Age, source and regional stratigraphy of the Roraima Supergroup and Roraima-like outliers in northern South America based on U-Pb gechronology
Autor(a) principal: | |
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Data de Publicação: | 2003 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional de Geociências - RIGEO |
Texto Completo: | https://rigeo.cprm.gov.br/handle/doc/507 |
Resumo: | New 207Pb/206Pb ion-microprobe dates from the basement underlying the Roraima Supergroup, from sandstones and tuffs within the supergroup, and from associated mafic intrusions establish new temporal framework for this major stratigraphic unit in northern South America. Zircons from the tuffs within the supergroup yield a Paleoproterozoic age of 1873 ± 3 Ma, Orosirian. The minimum age of the Roraima Supergroup was determined by U-Pb geochronology using baddeleyite and zircon from two mafic sills (Avanavero magmatism) and is 1782 ± 3 Ma. Zircons of some Roraima-like outliers indicate that they are post-Roraima in age and do not belong to the supergroup. This conclusion is supported by the unconformity between the Matauí and Uaimapué Formations present in the Pacaraima Plateau, which may represent a hiatus as long as 320 m.y. Thus, all the sandstones above the unconformity such as the Matauí Formation, as well as outliers such as the Serra Surucucus, Aracá, and Neblina units, do not belong to the supergroup. Rocks of the Roraima Supergroup and post-Roraima sandstones were deposited in two separate but overlapping basins, each 1,200,000 km2 in area. The Roraima Supergroup represents fill in a foreland basin that was derived mostly from the Trans-Amazon orogenic belt to the north and northeast, whereas the fill in the post-Roraima Neblina successor foreland basin was derived from both the Trans-Amazon and Tapajós-Parima orogenic belts to the east and northeast. Although most of both basins are largely flat lying or gently deformed, some of the westernmost outliers of the post-Roraima sandstones were deformed by the far-field effects of the Sunsás (Grenvillian) orogen at 1.33 Ga (Ar-Ar in muscovite). These results are based on U-Pb determinations of nine samples, Ar-Ar step-heating plateau age of one muscovite sample, and a complete review of many earlier Rb-Sr and K-Ar earlier dates |
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SANTOS, João Orestes SchneiderPOTTER, Paul EdwinREIS, Nelson JoaquimHARTMANN, Léo AfraneoFLETCHER, Ian RobertMcNAUGHTON, Neal J.2013-12-19T16:32:33Z2013-12-19T16:32:33Z2003SANTOS, João Orestes Schneider; POTTER, Paul Edwin; REIS, Nelson Joaquim; HARTMANN, Léo Afraneo; FLETCHER, Ian Robert; McNAUGHTON, Neal J. Age, source and regional stratigraphy of the Roraima Supergroup and Roraima-like outliers in northern South America based on U-Pb gechronology. Geological Society of America Bulletin, Boulder, Co, v.115, n.3, p.331-348, Boulder, Co.https://rigeo.cprm.gov.br/handle/doc/507New 207Pb/206Pb ion-microprobe dates from the basement underlying the Roraima Supergroup, from sandstones and tuffs within the supergroup, and from associated mafic intrusions establish new temporal framework for this major stratigraphic unit in northern South America. Zircons from the tuffs within the supergroup yield a Paleoproterozoic age of 1873 ± 3 Ma, Orosirian. The minimum age of the Roraima Supergroup was determined by U-Pb geochronology using baddeleyite and zircon from two mafic sills (Avanavero magmatism) and is 1782 ± 3 Ma. Zircons of some Roraima-like outliers indicate that they are post-Roraima in age and do not belong to the supergroup. This conclusion is supported by the unconformity between the Matauí and Uaimapué Formations present in the Pacaraima Plateau, which may represent a hiatus as long as 320 m.y. Thus, all the sandstones above the unconformity such as the Matauí Formation, as well as outliers such