Geochronology and thermochronology of the gneisses of the Brasiliano/Pan-African Araguaia Belt: Records of exhumation of West Gondwana and Pangea break up

Autor(es)

Dias, A. N. C. ^[1] ; Moura, C. A. V. ^[2] ; Milhomem Neto, J. M. ^[3] ; Chemale, Jr., F. ^[4] ; Girelli, T. J. ^[4] ; Masuyama, K. M. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, CCTS, Dept Fis Quim & Matemat, Campus Sorocaba, Rodovia Joao Leme dos Santos, BR-18052780 Sorocaba, SP - Brazil

^[2] UFPA, Inst Geociencias, BR-66075900 Belem, Para - Brazil

^[3] UFPA, Inst Geociencias, Programa Posgrad Geol & Geoquim, BR-66075900 Belem, Para - Brazil

^[4] Univ Vale Rio dos Sinos, Programa Posgrad Geol, BR-93022000 Sao Leopoldo, RS - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of South American Earth Sciences; v. 80, p. 174-191, DEC 2017.
• Citações Web of Science: 6

Resumo

The 1200 km long Araguaia Belt, central-north Brazil, was formed as a result of the Neoproterozoic (Ediacaran) to Early Cambrian collage of West Gondwana and has several dome structures in whose nuclei crop out basement inliers of Archean and Paleoproterozoic orthogneisses. Thus, the orthogneisses from Lontra, Cocalandia, Colmeia and Cantao dome structures were selected for fission-track thermo-chronology and U-Pb double dating. Three Archean magmatic episodes ranging from 2830.9 +/- 6.9 Ma (Colmeia dome) to 2905 +/- 5.1 Ma (Lontra dome) and one Paleoproterozoic magmatic event at 1835 31 Ma (Cantao dome) are recognized by U-Pb LA-MC-ICP-MS zircon dating. Fission-track thermochronology in zircon permitted to identify three well-defined age populations, which correspond to major regional geological events. The older population (489 +/- 15 Ma to 498 +/- 8Ma) records the exhumation process and the orogenetic collapse of the Araguaia Belt. The intermediate population (331 +/- 8 Ma to 345 +/- 13 Ma) is related to the Gondwanides orogeny which affected the western margin of Gondwana and therefore the interior of South American. Finally, the younger fission track ages (197 3 Ma, 197 4 Ma, 198 2 Ma and 208 10 Ma) reflect crustal heating around 200 Ma, which is associated with the Lower Jurassic Mosquito tholeiitic magmatism and extended the influence of the Central Atlantic Magmatic Province to the Araguaia Belt. This mafic magmatism has been recognized in different regions of the South American and was an important source of heat for hydrocarbon generation in some Paleozoic intracratonic basins. (C) 2017 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 14/13792-5 - Estudo da evolução de bacias sedimentares brasileiras a partir da termocronologia por traços de fissão em zircão
• Beneficiário: Airton Natanael Coelho Dias
• Modalidade de apoio: Auxílio à Pesquisa - Regular