Rapid eruption of silicic magmas from the Parana magmatic province (Brazil) did not trigger the Valanginian event

Autor(es)

Rocha, Brenda C. ^{[1, 2]} ; Davies, Joshua H. F. L. ^{[2, 3]} ; Janasi, Valdecir A. ^[1] ; Schaltegger, Urs ^[2] ; Nardy, Antonio J. R. ^[4] ; Greber, Nicolas D. ^{[2, 5]} ; Lucchetti, Ana Carolina F. ^[4] ; Polo, Liza A. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Geociencias, BR-05508080 Sao Paulo - Brazil

^[2] Univ Geneva, Dept Earth Sci, CH-1205 Geneva - Switzerland

^[3] Univ Quebec Montreal, Dept Sci Terre & Atmosphere, Montreal, PQ H2X 3Y7 - Canada

^[4] Univ Estadual Paulista, Inst Geociencias & Ciencias Exatas, BR-13506700 Rio Claro - Brazil

^[5] Univ Bern, Inst Geol Sci, CH-3012 Bern - Switzerland

• Tipo de documento: Artigo Científico
• Fonte: GEOLOGY; v. 48, n. 12, p. 1174-1178, DEC 2020.
• Citações Web of Science: 0

Resumo

The Valanginian Stage is marked by a period of global positive delta C-13 carbon cycle perturbation and biotic crises, which are collectively referred to as the Valanginian event (VE). Many attempts have been made to link the Parana-Etendeka large igneous province volcanism with the VE. However, currently there is no conclusive proof to support this hypothesis, since the timing and duration of the volcanic activity are not known with sufficient precision. In this study, we significantly revise the time scales of magmatism and environmental impact of the Parana magmatic province (PMP) in Brazil with new high-precision zircon U-Pb ages from the low-Ti Palmas and high-Ti Chapeco sequences. Our data demonstrate that significant volumes of low-Ti silicic rocks from the PMP erupted rapidly at ca. 133.6 Ma within 0.12 +/- 0.11 k.y. The age of the high-Ti Chapeco sequence from central PMP is constrained at ca. 132.9 Ma and thus extends the duration of magmatic activity by similar to 700 k.y. Our new ages are systematically younger than previous ages and postdate the major positive carbon isotope excursion, indicating that PMP silicic magmatism did not trigger the VE but could have contributed to extending its duration. Within the framework of the stratigraphic column of the PMP, the earliest low-Ti basalts could have been responsible for the VE if they are at least 0.5 m.y. older than the low-Ti silicic rocks dated herein. (AU)

• Processo FAPESP: 12/06082-6 - A província magmática Paraná-Etendeka no Brasil: relações temporais e petrológicas entre o magmatismo toleítico e alcalino e suas implicações geodinâmicas
• Beneficiário: Excelso Ruberti
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 16/23266-4 - Idade e duração do magmatismo ácido na Província Magmática Paraná a partir de datações 40Ar-39Ar em sanidina e U-Pb em zircão e badeleíta
• Beneficiário: Brenda Chung da Rocha
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 19/24872-3 - Revisando a idade do magmatismo máfico intrusivo na Província Magmática Paraná através de geocronologia U-Pb de alta precisão
• Beneficiário: Brenda Chung da Rocha
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado
• Processo FAPESP: 17/18220-8 - Refinamento da cronoestratigrafia do magmatismo silícico na Província Magmática Paraná utilizando a técnica de datação U-Pb CA-ID-TIMS em zircão
• Beneficiário: Brenda Chung da Rocha
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado