Results 171 to 180 of about 848 (205)

Emplacement and deformation of the A-type Madeira granite (Amazonian Craton, Brazil)

Lithos, 2017
Abstract The Madeira granite is one of the Paleoproterozoic (1.82 Ga) A-type granite intrusions in the Amazonian Craton. It is elongated in the NE–SW direction and is composed of four facies. Classical structural techniques and the anisotropy of magnetic susceptibility (AMS) method were applied to the study of its internal fabric.
Astrid Siachoque, Carlos Alejandro Salazar, Ricardo Trindade   +2 more
openaire   +1 more source

Geochronology of the Archean Tumucumaque Complex, Amapá Terrane, Amazonian Craton, Brazil

Journal of South American Earth Sciences, 2018
Abstract U-Pb and Lu-Hf isotopic studies were performed in igneous zircon crystals from orthogneisses, metagranodiorites and a gabbro of the Tumucumaque Complex, in Vila Nova region, south of Amapa state, Brazil. The complex is located in the southeastern region of the Guyana Shield, northeastern portion of the Amazonian Craton.
Cristiano Borghetti, Ruy P. Philipp, Persio Mandetta, Itiana B. Hoffmann   +3 more
openaire   +1 more source

The Archean granulite-enderbite complex of the northern Carajás province, Amazonian craton (Brazil): Origin and implications for crustal growth and cratonization

Lithos, 2019
Abstract The central portion of the Canaa dos Carajas domain (Ouro Verde area) exhibits a peculiar scenario involving two units of orthopyroxene-bearing sodic rocks: (i) the Mesoarchean Ouro Verde felsic granulite with protolith crystallization and metamorphism ages of 3.05–2.93 Ga and 2.89–2.84 Ga, respectively, and (ii) the Neoarchean Cafe ...
Bhrenno Marangoanha, Davis Carvalho de Oliveira, Roberto Dall’Agnol   +2 more
openaire   +1 more source

From Mesoarchean drips to modern–style tectonics in the Carajás Province, Amazonian Craton

Journal of South American Earth Sciences, 2020
Abstract The beginning of modern–style plate tectonics on Earth is not a consensus, but many authors suggest that it happened transitionally, from 3.2 to 2.5 Ga. In the Amazonian Craton, Brazil, the contrasting crustal architecture of the Rio Maria and the Carajas domains is marked by dome–and–keel and linear belt, respectively, which may represent a
Felipe Grandjean da Costa, Patrick Araújo dos Santos, Isabelle Cavalcanti Corrêa de Oliveira Serafim, Iago Sousa Lima Costa, Sherissa Roopnarain   +4 more
openaire   +1 more source

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

The Canadian Mineralogist, 2009
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 igneous complex without counterpart in the Amazonian craton.
L. M. B. Fraga, R. Dall'Agnol, J. B. S. Costa, M. J. B. Macambira   +3 more
openaire   +1 more source

Fissural mafic magmatism on southwestern Amazonian Craton: Petrogenesis and 40Ar-39Ar geochronology

Journal of South American Earth Sciences, 2019
Abstract Expressive occurrences of sills and mafic dyke swarms as a result of tafrogenetic processes that led to break-up or attempted break-up of continental crust are found on the south and southwestern Amazonian Craton. This work focus on the magmatic-tectonic processes that formed the Salto do Ceu, Huanchaca, and Rancho de Prata suites. The Salto
Gabrielle Aparecida Lima, Moacir José Buenano Macambira, Maria Zélia Aguiar Sousa, Amarildo Salina Ruiz, Manoel Souza D'Agrella-Filho   +4 more
openaire   +1 more source

The Roraima Alkaline Province: A cretaceous alkaline province in the Amazonian Craton

Geochemistry, 2022
Raisa Fagundes de Figueiredo, Rogério Guitarrari Azzone, Ticiano José Saraiva dos Santos   +2 more
openaire   +1 more source

LOMAGUNDI CARBON-ISOTOPE EXCURSION ON THE AMAZONIAN CRATON

Geological Society of America Abstracts with Programs, 2017
Andrey Bekker, Gabriel Valentim Berni, Alexandre R. Cabrial, Donald Davis, Juha Karhu   +4 more
openaire   +1 more source

Early Orosirian belts of the central Guiana Shield, northern Amazonian Craton: U-Pb geochronology and tectonic implications

Precambrian Research
The Cauarane-Coeroeni Belt (CCB), the Orocaima Igneous Belt (OIB) and the Rio Urubu Belt (RUB) are the main tectonic features of the central part of the Guiana Shield. The CCB is a sinuous NW-SE/NE-SW/NW-SE trending high-grade supracrustal belt, bordered to the north by the OIB, formed by volcanics and high-crustal level granitoids, and to the south by
Maria Fraga, Lêda, Cordani, Umberto, Maria Dreher, Ana, Sato, Kei, Joaquim Reis, Nelson, Nadeau, Serge, De Roever, Emond, Kroonenberg, Salomon, Camara Maurer, Victor   +8 more
openaire   +2 more sources

Insights on the magmatism, crustal evolution and metallogenesis of the Amazonian craton

Journal of South American Earth Sciences, 2009
Roberto Dall’Agnol, Reinhardt A. Fuck, Raimundo Netuno Nobre Villas   +2 more
openaire   +1 more source