Consulta: subjectFacets:"Amazonian craton"
Registros recuperados: 2
Data/hora: 12/06/2024 03:03:49

Tectonic evolution of the southern margin of the Amazonian craton in the late Mesoproterozoic based on field relationships and zircon U-Pb geochronology
Provedor de dados: 42
Autores: RIZZOTTO,GILMAR J.; HARTMANN,LÉO A.; SANTOS,JOÃO O.S.; MCNAUGHTON,NEAL J.
New U-Pb zircon geochronological data integrated with field relationships and an airborne geophysical survey suggest that the Nova Brasilândia and Aguapeí belts are part of the same monocyclic, metaigneous and metasedimentary belt formed in the late Mesoproterozoic (1150 Ma-1110 Ma). This geological history is very similar to the within-plate origin of the Sunsás belt, in eastern Bolivia. Thus, we propose that the Nova Brasilândia, Aguapeí and Sunsás belts represent a unique geotectonic unit (here termed the Western Amazon belt) that became amalgamated at the end of the Mesoproterozoic and originated through the reactivation of a paleo-suture (Guaporé suture zone) in an intracontinental rift environment. Therefore, its geological history involves a short,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Amazonian craton; Intracontinental rift; Mesoproterozoic; Western Amazon belt; U-Pb geochronology.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652014000100057

The 1590-1520 Ma Cachoeirinha magmatic arc and its tectonic implications for the Mesoproterozoic SW Amazonian craton crustal evolution
Provedor de dados: 42
Autores: Ruiz,Amarildo S.; Geraldes,Mauro C.; Matos,João B.; Teixeira,Wilson; Van Schumus,William R.; Schmitt,Renata S.
Isotopic and chemical data of rocks from the Cachoeirinha suite provide new insights on the Proterozoic evolution of the Rio Negro/Juruena Province in SW Amazonian craton. Six U-Pb and Sm-Nd analyses in granitoid rocks of the Cachoeirinha suite yielded ages of 1587-1522 Ma and T DM model ages of 1.88-1.75 Ga (EpsilonNd values of -0.8 to +1.0). In addition, three post-tectonic plutonic rocks yielded U-Pb ages from 1485-1389 Ma (T DM of 1.77-1.74 Ga and EpsilonNd values from -1.3 to +1.7). Variations in major and trace elements of the Cachoeirinha suite rocks indicate fractional crystallization process and magmatic arc geologic setting. These results suggest the following interpretations: (1) The interval of 1590-1520 Ma represents an important magmatic...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Amazonian craton; U-Pb and Sm-Nd geochronology; Mesoproterozoic; Juvenile magmatism.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652004000400013