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Age, source, and regional stratigraphy of the Roraima Supergroup and Roraima-like outliers in northern South America based on U-Pb geochronology

2003; Geological Society of America; Volume: 115; Linguagem: Inglês

10.1130/0016-7606(2003)115 2.0.co;2

1943-2674

João Orestes Schneider Santos, Paul Edwin Potter, Nélson Joaquim Reis, Léo Afrâneo Hartmann, Ian R. Fletcher, Neal J. McNaughton,

earthquake and tectonic studies

Research Article| March 01, 2003 Age, source, and regional stratigraphy of the Roraima Supergroup and Roraima-like outliers in northern South America based on U-Pb geochronology João Orestes Schneider Santos; João Orestes Schneider Santos 1Departamento de Geologia, Companhia de Pesquisa de Recursos Minerais (CPRM), Avenida André Araújo 2160, Manaus, Amazonas, 69060-001, Brazil, and Universidade Federal do Rio Grande do Sul (UFRGS), Avenida Bento Gonçalves 9500, Porto Alegre, Rio Grande do Sul, 91500-000, Brazil Search for other works by this author on: GSW Google Scholar Paul Edwin Potter; Paul Edwin Potter 2Geology Department, University of Cincinnati, Cincinnati, Ohio 45221-0013, USA Search for other works by this author on: GSW Google Scholar Nélson Joaquim Reis; Nélson Joaquim Reis 3Superintendência Regional de Manaus, Companhia de Pesquisa de Recursos Minerais (CPRM), Avenida André Araújo 2160, Manaus, Amazonas, 69060-001, Brazil Search for other works by this author on: GSW Google Scholar Léo Afraneo Hartmann; Léo Afraneo Hartmann 4Instituto de Geociências, Universidade Federal do Rio Grande do Sul (UFRGS), Avenida Bento Gonçalves 9500, Porto Alegre, Rio Grande do Sul, 91500-000, Brazil Search for other works by this author on: GSW Google Scholar Ian Robert Fletcher; Ian Robert Fletcher 5Centre for Global Metallogeny, University of Western Australia, Nedlands 6907, Australia Search for other works by this author on: GSW Google Scholar Neal J. McNaughton Neal J. McNaughton 5Centre for Global Metallogeny, University of Western Australia, Nedlands 6907, Australia Search for other works by this author on: GSW Google Scholar Author and Article Information João Orestes Schneider Santos 1Departamento de Geologia, Companhia de Pesquisa de Recursos Minerais (CPRM), Avenida André Araújo 2160, Manaus, Amazonas, 69060-001, Brazil, and Universidade Federal do Rio Grande do Sul (UFRGS), Avenida Bento Gonçalves 9500, Porto Alegre, Rio Grande do Sul, 91500-000, Brazil Paul Edwin Potter 2Geology Department, University of Cincinnati, Cincinnati, Ohio 45221-0013, USA Nélson Joaquim Reis 3Superintendência Regional de Manaus, Companhia de Pesquisa de Recursos Minerais (CPRM), Avenida André Araújo 2160, Manaus, Amazonas, 69060-001, Brazil Léo Afraneo Hartmann 4Instituto de Geociências, Universidade Federal do Rio Grande do Sul (UFRGS), Avenida Bento Gonçalves 9500, Porto Alegre, Rio Grande do Sul, 91500-000, Brazil Ian Robert Fletcher 5Centre for Global Metallogeny, University of Western Australia, Nedlands 6907, Australia Neal J. McNaughton 5Centre for Global Metallogeny, University of Western Australia, Nedlands 6907, Australia Publisher: Geological Society of America Received: 31 Jul 2001 Revision Received: 28 Mar 2002 Accepted: 28 Mar 2002 First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2003) 115 (3): 331–348. https://doi.org/10.1130/0016-7606(2003)115 2.0.CO;2 Article history Received: 31 Jul 2001 Revision Received: 28 Mar 2002 Accepted: 28 Mar 2002 First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation João Orestes Schneider Santos, Paul Edwin Potter, Nélson Joaquim Reis, Léo Afraneo Hartmann, Ian Robert Fletcher, Neal J. McNaughton; Age, source, and regional stratigraphy of the Roraima Supergroup and Roraima-like outliers in northern South America based on U-Pb geochronology. GSA Bulletin 2003;; 115 (3): 331–348. doi: https://doi.org/10.1130/0016-7606(2003)115 2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract 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. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.