as the Serra Surucucus, Aracá, and Neblina units, do not belong to the supergroup. Rocks of the Roraima Supergroup and post-Roraima sandstones were deposited in two separate but overlapping basins, each 1,200,000 km2 in area. The Roraima Supergroup represents fill in a foreland basin that was derived mostly from the Trans-Amazon orogenic belt to the north and northeast, whereas the fill in the post-Roraima Neblina successor foreland basin was derived from both the Trans-Amazon and Tapajós-Parima orogenic belts to the east and northeast. Although most of both basins are largely flat lying or gently deformed, some of the westernmost outliers of the post-Roraima sandstones were deformed by the far-field effects of the Sunsás (Grenvillian) orogen at 1.33 Ga (Ar-Ar in muscovite). These results are based on U-Pb determinations of nine samples, Ar-Ar step-heating plateau age of one muscovite sample, and a complete review of many earlier Rb-Sr and K-Ar earlier datesGEOCRONOLOGIAESTRATIGRAFIAGEOLOGIA ESTRUTURALBRASILRORAIMAAge, source and regional stratigraphy of the Roraima Supergroup and Roraima-like outliers in northern South America based on U-Pb gechronologyinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleGeological Society of America BulletinwhiteA versão pdf do editor não pode ser utilizadainfo:eu-repo/semantics/openAccessBoulder, Coengreponame:Repositório Institucional de Geociências - RIGEOinstname:Companhia de Pesquisa de Recursos Minerais (CPRM)instacron:CPRMTEXTart_santos.pdf.txtart_santos.pdf.txtExtracted texttext/plain102313http://rigeo.cprm.gov.br/jspui/bitstream/doc/507/2/art_santos.pdf.txt9d121cac1cc561ca13a7134da28a1906MD52THUMBNAILart_santos.pdf.jpgart_santos.pdf.jpgGenerated Thumbnailimage/jpeg1767http://rigeo.cprm.gov.br/jspui/bitstream/doc/507/3/art_santos.pdf.jpg3bfe1e39c65c47830f683b60036bd707MD53ORIGINALart_santos.pdfart_santos.pdfproducao cientificaapplication/pdf3979330http://rigeo.cprm.gov.br/jspui/bitstream/doc/507/1/art_santos.pdff93ce8d836934888973256ce61bc41c7MD51doc/5072023-02-13 11:10:49.088oai:rigeo.sgb.gov.br:doc/507Repositório InstitucionalONGhttps://rigeo.sgb.gov.br/oai/request https://rigeo.cprm.gov.br/oai/requestrigeo@sgb.gov.bropendoar:2023-02-13T14:10:49Repositório Institucional de Geociências - RIGEO - Companhia de Pesquisa de Recursos Minerais (CPRM)false |
dc.title.none.fl_str_mv |
Age, source and regional stratigraphy of the Roraima Supergroup and Roraima-like outliers in northern South America based on U-Pb gechronology |
title |
Age, source and regional stratigraphy of the Roraima Supergroup and Roraima-like outliers in northern South America based on U-Pb gechronology |
spellingShingle |
Age, source and regional stratigraphy of the Roraima Supergroup and Roraima-like outliers in northern South America based on U-Pb gechronology SANTOS, João Orestes Schneider GEOCRONOLOGIA ESTRATIGRAFIA GEOLOGIA ESTRUTURAL BRASIL RORAIMA |
title_short |
Age, source and regional stratigraphy of the Roraima Supergroup and Roraima-like outliers in northern South America based on U-Pb gechronology |
title_full |
Age, source and regional stratigraphy of the Roraima Supergroup and Roraima-like outliers in northern South America based on U-Pb gechronology |
title_fullStr |
Age, source and regional stratigraphy of the Roraima Supergroup and Roraima-like outliers in northern South America based on U-Pb gechronology |
title_full_unstemmed |
Age, source and regional stratigraphy of the Roraima Supergroup and Roraima-like outliers in northern South America based on U-Pb gechronology |
title_sort |
Age, source and regional stratigraphy of the Roraima Supergroup and Roraima-like outliers in northern South America based on U-Pb gechronology |
author |
SANTOS, João Orestes Schneider |
author_facet |
SANTOS, João Orestes Schneider POTTER, Paul Edwin REIS, Nelson Joaquim HARTMANN, Léo Afraneo FLETCHER, Ian Robert McNAUGHTON, Neal J. |
