 people.[6]
Geologyedit
The mountains consist of granitic gneisses of the Neoproterozoic era. The region is structurally complex with considerable faulting combined with erosion.[1] The ridge containing the God's Finger and other towers is unusual in being sustained by a thick dike of Cambrian granite that is more resistant to erosion than the surrounding Neoproterozoic orthogneisses.[7] Formation of the rocks may have occurred around 620 million years ago.[1]
Migon, Piotr (2010-01-22), Geomorphological Landscapes of the World, Springer Science & Business Media, ISBN978-90-481-3055-9, retrieved 2016-06-09
Vieira, Bianca Carvalho; Salgado, André; Santos, Leonardo (2015-03-05), Landscapes and Landforms of Brazil, Springer, ISBN978-94-017-8023-0, retrieved 2016-06-09
January 01, 1970
serra, Órgãos, dedo, deus, redirects, here, stack, gran, canaria, dedo, dios, organ, range, mountain, range, state, janeiro, brazil, contains, national, park, finger, from, teresópolishighest, pointelevation2, coordinates22, 463576, 030613, 463576, 030613geogr. Dedo de Deus redirects here For the sea stack off Gran Canaria see El Dedo de Dios The Serra dos orgaos Organ Range is a mountain range in the state of Rio de Janeiro Brazil It contains the Serra dos orgaos National Park Serra dos orgaosFinger of God from TeresopolisHighest pointElevation2 263 m 7 425 ft Coordinates22 27 49 S 43 01 50 W 22 463576 S 43 030613 W 22 463576 43 030613GeographySerra dos orgaos Contents 1 Location 2 Topology 3 Geology 4 See also 5 Notes 6 SourcesLocation editThe Serra dos orgaos is the name of the region of the Serra do Mar in the central part of the state of Rio de Janeiro It covers an area of 20 024 hectares 49 480 acres 1 The range is an escarpment on the northern edge of the Guanabara Graben between the cities of Petropolis and Teresopolis 2 The name comes from perceived resemblance of the vertical rock formations created by erosion to the tubes of organs used in Portuguese churches at the time 3 Topology editAlong the escarpment the altitude ranges from near sea level in the coastal plain to 2 260 metres 7 410 ft above sea level 4 kilometres 2 5 mi further inland 2 The average elevation is 1 100 metres 3 600 ft above sea level 3 The Dedo de Deus God s Finger and Escalavrado at 1 692 metres 5 551 ft and 1 490 metres 4 890 ft and the nearby peaks with steep rock walls are dramatic features that can be seen on a clear day from Rio de Janeiro which is 50 kilometres 31 mi distant 2 The highest point is Pedra do Sino Bell Rock at 2 263 metres 7 425 ft 1 A north west fracture is exposed at the plateau s rock surfaces which defines the direction of the ridges and valleys along the escarpment One of these ridges contains several granite peaks including God s Finger North east vertical fractures spaced regularly about every 500 metres 1 600 ft cut the north west structures at right angles Erosion along these fractures has isolated the massive rock blocks 4 The valleys have well preserved deposits of debris that has fallen from the rock walls 5 In November 1981 a period of intense rain triggered hundreds of shallow landslides and flows of debris that blocked the BR 116 highway and killed about 20 people 6 Geology editThe mountains consist of granitic gneisses of the Neoproterozoic era The region is structurally complex with considerable faulting combined with erosion 1 The ridge containing the God s Finger and other towers is unusual in being sustained by a thick dike of Cambrian granite that is more resistant to erosion than the surrounding Neoproterozoic orthogneisses 7 Formation of the rocks may have occurred around 620 million years ago 1 nbsp Serra dos Orgaos during the 1820s Painting by Johann Moritz Rugendas nbsp Serra dos orgaos as seen from Teresopolis 1885 Oil on canvas by Georg Grimm nbsp Peaks from left to right Escalavrado Dedo de Nossa Senhora Dedo de Deus Cabeca de Peixe and Santo Antonio nbsp Serra dos orgaos in the background as seen from the city of Rio de Janeiro nbsp SunriseSee also editPedra da Gavea Sugarloaf Mountain and Urca Hill Natural MonumentNotes edit a b c d Geologia Chico Mendes a b c Migon 2010 p 95 a b Vieira Salgado amp Santos 2015 p 294 Migon 2010 p 96 Migon 2010 p 97 Migon 2010 p 96 98 Migon 2010 p 96 97 Sources editGeologia in Portuguese Chico Mendes Institute for Biodiversity Conservation retrieved 2016 06 09 Migon Piotr 2010 01 22 Geomorphological Landscapes of the World Springer Science amp Business Media ISBN 978 90 481 3055 9 retrieved 2016 06 09 Vieira Bianca Carvalho Salgado Andre Santos Leonardo 2015 03 05 Landscapes and Landforms of Brazil Springer ISBN 978 94 017 8023 0 retrieved 2016 06 09 Retrieved from https en wikipedia org w index php title Serra dos orgaos amp oldid 1208204858, wikipedia, wiki, book, books, library,
