Contemporaneous alkaline and tholeiitic magmatism in the Ponta Grossa Arch, Paraná-Etendeka Magmatic Province: Constraints from U–Pb zircon/baddeleyite and 40 Ar/ 39 Ar phlogopite dating of the José Fernandes Gabbro and mafic dykes

Almeida, Vidyã Vieira de; Janasi, Valdecir de Assis; Heaman, Larry M.; Shaulis, Barry; Hollanda, Maria Helena Bezerra Maia de; Renne, Paul R.

doi:10.1016/j.jvolgeores.2017.01.018

Cited by 46 publications

(20 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The spread of ages over the concordia for up to 50 M.y. (also recorded in similar granites in the region, see for instance Vinagre et al 2014) may reflect other two causes: the presence of antecrysts (i.e., crystals from the same magmatic system previously crystallized and cannibalized by the magma that formed the dated pulse) or slightly younger lead-loss events (as demonstrated by several recent reports of U-Pb zircon ages dated by TIMS after chemical abrasion; e.g., Almeida et al 2018). At the moment, we cannot detect these effects, and thus we admit that both may respond for part of the spread.…”

Section: Age Of Granitic Magmatism In Socorro Batholithmentioning

confidence: 84%

SHRIMP U-Pb Geochronology of the Socorro Batholith and implications for the Neoproterozoic evolution in SE Brazil

2018

View full text Add to dashboard Cite

The Socorro Batholith is one of the most expressive granite manifestations associated with the Neoproterozoic evolution in SE Brazil, occupying large areas (~1,200 km 2) in the southern portion of the Socorro-Guaxupé Nappe. A U-Pb zircon SHRIMP dating program was developed to determine the ages of the main components of this batholith, identified in previous detailed mapping projects. High-K calc-alkaline (HKCA) porphyritic biotite-hornblende granites with relatively low (60-67 wt%) SiO 2 are the most voluminous component of this and other large "syn-tectonic" batholiths in the SGN (Água Limpa and Pinhal-Ipuiúna) and neighboring domains located south of it in the Apiaí and São Roque Domains of the Ribeira Fold Belt. Two samples collected in widely separated localities at the northern and southern part of the Socorro batholith yield similar ages of magmatic crystallization, respectively 610.1 ± 7.0 and 608.3 ± 6.6 Ma. A more fractioned (> 72 wt% SiO 2) granite reported in the literature as related to a younger event ("Socorro II magmatism", as opposed to the previous "Socorro I" HKCA granites) yield a precise age that is clearly older (624.4 ± 3.6 Ma), and contemporary to anatectic granites and migmatites that were produced during a prolonged period of high-grade metamorphism (635-605 Ma) that affected the SGN. Our data thus indicates that at least part of the HKCA magmatism that constitutes the Socorro batholith postdates the high-P metamorphism associated to continental collision, and may have been a source of heat and volatiles to the high-T metamorphism responsible for partial melting of the upper portions of the crustal section represented by the SGN. Two charnockitic rocks that show transitional contacts with granites of the Socorro batholith were also dated. The Socorro Charnockite is aged 641.6 ± 4.1 Ma, which overlaps those of regional orthogneisses (in part also of charnockitic character) considered as associated with a pre-collisional tectonics (subduction-related?). However, it is reported to transition to granites that are very similar to the HKCA granites of the Socorro batholith, which are yet undated. The Atibaia Charnockite has distinct geochemical affinity (lower mg# and Sr content; higher Zr), a younger age (633.3 ± 6.2 Ma), and may signal a different tectonic setting at the end of the period of plate consumption as yet poorly characterized.

show abstract

Section: Age Of Granitic Magmatism In Socorro Batholithmentioning

confidence: 84%

SHRIMP U-Pb Geochronology of the Socorro Batholith and implications for the Neoproterozoic evolution in SE Brazil

2018

View full text Add to dashboard Cite

show abstract

“…2A; Renne et al, 1992;Thiede and Vasconcelos, 2010;Pinto et al, *E-mail: brenda.rocha@usp.br 2011; Baksi, 2018). Zircon and baddeleyite ID-TIMS U-Pb ages reported for the Ourinhos trachydacite (Janasi et al, 2011) and for the Florianópolis and Ponta Grossa dike swarms (Florisbal et al, 2014;Almeida et al, 2018) range between 134.7 and 133.4 Ma ( Fig. 2A).…”