author_role |
author |
author2 |
POTTER, Paul Edwin REIS, Nelson Joaquim HARTMANN, Léo Afraneo FLETCHER, Ian Robert McNAUGHTON, Neal J. |
author2_role |
author author author author author |
dc.contributor.author.fl_str_mv |
SANTOS, João Orestes Schneider POTTER, Paul Edwin REIS, Nelson Joaquim HARTMANN, Léo Afraneo FLETCHER, Ian Robert McNAUGHTON, Neal J. |
dc.subject.por.fl_str_mv |
GEOCRONOLOGIA ESTRATIGRAFIA GEOLOGIA ESTRUTURAL BRASIL RORAIMA |
topic |
GEOCRONOLOGIA ESTRATIGRAFIA GEOLOGIA ESTRUTURAL BRASIL RORAIMA |
description |
New 207Pb/206Pb ion-microprobe dates from the basement underlying the Roraima Supergroup, from sandstones and tuffs within the supergroup, and from associated mafic intrusions establish new temporal framework for this major stratigraphic unit in northern South America. Zircons from the tuffs within the supergroup yield a Paleoproterozoic age of 1873 ± 3 Ma, Orosirian. The minimum age of the Roraima Supergroup was determined by U-Pb geochronology using baddeleyite and zircon from two mafic sills (Avanavero magmatism) and is 1782 ± 3 Ma. Zircons of some Roraima-like outliers indicate that they are post-Roraima in age and do not belong to the supergroup. This conclusion is supported by the unconformity between the Matauí and Uaimapué Formations present in the Pacaraima Plateau, which may represent a hiatus as long as 320 m.y. Thus, all the sandstones above the unconformity such as the Matauí Formation, as well as outliers such as the Serra Surucucus, Aracá, and Neblina units, do not belong to the supergroup. Rocks of the Roraima Supergroup and post-Roraima sandstones were deposited in two separate but overlapping basins, each 1,200,000 km2 in area. The Roraima Supergroup represents fill in a foreland basin that was derived mostly from the Trans-Amazon orogenic belt to the north and northeast, whereas the fill in the post-Roraima Neblina successor foreland basin was derived from both the Trans-Amazon and Tapajós-Parima orogenic belts to the east and northeast. Although most of both basins are largely flat lying or gently deformed, some of the westernmost outliers of the post-Roraima sandstones were deformed by the far-field effects of the Sunsás (Grenvillian) orogen at 1.33 Ga (Ar-Ar in muscovite). These results are based on U-Pb determinations of nine samples, Ar-Ar step-heating plateau age of one muscovite sample, and a complete review of many earlier Rb-Sr and K-Ar earlier dates |
publishDate |
2003 |
dc.date.issued.fl_str_mv |
2003 |
dc.date.accessioned.fl_str_mv |
2013-12-19T16:32:33Z |
dc.date.available.fl_str_mv |
2013-12-19T16:32:33Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
SANTOS, João Orestes Schneider; POTTER, Paul Edwin; REIS, Nelson Joaquim; HARTMANN, Léo Afraneo; FLETCHER, Ian Robert; McNAUGHTON, Neal J. Age, source and regional stratigraphy of the Roraima Supergroup and Roraima-like outliers in northern South America based on U-Pb gechronology. Geological Society of America Bulletin, Boulder, Co, v.115, n.3, p.331-348, Boulder, Co. |
dc.identifier.uri.fl_str_mv |
https://rigeo.cprm.gov.br/handle/doc/507 |
identifier_str_mv |
SANTOS, João Orestes Schneider; POTTER, Paul Edwin; REIS, Nelson Joaquim; HARTMANN, Léo Afraneo; FLETCHER, Ian Robert; McNAUGHTON, Neal J. Age, source and regional stratigraphy of the Roraima Supergroup and Roraima-like outliers in northern South America based on U-Pb gechronology. Geological Society of America Bulletin, Boulder, Co, v.115, n.3, p.331-348, Boulder, Co. |
url |
https://rigeo.cprm.gov.br/handle/doc/507 |
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eng |
language |
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Geological Society of America Bulletin white A versão pdf do editor não pode ser utilizada info:eu-repo/semantics/openAccess |
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