The Trans Brazilian Lineament (TBL), or Transbrasiliano Lineament, is a major shear zone that developed in the Precambrian period, and that has been reactivated several times since then, mostly recently during the Mesozoic. Movement along the shear zone helps explain how the South American continent could have fitted tightly to the African continent before the breakup of Gondwana.[1]
The TBL was formed when the Goiás Ocean, lying between the Amazonian craton and the Congo / Sao Francisco craton, was closed during the formation of West Gondwana around 600 million years ago.[2] The lineament extends from the northeast coast of Brazil in a southwesterly direction through Paraguay and into Argentina, where it is dissipated in the Salado and Colorado extension basins.[1]
The Trans-Saharan Belt (TSB), running from Algeria to Benin, was created in the same period. It marks the line where the Pharusian Ocean, linked to the Goiás Ocean, was closed as the West African craton collided with the Saharan Metacraton.[2] The TSB includes the Hoggar belt, which splays into the Kandi fault zone in Benin, corresponding to the Sobral fault at the north of the TBL. Given the correspondence of faults, which is widely accepted, the TBL and TBS form perhaps the longest coherent shear zone on the Earth.[3]
Gondwana breakupedit
Towards the north of the lineament in Brazil, a series of splay faults show where the crust has extended, and these faults match corresponding faults in Africa. Thus the Pernambuco fault in Brazil matches the Foumban fault zone in Cameroon, and other Brazilian faults match the Benue Trough in Nigeria. The extension caused by these splay faults causes a poor fit between South America and Africa around the Niger Delta region.[1] However, after allowing for a sinistral shear movement of about 100 km of the crust to the east of the TBL, there is an excellent fit between South America and Africa both to the south and the west of the Niger Delta.[4]
^ abcJ D Fairhead, Nasreddine Bournas and M Chaker Raddadi (2007). (PDF). SEG. Archived from the original (PDF) on 2011-07-11. Retrieved 2011-01-30.
^ abRobert D. Hatcher (2007). 4-D framework of continental crust. Geological Society of America. p. 316. ISBN978-0-8137-1200-0.
^Attoh, K.; Brown, L. D. (2008). "The Neoproterozoic Trans-Saharan/Trans-Brasiliano shear zones: Suggested Tibetan Analogs". AGU Spring Meeting Abstracts. 2008. American Geophysical Union: S51A–04. Bibcode:2008AGUSM.S51A..04A.
^Gillian R. Foulger (2005). Plates, plumes, and paradigms. Geological Society of America. p. 545. ISBN0-8137-2388-4.
April 14, 2024
trans, brazilian, lineament, transbrasiliano, lineament, major, shear, zone, that, developed, precambrian, period, that, been, reactivated, several, times, since, then, mostly, recently, during, mesozoic, movement, along, shear, zone, helps, explain, south, am. The Trans Brazilian Lineament TBL or Transbrasiliano Lineament is a major shear zone that developed in the Precambrian period and that has been reactivated several times since then mostly recently during the Mesozoic Movement along the shear zone helps explain how the South American continent could have fitted tightly to the African continent before the breakup of Gondwana 1 Contents 1 Formation and location 2 Gondwana breakup 3 See also 4 ReferencesFormation and location editThe TBL was formed when the Goias Ocean lying between the Amazonian craton and the Congo Sao Francisco craton was closed during the formation of West Gondwana around 600 million years ago 2 The lineament extends from the northeast coast of Brazil in a southwesterly direction through Paraguay and into Argentina where it is dissipated in the Salado and Colorado extension basins 1 The Trans Saharan Belt TSB running from Algeria to Benin was created in the same period It marks the line where the Pharusian Ocean linked to the Goias Ocean was closed as the West African craton collided with the Saharan Metacraton 2 The TSB includes the Hoggar belt which splays into the Kandi fault zone in Benin corresponding to the Sobral fault at the north of the TBL Given the correspondence of faults which is widely accepted the TBL and TBS form perhaps the longest coherent shear zone on the Earth 3 Gondwana breakup editTowards the north of the lineament in Brazil a series of splay faults show where the crust has extended and these faults match corresponding faults in Africa Thus the Pernambuco fault in Brazil matches the Foumban fault zone in Cameroon and other Brazilian faults match the Benue Trough in Nigeria The extension caused by these splay faults causes a poor fit between South America and Africa around the Niger Delta region 1 However after allowing for a sinistral shear movement of about 100 km of the crust to the east of the TBL there is an excellent fit between South America and Africa both to the south and the west of the Niger Delta 4 See also editBrasiliano orogenyReferences edit a b c J D Fairhead Nasreddine Bournas and M Chaker Raddadi 2007 The Role of Gravity and Aeromagnetic Data in Mapping Mega Gondwana Crustal Lineaments the Argentina Brazil Algeria ABA Lineament PDF SEG Archived from the original PDF on 2011 07 11 Retrieved 2011 01 30 a b Robert D Hatcher 2007 4 D framework of continental crust Geological Society of America p 316 ISBN 978 0 8137 1200 0 Attoh K Brown L D 2008 The Neoproterozoic Trans Saharan Trans Brasiliano shear zones Suggested Tibetan Analogs AGU Spring Meeting Abstracts 2008 American Geophysical Union S51A 04 Bibcode 2008AGUSM S51A 04A Gillian R Foulger 2005 Plates plumes and paradigms Geological Society of America p 545 ISBN 0 8137 2388 4 Retrieved from https en wikipedia org w index php title Trans Brazilian Lineament amp oldid 1032659602, wikipedia, wiki, book, books, library,
