Výsledky vyhledávání - "Lêda Maria Barreto Fraga"

Stratigraphy of the Roraima Supergroup along the Brazil-Guyana border in the Guiana shield, Northern Amazonian Craton - results of the Brazil-Guyana Geology and Geodiversity Mapping Project

Autor: Nelson Joaquim Reis, Deokumar Lachhman, Serge Nadeau, Maria Telma Lins Faraco, Randy Ault, Leandro Menezes Betiollo, Jimmy Reece, Lêda Maria Barreto Fraga

Publikováno v: Brazilian Journal of Geology v.47 n.1 2017
Brazilian Journal of Geology
Sociedade Brasileira de Geologia (SBGEO)
instacron:SBGEO
Brazilian Journal of Geology, Vol 47, Iss 1, Pp 43-57

The Geological and Geodiversity Mapping binational program along the Brazil-Guyana border zone allowed reviewing and integrating the stratigraphy and nomenclature of the Roraima Supergroup along the Pakaraima Sedimentary Block present in northeastern

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7f43df492edeb855a7363dfb4d9ffbba
https://doi.org/10.1590/2317-4889201720160139

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Guyana: the Lost Hadean crust of South America?

Autor: Nelson Joaquim Reis, Deokumar Lachhman, Jimmy Reece, Randy Ault, Maria Telma Lins Faraco, Lêda Maria Barreto Fraga, Serge Nadeau, Leandro Menezes Betiollo, Wei Chen

Publikováno v: Brazilian Journal of Geology. 43:601-606

A Hadean zircon xenocryst with a U-Pb zircon age of 4,219 ± 19 Ma, along with several zircon xenocrysts of Archean age (ca. 2,510 to 3,811 Ma) were found in a rock of the Paleoproterozoic Iwokrama Formation, which includes felsic volcanics and co-ma

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::84d47376af5b28c4618e908dc293ee45
https://doi.org/10.5327/z2317-48892013000400002

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Petrogenesis of the igneous Mucajaí AMG complex, northern Amazonian craton — Geochemical, U–Pb geochronological, and Nd–Hf–O isotopic constraints

Autor: Irmeli Mänttäri, Osmo Tapani Rämö, Roberto Dall'Agnol, Lêda Maria Barreto Fraga, Aku Heinonen, Tom Andersen

Publikováno v: Lithos. 151:17-34

The ca. 1525 Ma igneous Mucajai anorthosite–monzonite–granite (AMG) complex in northern Brazil is a rare manifestation of Mesoproterozoic intraplate magmatism in the northern Amazonian Craton. The complex comprises a two-phase rapakivi granite ba

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::e4dc4a96a085c1d07b4f6ef1746a936b
https://doi.org/10.1016/j.lithos.2011.07.016

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On the origin and tectonic significance of the intra-plate events of Grenvillian-type age in South America: A discussion

Autor: Nelson Joaquim Reis, Umberto G. Cordani, Colombo Celso Gaeta Tassinari, Lêda Maria Barreto Fraga, Benjamim B. Brito-Neves

Publikováno v: Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual)
Universidade de São Paulo (USP)
instacron:USP

The objective of this article is to examine the available evidence of intra-plate tectonic episodes of “Grenvillian-type age”, affecting the South-American continent, assessing their possible causal correlation with the tectonic processes occurri

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::2e247720d8dc78391034b66575ee1212
https://doi.org/10.1016/j.jsames.2009.07.002

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THE MESOPROTEROZOIC MUCAJAI ANORTHOSITE - MANGERITE - RAPAKIVI GRANITE COMPLEX, AMAZONIAN CRATON, BRAZIL

Autor: Joao Batista Sena Costa, Moacir José Buenano Macambira, Lêda Maria Barreto Fraga, Roberto Dall'Agnol

Publikováno v: The Canadian Mineralogist. 47:1469-1492

The Mesoproterozoic Mucajai anorthosite – mangerite – rapakivi granite (AMG) complex, in northern Brazil, comprises rapakivi granites, fayalite–pyroxene quartz mangerite and syenite, and a massif-type anorthosite forming an asymmetrically zoned

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::c1f1787e08440cd81a74da1d2d97610f
https://doi.org/10.3749/canmin.47.6.1469

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1.94–1.93 Ga charnockitic magmatism from the central part of the Guyana Shield, Roraima, Brazil: Single-zircon evaporation data and tectonic implications

Autor: Moacir José Buenano Macambira, Roberto Dall'Agnol, Lêda Maria Barreto Fraga, Joao Batista Sena Costa

Publikováno v: Repositório Institucional de Geociências-RIGEO
Companhia de Pesquisa de Recursos Minerais (CPRM)
instacron:CPRM

Age and origin of the charnockitic rocks of the central part of the Guyana Shield have been a matter of discussion. These rocks have been interpreted either as Transamazonian granulites metamorphosed around 2.02 Ga or as 1.56 Ga old igneous charnocki

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f1d350edd2c1c95ed65c863fc4083fdd
https://doi.org/10.1016/j.jsames.2009.02.007

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