Section: Geology Geochronology and Sample Materialsmentioning

confidence: 98%

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

Rocha

Davies

Janasi

et al. 2020

Geology

Self Cite

View full text Add to dashboard Cite

The Valanginian Stage is marked by a period of global positive δ13C carbon cycle perturbation and biotic crises, which are collectively referred to as the Valanginian event (VE). Many attempts have been made to link the Paraná-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 Paraná magmatic province (PMP) in Brazil with new high-precision zircon U-Pb ages from the low-Ti Palmas and high-Ti Chapecó 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 Chapecó sequence from central PMP is constrained at ca. 132.9 Ma and thus extends the duration of magmatic activity by ~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.

show abstract

“…Almeida et al, ( 2015); Almeida et al, (2017) O acesso ao geossítio é feito pela Estrada do Pindaúba, estrada de terra em condições moderadas de conservação. O geossítio está localizado em corte de estrada e refere-se a um dique associado a importante evento intrusivo na região, com 100 metros de comprimento e 15m de altura (Figura 15A).…”

Section: Referencial Bibliográficounclassified

“…A rocha é um diabásio composto por plagioclásio e grãos intergranulares de clinopiroxênio associados com magnetita e ilmenita, sendo apatita o principal mineral acessório (Almeida et al, 2017) …”

Section: Referencial Bibliográficounclassified

See 1 more Smart Citation

Métodos de inventário e avaliação quantitativa de locais de interesse geológico no Brasil: visão geral e aplicação ao município de Cananeia, litoral sul do estado de São Paulo

Romão¹

View full text Add to dashboard Cite

DedicatóriaDedico esta obra ao meu pai que, apesar de distante, sempre esteve presente em meus pensamentos me dando força, coragem e inspiração para seguir em frente e à minha mãe, um exemplo de mulher guerreira que me incentivou e deu o suporte para lutar pelos meus ideais. AGRADECIMENTOSAgradeço à minha orientadora, Maria da Glória Motta Garcia pelo apoio e por me ajudar a direcionar este trabalho. O presente estudo visa contribuir para a compreensão da trajetória e abrangência destas pesquisas que, apesar de importantes para a Geoconservação brasileira, são numericamente pouco expressivas devido a quatro fatores preponderantes: i) por serem pontuais; ii) devido à grande extensão do território brasileiro; iii) pela Geoconservação ainda ser uma ciência recente, sendo as pesquisas nacionais representativas apenas a partir de 2010; e iv) ainda que em número crescente, são poucos os pesquisadores envolvidos com a temática. Quanto maior o número de pesquisas realizadas sobre inventários do patrimônio geológico, melhor para a divulgação da Geoconservação no contexto acadêmico, intensificando o envolvimento de geocientistas com a temática, além do diálogo e da reflexão entre os

show abstract

Contemporaneous alkaline and tholeiitic magmatism in the Ponta Grossa Arch, Paraná-Etendeka Magmatic Province: Constraints from U–Pb zircon/baddeleyite and 40 Ar/ 39 Ar phlogopite dating of the José Fernandes Gabbro and mafic dykes

Cited by 46 publications

References 45 publications

SHRIMP U-Pb Geochronology of the Socorro Batholith and implications for the Neoproterozoic evolution in SE Brazil

SHRIMP U-Pb Geochronology of the Socorro Batholith and implications for the Neoproterozoic evolution in SE Brazil

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

Métodos de inventário e avaliação quantitativa de locais de interesse geológico no Brasil: visão geral e aplicação ao município de Cananeia, litoral sul do estado de São Paulo

Contact Info

Product

Resources

About

Contemporaneous alkaline and tholeiitic magmatism in the Ponta Grossa Arch, Paraná-Etendeka Magmatic Province: Constraints from U–Pb zircon/baddeleyite and 40 Ar/ 39 Ar phlogopite dating of the José Fernandes Gabbro and mafic dykes

Cited by 46 publications

References 45 publications

SHRIMP U-Pb Geochronology of the Socorro Batholith and implications for the Neoproterozoic evolution in SE Brazil

SHRIMP U-Pb Geochronology of the Socorro Batholith and implications for the Neoproterozoic evolution in SE Brazil

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

Métodos de inventário e avaliação quantitativa de locais de interesse geológico no Brasil: visão geral e aplicação ao municí­pio de Cananeia, litoral sul do estado de São Paulo

Contact Info

Product

Resources

About

Métodos de inventário e avaliação quantitativa de locais de interesse geológico no Brasil: visão geral e aplicação ao município de Cananeia, litoral sul do estado de São Paulo