Arc accretion and crustal reworking from late Archean to Neoproterozoic in Northeast Brazil.
Sci Rep
; 10(1): 7855, 2020 May 12.
Article
em En
| MEDLINE
| ID: mdl-32398674
New systematic Nd isotope and U-Pb geochronology data were applied to Precambrian rocks of northeastern Brazil to produce a crustal-age distribution map for a small basement inlier (1,500 km2). The results support episodic crustal growth with five short periods of crustal formation at ca. 2.9 Ga, 2.65 Ga, 2.25 Ga, 2.0 Ga, and 0.6 Ga. Based on the frequency histogram of U-Pb zircon ages and Nd isotopic data, we suggest that about 60% of the continental crust was formed during the Archean between 2.9 Ga and 2.65 Ga. The remaining 40% of crust was generated during the Rhyacian to Neoproterozoic (~2.0-0.6 Ga). This overall continental growth is manifested by accretionary processes that involved successive accretions surrounding an older core, becoming younger toward the margin. Strikingly, this repetitive history of terrane accretion show a change from lithospheric peeling dominated accretionary setting during the late Archean to a more, modern-day akin style of arc-accretion during the Proterozoic. Similar tectonic processes are observed only in large continental areas (>1,000,000 km2) as in the North American continent basement and in the Amazonian Craton.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
Sci Rep
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Reino Unido